@inproceedings{HessLuanSchwarteetal.2001, author = {Hess, Holger and Luan, Xuming and Schwarte, Rudolf and Zhang, Zhigang and Xu, Zhanping and Heinol, Horst-Guenther and Buxbaum, Bernd and Ringbeck, Thorsten}, title = {Three-dimensional intelligent sensing based on the PMD technology}, series = {Sensors, Systems, and Next-Generation Satellites V : 17 - 20 September 2001, Toulouse, France. - (SPIE proceedings series ; 4540)}, booktitle = {Sensors, Systems, and Next-Generation Satellites V : 17 - 20 September 2001, Toulouse, France. - (SPIE proceedings series ; 4540)}, editor = {Fujisada, Hiroyuki}, publisher = {SPIE}, address = {Bellingham, Wash.}, isbn = {0-8194-4265-8}, issn = {0038-7355}, pages = {482 -- 488}, year = {2001}, language = {en} } @article{Heuermann1996, author = {Heuermann, Holger}, title = {Sure Methods of On-Wafer Scattering Parameter Measurements with Self-Calibration Procedures}, pages = {136 -- 145}, year = {1996}, language = {en} } @article{Heuermann2003, author = {Heuermann, Holger}, title = {GSOLT: the calibration procedure for all multi-port vector network analyzers}, series = {IEEE MTT-S International Microwave Symposium digest : Philadelphia, Pennsylvania, 8 - 13 June 2003 ; [including: 2003 International Microwave Symposium digest, vol. 1-3, RF Integrated Circuit Symposium digest, Automatic RF Techniques Group Symposium digest . Vol. 3}, journal = {IEEE MTT-S International Microwave Symposium digest : Philadelphia, Pennsylvania, 8 - 13 June 2003 ; [including: 2003 International Microwave Symposium digest, vol. 1-3, RF Integrated Circuit Symposium digest, Automatic RF Techniques Group Symposium digest . Vol. 3}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {0-780-37696-X}, pages = {1815 -- 1818}, year = {2003}, language = {en} } @article{Heuermann1997, author = {Heuermann, Holger}, title = {Microwave On-Wafer Measurements with Activ Needle Probe Tips}, pages = {208 -- 214}, year = {1997}, language = {en} } @article{Heuermann2006, author = {Heuermann, Holger}, title = {Multiport S-parameter calculation from two-port network analyzer measurements with or without switch matrix}, series = {ARFTG Conference, 2006 67th, San Francisco, CA}, journal = {ARFTG Conference, 2006 67th, San Francisco, CA}, isbn = {978-0-7803-9529-9}, pages = {219 -- 222}, year = {2006}, language = {en} } @article{Heuermann2006, author = {Heuermann, Holger}, title = {Verringerung des Phasenrauschens von Oszillatoren durch Dual-Mode-Resonatoren}, series = {HF-Report. 20 (2006), H. 5-6}, journal = {HF-Report. 20 (2006), H. 5-6}, isbn = {1431-827X}, pages = {43 -- 48}, year = {2006}, language = {en} } @article{Heuermann2008, author = {Heuermann, Holger}, title = {A 14 W SPST Switch with Four PIN-Diodes In a 0402-SMD-Package}, isbn = {978-3-8007-3086-5}, pages = {318 -- 321}, year = {2008}, language = {en} } @article{Heuermann2004, author = {Heuermann, Holger}, title = {A Synthesis Technique for Mono- and Mixed-Mode Symmetrical Filter}, series = {Conference proceedings : Tuesday 12th, Wednesday 13th and Thursday 14th October, [RAI International Exhibition and Congress Centre, Amsterdam ; part of European Microwave Week 2004] / EuMA, European Microwave Association . Vol. 1}, journal = {Conference proceedings : Tuesday 12th, Wednesday 13th and Thursday 14th October, [RAI International Exhibition and Congress Centre, Amsterdam ; part of European Microwave Week 2004] / EuMA, European Microwave Association . Vol. 1}, publisher = {Horizon House Publ}, address = {London}, isbn = {1-580-53992-0}, pages = {309 -- 312}, year = {2004}, language = {en} } @article{Heuermann1995, author = {Heuermann, Holger}, title = {LZY: A Self-Calibration Approach in Competition to the LRM Method for On-Wafer Measurements}, pages = {129 -- 136}, year = {1995}, language = {en} } @article{Heuermann2008, author = {Heuermann, Holger}, title = {Dual mode radio: A new tranceiver architecture for UWB and 60 GHz-applications}, series = {European Conference on Wireless Technology, 2008. EuWiT 2008.}, journal = {European Conference on Wireless Technology, 2008. EuWiT 2008.}, isbn = {978-2-87487-008-8}, pages = {147 -- 150}, year = {2008}, language = {en} } @article{Heuermann2008, author = {Heuermann, Holger}, title = {Calibration of a Network Analyzer Without a Thru Connection for Nonlinear and Multiport Measurements}, series = {IEEE Transactions on Microwave Theory and Techniques. 56 (2008), H. 11, 1}, journal = {IEEE Transactions on Microwave Theory and Techniques. 56 (2008), H. 11, 1}, isbn = {0018-9480}, pages = {2505 -- 2510}, year = {2008}, language = {en} } @article{Heuermann1999, author = {Heuermann, Holger}, title = {Calibration procedures with series impedances and unknown lines simplify on-wafer measurements}, series = {IEEE transactions on microwave theory and techniques : MTT ; a publication of the IEEE Microwave Theory and Techniques Society. 47 (1999), H. 1}, journal = {IEEE transactions on microwave theory and techniques : MTT ; a publication of the IEEE Microwave Theory and Techniques Society. 47 (1999), H. 1}, isbn = {0018-9480}, pages = {1 -- 5}, year = {1999}, language = {en} } @article{HeuermannBaumannFauthetal.1994, author = {Heuermann, Holger and Baumann, F.-M. and Fauth, G. and Albert, M.}, title = {Results of Network Analyzer Measurements with Leakage Errors Corrected with the TMS-15-Term Procedure}, series = {On-Line Moisture Analysis of Raw Coal}, journal = {On-Line Moisture Analysis of Raw Coal}, pages = {1361 -- 1364}, year = {1994}, language = {en} } @article{HeuermannEmmrichBongartz2022, author = {Heuermann, Holger and Emmrich, Thomas and Bongartz, Simon}, title = {Microwave spark plug to support ignitions with high compression ratios}, series = {IEEE Transactions on Plasma Science}, journal = {IEEE Transactions on Plasma Science}, number = {Early Access}, publisher = {IEEE}, issn = {1939-9375}, doi = {10.1109/TPS.2022.3183690}, pages = {1 -- 6}, year = {2022}, abstract = {Upcoming gasoline engines should run with a larger number of fuels beginning from petrol over methanol up to gas by a wide range of compression ratios and a homogeneous charge. In this article, the microwave (MW) spark plug, based on a high-speed frequency hopping system, is introduced as a solution, which can support a nitrogen compression ratio up to 1:39 in a chamber and more. First, an overview of the high-speed frequency hopping MW ignition and operation system as well as the large number of applications are presented. Both gives an understanding of this new base technology for MW plasma generation. Focus of the theoretical part is the explanation of the internal construction of the spark plug, on the achievable of the high voltage generation as well as the high efficiency to hold the plasma. In detail, the development process starting with circuit simulations and ending with the numerical multiphysics field simulations is described. The concept is evaluated with a reference prototype covering the frequency range between 2.40 and 2.48 GHz and working over a large power range from 20 to 200 W. A larger number of different measurements starting by vector hot-S11 measurements and ending by combined working scenarios out of hot temperature, high pressure and charge motion are winding up the article. The limits for the successful pressure tests were given by the pressure chamber. Pressures ranged from 1 to 39 bar and charge motion up to 25 m/s as well as temperatures from 30◦ to 125◦.}, language = {en} } @article{HeuermannErkens2006, author = {Heuermann, Holger and Erkens, H.}, title = {Novel RF switch concepts for differential wireless communications frontends. Erkens, H.; Heuermann, H.}, series = {IEEE Transactions on Microwave Theory and Techniques. 54 (2006), H. 6, Part 1}, journal = {IEEE Transactions on Microwave Theory and Techniques. 54 (2006), H. 6, Part 1}, isbn = {0018-9480}, pages = {2376 -- 2382}, year = {2006}, language = {en} } @article{HeuermannErkens2007, author = {Heuermann, Holger and Erkens, H.}, title = {Mixed-Mode Chain Scattering Parameters: Theory and Verification}, series = {IEEE Transactions on Microwave Theory and Techniques}, volume = {55}, journal = {IEEE Transactions on Microwave Theory and Techniques}, number = {8}, publisher = {IEEE}, address = {New York}, isbn = {0018-9480}, doi = {10.1109/TMTT.2007.902587}, pages = {1704 -- 1708}, year = {2007}, abstract = {Chain scattering parameters or T-parameters are a useful tool for calculating cascaded two-ports. With the increasing importance of mixed-mode S-parameters, a need for converting the T-parameters from their unbalanced form into a balanced form emerges for suiting both common and differential mode waves, as well as the mode conversion. This paper presents the derivation of the equations for transformations between mixed-mode S- and T-parameters for a mixed-mode two-port. Although derived in a way very similar to monomode T-parameters, no simplifications were necessary. Measurement results exemplify the quality of the T-parameter transformation under real-life conditions.}, language = {en} } @article{HeuermannErkens2004, author = {Heuermann, Holger and Erkens, Holger}, title = {Blocking structures for mixed-mode systems. / Erkens, Holger ; Heuermann, Holger}, series = {Conference proceedings : Tuesday 12th, Wednesday 13th and Thursday 14th October, [RAI International Exhibition and Congress Centre, Amsterdam ; part of European Microwave Week 2004] / EuMA, European Microwave Association. Vol. 1}, journal = {Conference proceedings : Tuesday 12th, Wednesday 13th and Thursday 14th October, [RAI International Exhibition and Congress Centre, Amsterdam ; part of European Microwave Week 2004] / EuMA, European Microwave Association. Vol. 1}, publisher = {Horizon House Publ.}, address = {London}, isbn = {1-580-53992-0}, pages = {297 -- 300}, year = {2004}, language = {en} } @inproceedings{HeuermannFinger2014, author = {Heuermann, Holger and Finger, Torsten}, title = {2.45 GHz Plasma Powered Spark Plug by Thermal and EM-Optimization}, pages = {30 Folien}, year = {2014}, language = {en} } @incollection{HeuermannFinger2014, author = {Heuermann, Holger and Finger, Torsten}, title = {Microwave Spark Plug for Very High-Pressure Conditions}, series = {Ignition systems for gasoline engines}, booktitle = {Ignition systems for gasoline engines}, editor = {G{\"u}nther, Michael}, publisher = {DCM Druck}, address = {Meckenheim}, pages = {269 -- 282}, year = {2014}, language = {en} } @inproceedings{HeuermannHarzheimMuehmel2021, author = {Heuermann, Holger and Harzheim, Thomas and M{\"u}hmel, Marc}, title = {A maritime harmonic radar search and rescue system using passive and active tags}, series = {2020 17th European Radar Conference (EuRAD)}, booktitle = {2020 17th European Radar Conference (EuRAD)}, publisher = {IEEE}, address = {New York, NY}, isbn = {978-2-87487-061-3}, doi = {10.1109/EuRAD48048.2021.00030}, pages = {73 -- 76}, year = {2021}, abstract = {This article introduces a new maritime search and rescue system based on S-band illumination harmonic radar (HR). Passive and active tags have been developed and tested attached to life jackets and a rescue boat. This system was able to detect and range the active tags up to a range of 5800 m in tests on the Baltic Sea with an antenna input power of only 100 W. All electronic GHz components of the system, excluding the S-band power amplifier, were custom developed for this purpose. Special attention is given to the performance and conceptual differences between passive and active tags used in the system and integration with a maritime X-band navigation radar is demonstrated.}, language = {en} } @article{HeuermannHillebrandSadeghfam2008, author = {Heuermann, Holger and Hillebrand, J{\"u}rgen and Sadeghfam, Arash}, title = {Novel Concept of a Digital SigmaDelta-PLL-Phase-Shift-Modulator / Hillebrand, J{\"u}rgen ; Sadeghfam, Arash ; Heuermann, Holger}, isbn = {978-3-8007-3086-5}, pages = {123 -- 126}, year = {2008}, language = {en} } @article{HeuermannHoltrup2009, author = {Heuermann, Holger and Holtrup, Stephan}, title = {Fundamentals and ignition of a microplasma at 2.45 GHZ / Holtrup, Stephan ; Heuermann, Holger}, series = {European Microwave Conference, 2009 : EuMC 2009 ; Sept. 29, 2009 - Oct. 1, 2009, Rome, Italy ; part of European Microwave Week (EuMW) / sponsored by EuMA, European Microwave Association ... Endorsed by IEEE}, journal = {European Microwave Conference, 2009 : EuMC 2009 ; Sept. 29, 2009 - Oct. 1, 2009, Rome, Italy ; part of European Microwave Week (EuMW) / sponsored by EuMA, European Microwave Association ... Endorsed by IEEE}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4244-4748-0}, pages = {1607 -- 1609}, year = {2009}, language = {en} } @article{HeuermannIbrahim2009, author = {Heuermann, Holger and Ibrahim, Irfan}, title = {Improvements in the flicker noise reduction technique for osillator designs / Ibrahim, Irfan ; Heuermann, Holger}, series = {European Microwave Conference, 2009 : EuMC 2009 ; Sept. 29, 2009 - Oct. 1, 2009, Rome, Italy ; part of European Microwave Week (EuMW) / sponsored by EuMA, European Microwave Association ... Endorsed by IEEE}, journal = {European Microwave Conference, 2009 : EuMC 2009 ; Sept. 29, 2009 - Oct. 1, 2009, Rome, Italy ; part of European Microwave Week (EuMW) / sponsored by EuMA, European Microwave Association ... Endorsed by IEEE}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4244-4748-0}, pages = {1215 -- 1218}, year = {2009}, language = {en} } @article{HeuermannIbrahim2008, author = {Heuermann, Holger and Ibrahim, Irfan}, title = {Novel theory and architecture of a vector signal generator implemented with two PLLs / Ibrahim, Irfan ; Heuermann, Holger}, series = {European Conference on Wireless Technology, 2008. EuWiT 2008.}, journal = {European Conference on Wireless Technology, 2008. EuWiT 2008.}, isbn = {978-2-87487-008-8}, pages = {85 -- 88}, year = {2008}, language = {en} } @article{HeuermannIbrahimHillebrand2007, author = {Heuermann, Holger and Ibrahim, Irfan and Hillebrand, J.}, title = {Vector-Signal-Generator with Two ?'?'-PLL's / Ibrahim, I. ; Hillebrand, J. ; Heuermann, H.}, series = {European Conference on Wireless Technologies, 2007. ECWT 2007 ; 8 - 10 October 2007 Munich, Germany}, journal = {European Conference on Wireless Technologies, 2007. ECWT 2007 ; 8 - 10 October 2007 Munich, Germany}, isbn = {978-2-87487-003-3}, pages = {1 -- 4}, year = {2007}, language = {en} } @article{HeuermannLuenebach2005, author = {Heuermann, Holger and L{\"u}nebach, M.}, title = {A Novel Dual-Mode-Design for Push-Push Oscillators with Improved Phase Noise Performance. Heuermann, Holger; L{\"u}nebach, M.}, series = {Conference proceedings : 3 - 7 October 2005, CNIT la D{\´e}fense, Paris, France; [comprises the] 35th European Microwave Conference 2005 ; The European Conference on Wireless Technology 2005 ; European Radar Conference 2005 ; GAAS 2005, The European Gallium A. Vol. 1}, journal = {Conference proceedings : 3 - 7 October 2005, CNIT la D{\´e}fense, Paris, France; [comprises the] 35th European Microwave Conference 2005 ; The European Conference on Wireless Technology 2005 ; European Radar Conference 2005 ; GAAS 2005, The European Gallium A. Vol. 1}, publisher = {Horizon House Publ}, address = {London}, isbn = {2-9600551-0-1}, pages = {4 pp.}, year = {2005}, language = {en} } @article{HeuermannPetersSchmitzetal.2005, author = {Heuermann, Holger and Peters, N. and Schmitz, T. and Sadeghfam, Arash}, title = {Concept of Balanced Antennas with Load-Invariant Base Impedance Using a Two Element LC-Coupler. Peters, N., Schmitz, Th., Sadeghfam, A., Heuermann, H.}, series = {Proceedings of the European microwave association : journal of the European microwave association}, journal = {Proceedings of the European microwave association : journal of the European microwave association}, publisher = {PLUS}, address = {Pisa}, pages = {117 -- 122}, year = {2005}, language = {en} } @article{HeuermannRumiantsevSchott2004, author = {Heuermann, Holger and Rumiantsev, A. and Schott, S.}, title = {Advanced on-wafer multiport calibration methods for mono- and mixed-mode device characterization}, series = {On wafer characterization : 63rd ARFTG conference digest, spring 2004, 11 June 2004, Fort Worth, TX / Automatic RF Techniques Group. [Conference chair: John Cable. Publication chair: J. G. Burns]}, journal = {On wafer characterization : 63rd ARFTG conference digest, spring 2004, 11 June 2004, Fort Worth, TX / Automatic RF Techniques Group. [Conference chair: John Cable. Publication chair: J. G. Burns]}, publisher = {IEEE Operations Center}, address = {Piscataway, NJ}, isbn = {0-7803-8371-0}, pages = {91 -- 96}, year = {2004}, language = {en} } @article{HeuermannSadeghfam2008, author = {Heuermann, Holger and Sadeghfam, Arash}, title = {Electrically tunable bandpass filter with integrated carrier suppression for UHF RFID systems / Sadeghfam, Arash ; Heuermann, Holger}, series = {European Microwave Conference, 2008, EuMC 2008, 38th}, journal = {European Microwave Conference, 2008, EuMC 2008, 38th}, isbn = {978-2-87487-006-4}, pages = {1727 -- 1730}, year = {2008}, language = {en} } @article{HeuermannSadeghfam2009, author = {Heuermann, Holger and Sadeghfam, Arash}, title = {Enhanced system architecture for rugged wide band data transmission / Sadeghfam, A. ; Heuermann, H.}, series = {European Radar Conference, 2009 : EuRAD 2009 ; Sept. 30 - Oct. 2 2009, Rome, Italy ; part of the European Microwave Week (EuMW) / sponsored by EuMA, European Microwave Association}, journal = {European Radar Conference, 2009 : EuRAD 2009 ; Sept. 30 - Oct. 2 2009, Rome, Italy ; part of the European Microwave Week (EuMW) / sponsored by EuMA, European Microwave Association}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-2-87487-014-9}, pages = {347 -- 350}, year = {2009}, language = {en} } @article{HeuermannSadeghfam2007, author = {Heuermann, Holger and Sadeghfam, Arash}, title = {On the design of multimode integrated circuits in multilayered processes / Sadeghfam, A. ; Heuermann, H.}, series = {European Microwave Conference, 2007, 9-12 Oct. 2007}, journal = {European Microwave Conference, 2007, 9-12 Oct. 2007}, isbn = {978-2-87487-001-9}, pages = {516 -- 519}, year = {2007}, language = {en} } @article{HeuermannSadeghfam2008, author = {Heuermann, Holger and Sadeghfam, Arash}, title = {Electrically tunable bandpass filter with integrated carrier suppression for UHF RFID systems / Sadeghfam, Arash ; Heuermann, Holger}, series = {European Conference on Wireless Technology, 2008. EuWiT 2008.}, journal = {European Conference on Wireless Technology, 2008. EuWiT 2008.}, isbn = {978-2-87487-008-8}, pages = {306 -- 309}, year = {2008}, language = {en} } @article{HeuermannSadeghfam2004, author = {Heuermann, Holger and Sadeghfam, Arash}, title = {Novel balanced inductor for compact differential systems / Sadeghfam, Arash; Heuermann, Holger}, series = {Conference proceedings : Tuesday 12th, Wednesday 13th and Thursday 14th October, [RAI International Exhibition and Congress Centre, Amsterdam ; part of European Microwave Week 2004] / EuMA, European Microwave Association}, journal = {Conference proceedings : Tuesday 12th, Wednesday 13th and Thursday 14th October, [RAI International Exhibition and Congress Centre, Amsterdam ; part of European Microwave Week 2004] / EuMA, European Microwave Association}, publisher = {Horizon House Publ.}, address = {London}, isbn = {1-580-53992-0}, pages = {709 -- 712}, year = {2004}, language = {en} } @article{HeuermannSadeghfamBoehm2005, author = {Heuermann, Holger and Sadeghfam, Arash and Boehm, H.}, title = {Ultra Compact Multi-Mode Filter with Novel Rat-Race Inductor. Sadeghfam, Arash; Heuermann, Holger; Boehm, H.}, series = {Conference proceedings : 3 - 7 October 2005, CNIT la D{\´e}fense, Paris, France; [comprises the] 35th European Microwave Conference 2005 ; The European Conference on Wireless Technology 2005 ; European Radar Conference 2005 ; GAAS 2005, The European Gallium A. Vol. 2}, journal = {Conference proceedings : 3 - 7 October 2005, CNIT la D{\´e}fense, Paris, France; [comprises the] 35th European Microwave Conference 2005 ; The European Conference on Wireless Technology 2005 ; European Radar Conference 2005 ; GAAS 2005, The European Gallium A. Vol. 2}, publisher = {Horizon House Publ}, address = {London}, isbn = {2-9600551-0-1}, pages = {4 pp.}, year = {2005}, language = {en} } @inproceedings{HeuermannSadeghfamFinger2013, author = {Heuermann, Holger and Sadeghfam, Arash and Finger, Torsten}, title = {Alternative ignition system based on microwave plasma}, series = {Advanced ignition systems for gasoline engines : [Vortr{\"a}ge der 1st International Conference Advanced Ignition Systems for Gasoline Engines - 1. Internationale Tagung Z{\"u}ndsysteme f{\"u}r Ottomotoren, 12.-13. November 2012, Berlin]}, booktitle = {Advanced ignition systems for gasoline engines : [Vortr{\"a}ge der 1st International Conference Advanced Ignition Systems for Gasoline Engines - 1. Internationale Tagung Z{\"u}ndsysteme f{\"u}r Ottomotoren, 12.-13. November 2012, Berlin]}, publisher = {Expert-Verl.}, address = {Renningen}, organization = {International Conference Advanced Ignition Systems for Gasoline Engines <1, 2012, Berlin>}, isbn = {9783816931904}, pages = {95 -- 103}, year = {2013}, language = {en} } @article{HeuermannSchiek1994, author = {Heuermann, Holger and Schiek, B.}, title = {Robust Algorithms for Txx Network Analyzer Self-Calibration Procedures}, series = {IEEE transactions on instrumentation and measurement : IM / Institute of Electrical and Electronics Engineers, Instrumentation and Measurement Group. 43 (1994), H. 1}, journal = {IEEE transactions on instrumentation and measurement : IM / Institute of Electrical and Electronics Engineers, Instrumentation and Measurement Group. 43 (1994), H. 1}, isbn = {0018-9456}, pages = {18 -- 23}, year = {1994}, language = {en} } @article{HeuermannSchiek1997, author = {Heuermann, Holger and Schiek, B.}, title = {Results of network analyzer measurements with leakage errors-corrected with direct calibration techniques}, series = {IEEE transactions on instrumentation and measurement : IM / Institute of Electrical and Electronics Engineers, Instrumentation and Measurement Group. 46 (1997), H. 5}, journal = {IEEE transactions on instrumentation and measurement : IM / Institute of Electrical and Electronics Engineers, Instrumentation and Measurement Group. 46 (1997), H. 5}, isbn = {0018-9456}, pages = {1120 -- 1127}, year = {1997}, language = {en} } @article{HeuermannSchiek1993, author = {Heuermann, Holger and Schiek, B.}, title = {Procedures for the Determination of the Scattering Parameters for Network Analyzer Calibration}, series = {IEEE transactions on instrumentation and measurement : IM / Institute of Electrical and Electronics Engineers, Instrumentation and Measurement Group. 42 (1993), H. 2}, journal = {IEEE transactions on instrumentation and measurement : IM / Institute of Electrical and Electronics Engineers, Instrumentation and Measurement Group. 42 (1993), H. 2}, isbn = {0018-9456}, pages = {528 -- 531}, year = {1993}, language = {en} } @article{HeuermannSchiek1997, author = {Heuermann, Holger and Schiek, B.}, title = {15-term self-calibration methods for the error-correction of on-wafer measurements}, series = {IEEE transactions on instrumentation and measurement : IM / Institute of Electrical and Electronics Engineers, Instrumentation and Measurement Group. 46 (1997), H. 5}, journal = {IEEE transactions on instrumentation and measurement : IM / Institute of Electrical and Electronics Engineers, Instrumentation and Measurement Group. 46 (1997), H. 5}, isbn = {0018-9456}, pages = {1105 -- 1110}, year = {1997}, language = {en} } @article{HeuermannSchiek1995, author = {Heuermann, Holger and Schiek, B.}, title = {Error corrected impedance measurements with a network analyzer}, series = {IEEE transactions on instrumentation and measurement : IM / Institute of Electrical and Electronics Engineers, Instrumentation and Measurement Group. 44 (1995), H. 2}, journal = {IEEE transactions on instrumentation and measurement : IM / Institute of Electrical and Electronics Engineers, Instrumentation and Measurement Group. 44 (1995), H. 2}, isbn = {0018-9456}, pages = {295 -- 299}, year = {1995}, language = {en} } @article{HeuermannSchiek1995, author = {Heuermann, Holger and Schiek, Burkhard}, title = {The double-LNN Calibration technique for scattering parameter measurements of microstrip devices}, series = {Conference proceedings}, journal = {Conference proceedings}, publisher = {NEXUS House}, address = {Kent}, pages = {343 -- 347}, year = {1995}, language = {en} } @article{HeuermannSchiek1994, author = {Heuermann, Holger and Schiek, Burkhard}, title = {Calibration of network analyser measurements with leakage errors}, series = {Electronics letters. 30 (1994), H. 1}, journal = {Electronics letters. 30 (1994), H. 1}, isbn = {0013-5194}, pages = {52 -- 53}, year = {1994}, language = {en} } @article{HeuermannSchiek1994, author = {Heuermann, Holger and Schiek, Burkhard}, title = {Results of Network Analyzer Measurements with Leakage Errors Corrected with the TMS-15-Term Procedure}, pages = {1361 -- 1364}, year = {1994}, language = {en} } @article{HeuermannSchiek1994, author = {Heuermann, Holger and Schiek, Burkhard}, title = {Scattering Parameter Measurements of Microstrip Devices using the Double-LNN Calibration Technique}, series = {Conference proceedings : [Palais des Festivals et des Congr{\`e}s Cannes, France, 5 - 8 September 1994]}, journal = {Conference proceedings : [Palais des Festivals et des Congr{\`e}s Cannes, France, 5 - 8 September 1994]}, publisher = {Nexus Business Communications}, address = {Swanley}, isbn = {0-9518032-5-5}, year = {1994}, language = {en} } @article{HeuermannSchiek1992, author = {Heuermann, Holger and Schiek, Burkhard}, title = {The In-Fixture Calibration Procedure Line-Network-Network-LNN}, series = {Conference proceedings : monday 6th to thursday 9th september 1993, Palacio de Congresos, Madrid, Spain ; [the international conference and exhibition designed for the Microwave Community]}, journal = {Conference proceedings : monday 6th to thursday 9th september 1993, Palacio de Congresos, Madrid, Spain ; [the international conference and exhibition designed for the Microwave Community]}, publisher = {Reed Exhibition Companies}, address = {Tunbridge Wells}, isbn = {0-946821-23-2}, pages = {500 -- 505}, year = {1992}, language = {en} } @article{HeuermannSchiek1992, author = {Heuermann, Holger and Schiek, Burkhard}, title = {A Fast and Robust Procedure for the Determination of the Scattering Parameters for Network Analyzer Calibration}, address = {Paris}, pages = {373 -- 374}, year = {1992}, language = {en} } @article{HeuermannSchiek1992, author = {Heuermann, Holger and Schiek, Burkhard}, title = {LNN (Line-Network-Network): Verfahren zur Kalibrierung von Netzwerkanalysatoren}, series = {Kleinheubacher Berichte : Vortr{\"a}ge und Berichte der gemeinsamen Tagung des U.R.S.I.-Landesausschusses in der Bundesrepublik Deutschland / Hrsg.: Deutsche Telekom AG. 36. 1992 (1992)}, journal = {Kleinheubacher Berichte : Vortr{\"a}ge und Berichte der gemeinsamen Tagung des U.R.S.I.-Landesausschusses in der Bundesrepublik Deutschland / Hrsg.: Deutsche Telekom AG. 36. 1992 (1992)}, pages = {327 -- 335}, year = {1992}, language = {en} } @article{HeuermannSchiek1997, author = {Heuermann, Holger and Schiek, Burkhard}, title = {Line Network Network (LNN): an alternative in-fixture calibration procedure}, series = {IEEE transactions on microwave theory and techniques : MTT ; a publication of the IEEE Microwave Theory and Techniques Society. 45 (1997), H. 3}, journal = {IEEE transactions on microwave theory and techniques : MTT ; a publication of the IEEE Microwave Theory and Techniques Society. 45 (1997), H. 3}, isbn = {0018-9480}, pages = {408 -- 413}, year = {1997}, language = {en} } @article{HeuermannSchiek1993, author = {Heuermann, Holger and Schiek, Burkhard}, title = {LNN( Line-Network-Network): The In-Fixture Calibration Procedure}, pages = {149 -- 149}, year = {1993}, language = {en} } @article{HeuermannSchiek1992, author = {Heuermann, Holger and Schiek, Burkhard}, title = {A Generalization of the Txx Network Analyzer Self-Calibration Procedure}, series = {Conference proceedings : monday 24th to thursday 27th august 1992, Helsinki University of Technology, Espoo, Finland ; [the international conference and exhibition designed for the Microwave Community]. Vol. 2}, journal = {Conference proceedings : monday 24th to thursday 27th august 1992, Helsinki University of Technology, Espoo, Finland ; [the international conference and exhibition designed for the Microwave Community]. Vol. 2}, publisher = {Microwave Exhibitions and Publishers}, address = {Tunbridge Wells}, isbn = {0-946821-77-1}, pages = {907 -- 912}, year = {1992}, language = {en} } @article{HeuermannSchiek1994, author = {Heuermann, Holger and Schiek, Burkhard}, title = {Error Corrected Impedance Measurements with a Network Analyzer}, pages = {125 -- 126}, year = {1994}, language = {en} } @article{HeuermannStolleSchiek1995, author = {Heuermann, Holger and Stolle, Reinhard and Schiek, Burkhard}, title = {Novel Algorithms for FMCW Range Finding with Microwaves. Stolle, R.; Heuermann, H.; Schiek, B.}, pages = {129 -- 132}, year = {1995}, language = {en} } @article{HeuermannThalayasingam2009, author = {Heuermann, Holger and Thalayasingam, K.}, title = {Novel vector non-linear measurement system for intermodulation measurements / Thalayasingam, K.; Heuermann, H.}, series = {European Microwave Conference, 2009 : EuMC 2009 ; Sept. 29, 2009 - Oct. 1, 2009, Rome, Italy ; part of European Microwave Week (EuMW) / sponsored by EuMA, European Microwave Association ... Endorsed by IEEE}, journal = {European Microwave Conference, 2009 : EuMC 2009 ; Sept. 29, 2009 - Oct. 1, 2009, Rome, Italy ; part of European Microwave Week (EuMW) / sponsored by EuMA, European Microwave Association ... Endorsed by IEEE}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4244-4748-0}, pages = {926 -- 929}, year = {2009}, language = {en} } @article{Hillgaertner2010, author = {Hillg{\"a}rtner, Michael}, title = {Normative Regulations}, series = {ECPE Cluster Seminar EMC in Hybrid and Electric Vehicles : 18 May 2010, Fraunhofer Institute Erlangen}, journal = {ECPE Cluster Seminar EMC in Hybrid and Electric Vehicles : 18 May 2010, Fraunhofer Institute Erlangen}, publisher = {European Center for Power Electronics}, address = {N{\"u}rnberg}, pages = {1 CD-ROM}, year = {2010}, language = {en} } @article{HillgaertnerKappel2006, author = {Hillg{\"a}rtner, Michael and Kappel, U.}, title = {Radiating Impedance of Mains Cabling During Emissions Testing}, series = {EMC Europe 2006 Barcelona : International Symposium on Electromagnetic Compatibility; September 4 - 8, 2006, Campus Nord, Technical University of Catalonia, Barcelona, Spain / [organized by Technical University of Catalonia (UPC) ... Ed. and publ. by: Ferran Silva ...]. - Vol. 1: Proceedings 1}, journal = {EMC Europe 2006 Barcelona : International Symposium on Electromagnetic Compatibility; September 4 - 8, 2006, Campus Nord, Technical University of Catalonia, Barcelona, Spain / [organized by Technical University of Catalonia (UPC) ... Ed. and publ. by: Ferran Silva ...]. - Vol. 1: Proceedings 1}, address = {Barcelona}, isbn = {84-689-9439-1}, pages = {17 -- 22}, year = {2006}, language = {en} } @article{HillgaertnerPeier2006, author = {Hillg{\"a}rtner, Michael and Peier, Dirk}, title = {Design of a Measurement Setup for the Impedance of Low-Resistance Plate-Conductors in the RF-Range}, series = {Proceedings of the 10th International Conference on Optimization of Electrical and Electronic Equipment, OPTIM '06, Bra\&\#351;ov, May 18 - 20, 2006 / ed. by The Transilvania University of Bra\&\#351;ov, Faculty of Electrical Engineering and Computer Science. [Ed. Mihai Cernat .\&\#804;] . - Vol. 1: Keynote addresses, electrotechnics}, journal = {Proceedings of the 10th International Conference on Optimization of Electrical and Electronic Equipment, OPTIM '06, Bra\&\#351;ov, May 18 - 20, 2006 / ed. by The Transilvania University of Bra\&\#351;ov, Faculty of Electrical Engineering and Computer Science. [Ed. Mihai Cernat .\&\#804;] . - Vol. 1: Keynote addresses, electrotechnics}, address = {Bra\&\#351;ov}, isbn = {978-973-635703-9}, pages = {59 -- 64}, year = {2006}, language = {en} } @article{HillgaertnerStoniesPeieretal.2005, author = {Hillg{\"a}rtner, Michael and Stonies, R. and Peier, D. and Voges, E.}, title = {Design of Low Cost Antennas for Reverberation Chambers}, series = {Proceedings of the 16th International Zurich Symposium on Electromagnetic Compatibility : [EMC Week 2005, Zurich, Switzerland, February 13 - 18 ; technical exhibition on EMC and RF/microwave Measurements and Instrumentation (February 15 - 17)] / [Laboratory for Electromagnetic Fields and Microwave Electronics, Swiss Federal Institute of Technology Zurich]}, journal = {Proceedings of the 16th International Zurich Symposium on Electromagnetic Compatibility : [EMC Week 2005, Zurich, Switzerland, February 13 - 18 ; technical exhibition on EMC and RF/microwave Measurements and Instrumentation (February 15 - 17)] / [Laboratory for Electromagnetic Fields and Microwave Electronics, Swiss Federal Institute of Technology Zurich]}, publisher = {ETH-Zentrum-IFH}, address = {Z{\"u}rich}, isbn = {3-9521199-9-7}, pages = {1 CD-ROM. ; 12 cm}, year = {2005}, language = {en} } @inproceedings{HoegenDonckerBragardetal.2021, author = {Hoegen, Anne von and Doncker, Rik W. De and Bragard, Michael and Hoegen, Svenja von}, title = {Problem-based learning in automation engineering: performing a remote laboratory aession aerving various educational attainments}, series = {2021 IEEE Global Engineering Education Conference (EDUCON)}, booktitle = {2021 IEEE Global Engineering Education Conference (EDUCON)}, publisher = {IEEE}, address = {New York, NY}, doi = {10.1109/EDUCON46332.2021.9453925}, pages = {1605 -- 1614}, year = {2021}, abstract = {During the Covid-19 pandemic, vocational colleges, universities of applied science and technical universities often had to cancel laboratory sessions requiring students' attendance. These above of all are of decisive importance in order to give learners an understanding of theory through practical work.This paper is a contribution to the implementation of distance learning for laboratory work applicable for several upper secondary educational facilities. Its aim is to provide a paradigm for hybrid teaching to analyze and control a non-linear system depicted by a tank model. For this reason, we redesign a full series of laboratory sessions on the basis of various challenges. Thus, it is suitable to serve different reference levels of the European Qualifications Framework (EQF).We present problem-based learning through online platforms to compensate the lack of a laboratory learning environment. With a task deduced from their future profession, we give students the opportunity to develop own solutions in self-defined time intervals. A requirements specification provides the framework conditions in terms of time and content for students having to deal with the challenges of the project in a self-organized manner with regard to inhomogeneous previous knowledge. If the concept of Complete Action is introduced in classes before, they will automatically apply it while executing the project.The goal is to combine students' scientific understanding with a procedural knowledge. We suggest a series of remote laboratory sessions that combine a problem formulation from the subject area of Measurement, Control and Automation Technology with a project assignment that is common in industry by providing extracts from a requirements specification.}, language = {en} } @inproceedings{HoegenDonckerRuetters2020, author = {Hoegen, Anne von and Doncker, Rik W. De and R{\"u}tters, Ren{\´e}}, title = {Teaching Digital Control of Operational Amplifier Processes with a LabVIEW Interface and Embedded Hardware}, series = {2020 23rd International Conference on Electrical Machines and Systems (ICEMS)}, booktitle = {2020 23rd International Conference on Electrical Machines and Systems (ICEMS)}, publisher = {IEEE}, address = {New York, NY}, doi = {10.23919/ICEMS50442.2020.9290928}, pages = {1117 -- 1122}, year = {2020}, abstract = {Control engineering theory is hard to grasp for undergraduates during the first semesters, as it deals with the dynamical behavior of systems also in combination with control strategies on an abstract level. Therefore, operational amplifier (OpAmp) processes are reasonable and very effective systems to connect mathematical description with actual system's behavior. In this paper, we present an experiment for a laboratory session in which an embedded system, driven by a LabVIEW human machine interface (HMI) via USB, controls the analog circuits.With this setup we want to show the possibility of firstly, analyzing a first order process and secondly, designing a P-and PI-controller. Thereby, the theory of control engineering is always applied to the empirical results in order to break down the abstract level for the students.}, language = {en} } @article{HoffmannRohrbachUhletal.2022, author = {Hoffmann, Andreas and Rohrbach, Felix and Uhl, Matthias and Ceblin, Maximilian and Bauer, Thomas and Mallah, Marcel and Jacob, Timo and Heuermann, Holger and Kuehne, Alexander J. C.}, title = {Atmospheric pressure plasma-jet treatment of polyacrylonitrile-nonwovens—Stabilization and roll-to-roll processing}, series = {Journal of Applied Polymer Science}, volume = {139}, journal = {Journal of Applied Polymer Science}, number = {37}, publisher = {Wiley}, issn = {0021-8995 (Print)}, doi = {10.1002/app.52887}, pages = {1 -- 9}, year = {2022}, abstract = {Carbon nanofiber nonwovens represent a powerful class of materials with prospective application in filtration technology or as electrodes with high surface area in batteries, fuel cells, and supercapacitors. While new precursor-to-carbon conversion processes have been explored to overcome productivity restrictions for carbon fiber tows, alternatives for the two-step thermal conversion of polyacrylonitrile precursors into carbon fiber nonwovens are absent. In this work, we develop a continuous roll-to-roll stabilization process using an atmospheric pressure microwave plasma jet. We explore the influence of various plasma-jet parameters on the morphology of the nonwoven and compare the stabilized nonwoven to thermally stabilized samples using scanning electron microscopy, differential scanning calorimetry, and infrared spectroscopy. We show that stabilization with a non-equilibrium plasma-jet can be twice as productive as the conventional thermal stabilization in a convection furnace, while producing electrodes of comparable electrochemical performance.}, language = {en} } @inproceedings{HofmannLimpertMatareetal.2019, author = {Hofmann, Till and Limpert, Nicolas and Matar{\´e}, Victor and Ferrein, Alexander and Lakemeyer, Gerhard}, title = {Winning the RoboCup Logistics League with Fast Navigation, Precise Manipulation, and Robust Goal Reasoning}, series = {RoboCup 2019: Robot World Cup XXIII. RoboCup}, booktitle = {RoboCup 2019: Robot World Cup XXIII. RoboCup}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-35699-6}, doi = {10.1007/978-3-030-35699-6_41}, pages = {504 -- 516}, year = {2019}, language = {en} } @article{HofmannLimpertMatareetal.2018, author = {Hofmann, Till and Limpert, Nicolas and Matar{\´e}, Victor and Sch{\"o}nitz, Sebastian and Niemueller, Tim and Ferrein, Alexander and Lakemeyer, Gerhard}, title = {The Carologistics RoboCup Logistics Team 2018}, year = {2018}, abstract = {The Carologistics team participates in the RoboCup Logistics League for the seventh year. The RCLL requires precise vision, manipulation and path planning, as well as complex high-level decision making and multi-robot coordination. We outline our approach with an emphasis on recent modifications to those components. The team members in 2018 are David Bosen, Christoph Gollok, Mostafa Gomaa, Daniel Habering, Till Hofmann, Nicolas Limpert, Sebastian Sch{\"o}nitz, Morian Sonnet, Carsten Stoffels, and Tarik Viehmann. This paper is based on the last year's team description.}, language = {en} } @inproceedings{HofmannMatareNeumannetal.2018, author = {Hofmann, Till and Matar{\´e}, Victor and Neumann, Tobias and Sch{\"o}nitz, Sebastian and Henke, Christoph and Limpert, Nicolas and Niemueller, Tim and Ferrein, Alexander and Jeschke, Sabina and Lakemeyer, Gerhard}, title = {Enhancing Software and Hardware Reliability for a Successful Participation in the RoboCup Logistics League 2017}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-00308-1}, doi = {10.1007/978-3-030-00308-1_40}, pages = {486 -- 497}, year = {2018}, language = {en} } @inproceedings{HofmannMatareSchifferetal.2018, author = {Hofmann, Till and Matar{\´e}, Victor and Schiffer, Stefan and Ferrein, Alexander and Lakemeyer, Gerhard}, title = {Constraint-based online transformation of abstract plans into executable robot actions}, series = {Proceedings of the 2018 AAAI Spring Symposium on Integrating Representation, Reasoning, Learning, and Execution for Goal Directed Autonomy}, booktitle = {Proceedings of the 2018 AAAI Spring Symposium on Integrating Representation, Reasoning, Learning, and Execution for Goal Directed Autonomy}, pages = {549 -- 553}, year = {2018}, language = {en} } @article{HoltrupSadeghfamHeuermannetal.2014, author = {Holtrup, S. and Sadeghfam, Arash and Heuermann, Holger and Awakowicz, P.}, title = {Characterization and optimization technique for microwave-driven high-intensity discharge lamps using hot S-parameters}, series = {IEEE transactions on microwave theories and techniques}, volume = {62}, journal = {IEEE transactions on microwave theories and techniques}, number = {10}, publisher = {IEEE}, address = {New York}, issn = {0018-9480}, doi = {10.1109/TMTT.2014.2342652}, pages = {2471 -- 2480}, year = {2014}, abstract = {High-intensity discharge lamps can be driven by radio-frequency signals in the ISM frequency band at 2.45 GHz, using a matching network to transform the impedance of the plasma to the source impedance. To achieve an optimal operating condition, a good characterization of the lamp in terms of radio frequency equivalent circuits under operating conditions is necessary, enabling the design of an efficient matching network. This paper presents the characterization technique for such lamps and presents the design of the required matching network. For the characterization, a high-intensity discharge lamp was driven by a monofrequent large signal at 2.45 GHz, whereas a frequency sweep over 300 MHz was performed across this signal to measure so-called small-signal hot S-parameters using a vector network analyzer. These parameters are then used as an equivalent load in a circuit simulator to design an appropriate matching network. Using the measured data as a black-box model in the simulation results in a quick and efficient method to simulate and design efficient matching networks in spite of the complex plasma behavior. Furthermore, photometric analysis of high-intensity discharge lamps are carried out, comparing microwave operation to conventional operation.}, language = {en} } @article{HulseboschGuentherHornetal.2004, author = {Hulsebosch, R. J. and G{\"u}nther, C. and Horn, C. and Holtmanns, S. and Howker, K. and Paterson, K. and Claessens, J. and Schuba, Marko}, title = {Pioneering Advanced Mobile Privacy and Security}, series = {Security for mobility}, journal = {Security for mobility}, editor = {Mitchell, Chris J.}, publisher = {Institution of Electrical Engineers}, address = {London}, isbn = {9781849190886}, doi = {10.1049/PBTE051E_ch}, pages = {383 -- 432}, year = {2004}, language = {en} } @book{Huening2001, author = {H{\"u}ning, Felix}, title = {Magnetische Eigenschaften niederdimensionaler Chrom-, Ruthenium- und Niobhalogenide}, publisher = {Shaker}, address = {Aachen}, isbn = {3-8265-8551-8}, pages = {II, 122 S Ill., graph. Darst.}, year = {2001}, language = {en} } @article{Huening2008, author = {H{\"u}ning, Felix}, title = {Entwicklungstrends bei MOSFETs f{\"u}r den Automobilbereich}, series = {Elektronik-Industrie . 39 (2008), H. 5}, journal = {Elektronik-Industrie . 39 (2008), H. 5}, publisher = {-}, isbn = {0174-5522}, pages = {74 -- 76}, year = {2008}, language = {en} } @article{Huening2009, author = {H{\"u}ning, Felix}, title = {SMD packages for PowerMOSFETs in automotive applications - developments and trends}, series = {Automotive Designline Europe (2009)}, journal = {Automotive Designline Europe (2009)}, publisher = {-}, year = {2009}, language = {en} } @article{Huening2012, author = {H{\"u}ning, Felix}, title = {Using Trench PowerMOSFETs in Linear Mode}, series = {Power Electronics Europe (2012)}, journal = {Power Electronics Europe (2012)}, publisher = {DFA Media}, address = {Tonbridge}, issn = {1748-3530}, pages = {27 -- 29}, year = {2012}, abstract = {If we think about applications for modern Power MOSFETs using trench technology, running them in linear mode may not be top of the priority list. Yet there are multiple uses for Trench Power MOSFETs in linear mode. In fact, even turning the device on and off in switching applications is a form of linear operation. Also, these components can be run in linear mode to protect the device against voltage surges. This article will illustrate the factors that need to be considered for linear operation and show how Trench Power MOSFETs are suited to it.}, language = {en} } @book{Huening2014, author = {H{\"u}ning, Felix}, title = {The fundamentals of electrical engineering for mechatronics}, publisher = {de Gruyter}, address = {Berlin}, isbn = {978-3-11-034991-7 (Druckausg.)}, pages = {IX, 208 S.}, year = {2014}, language = {en} } @inproceedings{Huening2016, author = {H{\"u}ning, Felix}, title = {Power Semiconductors for the automotive 48V board net}, series = {PCIM Europe 2016 Conference Proceedings}, booktitle = {PCIM Europe 2016 Conference Proceedings}, publisher = {VDE Verl.}, address = {Berlin}, isbn = {978-3-8007-4186-1}, pages = {1963 -- 1969}, year = {2016}, language = {en} } @book{Huening2018, author = {H{\"u}ning, Felix}, title = {Embedded Design For IoT With Renesas Synergy}, publisher = {Renesas Electronics}, address = {D{\"u}sseldorf}, pages = {143 S.}, year = {2018}, language = {en} } @inproceedings{Huening2021, author = {H{\"u}ning, Felix}, title = {Sustainable changes beyond covid-19 for a second semester physics course for electrical engineering students}, series = {Blended Learning in Engineering Education: challenging, enlightening - and lasting?}, booktitle = {Blended Learning in Engineering Education: challenging, enlightening - and lasting?}, isbn = {978-2-87352-023-6}, pages = {1424 -- 1428}, year = {2021}, abstract = {The course Physics for Electrical Engineering is part of the curriculum of the bachelor program Electrical Engineering at University of Applied Science Aachen. Before covid-19 the course was conducted in a rather traditional way with all parts (lecture, exercise and lab) face-to-face. This teaching approach changed fundamentally within a week when the covid-19 limitations forced all courses to distance learning. All parts of the course were transformed to pure distance learning including synchronous and asynchronous parts for the lecture, live online-sessions for the exercises and self-paced labs at home. Using these methods, the course was able to impart the required knowledge and competencies. Taking the teacher's observations of the student's learning behaviour and engagement, the formal and informal feedback of the students and the results of the exams into account, the new methods are evaluated with respect to effectiveness, sustainability and suitability for competence transfer. Based on this analysis strong and weak points of the concept and countermeasures to solve the weak points were identified. The analysis further leads to a sustainable teaching approach combining synchronous and asynchronous parts with self-paced learning times that can be used in a very flexible manner for different learning scenarios, pure online, hybrid (mixture of online and presence times) and pure presence teaching.}, language = {en} } @inproceedings{Huening2014, author = {H{\"u}ning, Felix}, title = {Power semiconductors : key components for HEV/EV}, series = {FISITA 2014 World Automotive Congress : 2 - 6 June, Maastricht, the Netherlands International Federation of Automotive Engineering Societies}, booktitle = {FISITA 2014 World Automotive Congress : 2 - 6 June, Maastricht, the Netherlands International Federation of Automotive Engineering Societies}, publisher = {KIVI}, address = {[s.l.]}, pages = {1 USB-Speicherstick}, year = {2014}, language = {en} } @article{HueningBackes2020, author = {H{\"u}ning, Felix and Backes, Andreas}, title = {Direct observation of large Barkhausen jump in thin Vicalloy wires}, series = {IEEE Magnetics Letters}, volume = {11}, journal = {IEEE Magnetics Letters}, number = {Art. 2506504}, publisher = {IEEE}, address = {New York, NY}, isbn = {1949-307X}, doi = {10.1109/LMAG.2020.3046411}, pages = {1 -- 4}, year = {2020}, language = {en} } @article{HueningEifertHandricketal.2006, author = {H{\"u}ning, Felix and Eifert, T. and Handrick, K. and Neuhausen, U.}, title = {Computational Magnetochemistry: Complementary Quantum Mechanical Tools / Eifert, T. ; Handrick, K. ; H{\"u}ning, F. ; Neuhausen, U. ; Schilder, H. ; Lueken, H.}, series = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie (ZAAC) - Journal of Inorganic and General Chemistry . 632 (2006), H. 4}, journal = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie (ZAAC) - Journal of Inorganic and General Chemistry . 632 (2006), H. 4}, publisher = {-}, isbn = {1521-3749}, pages = {521 -- 529}, year = {2006}, language = {en} } @article{HueningEifertHandricketal.2006, author = {H{\"u}ning, Felix and Eifert, T. and Handrick, K. and Neuhausen, U.}, title = {Computational Magnetochemistry: Complementary Quantum Mechanical Tools / Eifert, T. ; Handrick, K. ; H{\"u}ning, F. ; Neuhausen, U. ; Schilder, H. ; Lueken, H.}, series = {20 Jahre Wilhelm-Klemm-Stiftung / Kuratorium der Wilhelm-Klemm-Stiftung (Hrsg.)}, journal = {20 Jahre Wilhelm-Klemm-Stiftung / Kuratorium der Wilhelm-Klemm-Stiftung (Hrsg.)}, publisher = {Shaker}, address = {Aachen}, isbn = {978-3-8322-5520-6}, pages = {193ff}, year = {2006}, language = {en} } @article{HueningEifertLuekenetal.2002, author = {H{\"u}ning, Felix and Eifert, T. and Lueken, H. and Schmidt, P.}, title = {High-temperature series expansion of the magnetic susceptibility of extended magnetic systems in a complete computer implementation / Eifert, T. ; H{\"u}ning, F. ; Lueken, H. ; Schmidt, P. ; Thiele, G.}, series = {Chemical Physics Letters. 364 (2002), H. 1-2}, journal = {Chemical Physics Letters. 364 (2002), H. 1-2}, publisher = {-}, isbn = {0009-2614}, pages = {69 -- 74}, year = {2002}, language = {en} } @article{HueningHeuermannWache2018, author = {H{\"u}ning, Felix and Heuermann, Holger and Wache, Franz-Josef}, title = {Wireless CAN without WLAN or Bluetooth}, series = {CAN Newsletter}, journal = {CAN Newsletter}, number = {December 2018}, pages = {44 -- 46}, year = {2018}, abstract = {In two developed concepts, dual-mode radio enables CAN participants to be integrated wirelessly into a CAN network. Constructed from a few components, a protocol-free, real-time transmission and thus transparent integration into CAN is provided.}, language = {en} } @article{HueningHeuermannWacheetal.2018, author = {H{\"u}ning, Felix and Heuermann, Holger and Wache, Franz-Josef and Jajo, Rami Audisho}, title = {A new wireless sensor interface using dual-mode radio}, series = {Journal of Sensors and Sensor Systems : JSSS}, volume = {Volume 7}, journal = {Journal of Sensors and Sensor Systems : JSSS}, number = {2}, publisher = {Copernicus Publ.}, address = {G{\"o}ttingen}, doi = {10.5194/jsss-7-507-2018}, pages = {507 -- 515}, year = {2018}, abstract = {The integration of sensors is one of the major tasks in embedded, control and "internet of things" (IoT) applications. For the integration mainly digital interfaces are used, starting from rather simple pulse-width modulation (PWM) interface to more complex interfaces like CAN (Controller Area Network). Even though these interfaces are tethered by definition, a wireless realization is highly welcome in many applications to reduce cable and connector cost, increase the flexibility and realize new emerging applications like wireless control systems. Currently used wireless solutions like Bluetooth, WirelessHART or IO-Link Wireless use dedicated communication standards and corresponding higher protocol layers to realize the wireless communication. Due to the complexity of the communication and the protocol handling, additional latency and jitter are introduced to the data communication that can meet the requirements for many applications. Even though tunnelling of other bus data like CAN data is generally also possible the latency and jitter prevent the tunnelling from being transparent for the bus system. Therefore a new basic technology based on dual-mode radio is used to realize a wireless communication on the physical layer only, enabling a reliable and real-time data transfer. As this system operates on the physical layer it is independent of any higher layers of the OSI (open systems interconnection) model. Hence it can be used for several different communication systems to replace the tethered physical layer. A prototype is developed and tested for real-time wireless PWM, SENT (single-edge nibble transmission) and CAN data transfer with very low latency and jitter.}, language = {en} } @article{HueningJaekelFrancoisetal.1996, author = {H{\"u}ning, Felix and Jaekel, C. and Francois, I. and Kyas, G.}, title = {Microwave surface impedance measurements on high-Tc superconductors / Jaekel, C. ; Francois, I. ; Kyas, G. ; H{\"u}ning, F. ; Roskos, H. G. ; Borghs, G. ; Kurz, H.}, series = {Czechoslovak Journal of Physics. 46 (1996), H. Suppl. 2}, journal = {Czechoslovak Journal of Physics. 46 (1996), H. Suppl. 2}, number = {46}, publisher = {Springer Science+Business Media}, address = {Dordrecht}, isbn = {1572-9486}, pages = {1117 -- 1118}, year = {1996}, language = {en} } @article{HueningLeineweberJacobsetal.1999, author = {H{\"u}ning, Felix and Leineweber, A. and Jacobs, H. and Lueken, H.}, title = {ε-Fe3N: magnetic structure, magnetization and temperature dependent disorder of nitrogen / Leineweber, A. ; Jacobs, H. ; H{\"u}ning, F. ; Lueken, H. ; Schilder, H. ; Kockelmann, W.}, series = {Journal of Alloys and Compounds. 288 (1999), H. 1-2}, volume = {288}, journal = {Journal of Alloys and Compounds. 288 (1999), H. 1-2}, number = {1-2}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {1873-4669}, pages = {79 -- 87}, year = {1999}, abstract = {ε-Fe3N has been investigated by time-of-flight neutron diffraction (temperature range 4.2-618 K) and SQUID magnetometry (2-700 K, B≤5 T). A ferromagnetic spin structure is observed with magnetic moments oriented perpendicular to the c-axis of the hexagonal nuclear structure. The magnetic saturation moment of iron is 2.2 μB at 4.2 K from neutron diffraction and 2.0 μB from magnetic measurements and decreases in a Brillouin-like manner on heating to TC=575 K. Above 450 K an increasing but reversible disorder of the nitrogen partial structure is observed.}, language = {en} } @article{HueningLeineweberJacobsetal.2001, author = {H{\"u}ning, Felix and Leineweber, A. and Jacobs, H. and Lueken, H.}, title = {Nitrogen Ordering and ferromagnetic properties of -Fe3N1+x (0.10  x  0.39) and -Fe3(N0.80C0.20)1.38 / Leineweber, A. ; Jacobs, H. ; H{\"u}ning, F. ; Lueken, H. ; Kockelmann, W.}, series = {Journal of Alloys and Compounds. 316 (2001), H. 1-2}, journal = {Journal of Alloys and Compounds. 316 (2001), H. 1-2}, publisher = {-}, isbn = {1873-4669}, pages = {21 -- 38}, year = {2001}, language = {en} } @article{HueningLukenSchilderetal.2001, author = {H{\"u}ning, Felix and Luken, Heiko and Schilder, Herbert and Eifert, Thomas}, title = {Magnetochemistry: Compounds and Concepts / Lueken, Heiko ; Schilder, Herbert ; Eifert, Thomas ; Handrick, Klaus ; H{\"u}ning, Felix}, series = {Advances in Solid State Physics. 201 (2001)}, journal = {Advances in Solid State Physics. 201 (2001)}, publisher = {-}, pages = {515 -- 532}, year = {2001}, language = {en} } @inproceedings{HueningMund2023, author = {H{\"u}ning, Felix and Mund, Cindy}, title = {Integration of agile development in standard labs}, series = {51st Annual Conference of the European Society for Engineering Education (SEFI)}, booktitle = {51st Annual Conference of the European Society for Engineering Education (SEFI)}, doi = {10.21427/NK4Z-WS73}, pages = {11 Seiten}, year = {2023}, abstract = {In addition to the technical content, modern courses at university should also teach professional skills to enhance the competencies of students towards their future work. The competency driven approach including technical as well as professional skills makes it necessary to find a suitable way for the integration into the corresponding module in a scalable and flexible manner. Agile development, for example, is essential for the development of modern systems and applications and makes use of dedicated professional skills of the team members, like structured group dynamics and communication, to enable the fast and reliable development. This paper presents an easy to integrate and flexible approach to integrate Scrum, an agile development method, into the lab of an existing module. Due to the different role models of Scrum the students have an individual learning success, gain valuable insight into modern system development and strengthen their communication and organization skills. The approach is implemented and evaluated in the module Vehicle Systems, but it can be transferred easily to other technical courses as well. The evaluation of the implementation considers feedback of all stakeholders, students, supervisor and lecturers, and monitors the observations during project lifetime.}, language = {en} } @article{HueningSpartaRedhammeretal.2001, author = {H{\"u}ning, Felix and Sparta, K. and Redhammer, G. J. and Roussel, P.}, title = {Structural Phase Transition in the 2D Spin Dimer Compound SrCu2(BO3)2 / Sparta, K. ; Redhammer, G. J. ; Roussel, P. ; Heger, G. ; Roth, G. ; Ionescu, A. Lemmens, P. ; Grove, M. ; G{\"u}ntherrodt, G. ; H{\"u}ning, F. ; Lueken, H. ; Kageyama, H. ; Onizuka, K ; Ueda}, series = {The European Physical Journal B - Condensed Matter and Complex Systems. 19 (2001), H. 4}, journal = {The European Physical Journal B - Condensed Matter and Complex Systems. 19 (2001), H. 4}, publisher = {-}, isbn = {1434-6036}, pages = {507 -- 516}, year = {2001}, language = {en} } @inproceedings{HueningStuettgen2021, author = {H{\"u}ning, Felix and St{\"u}ttgen, Marcel}, title = {Work in Progress: Interdisciplinary projects in times of COVID-19 crisis - challenges, risks and chances}, series = {2021 IEEE Global Engineering Education Conference (EDUCON)}, booktitle = {2021 IEEE Global Engineering Education Conference (EDUCON)}, publisher = {IEEE}, address = {New York, NY}, doi = {10.1109/EDUCON46332.2021.9454006}, pages = {1175 -- 1179}, year = {2021}, abstract = {Project work and inter disciplinarity are integral parts of today's engineering work. It is therefore important to incorporate these aspects into the curriculum of academic studies of engineering. At the faculty of Electrical Engineering and Information Technology an interdisciplinary project is part of the bachelor program to address these topics. Since the summer term 2020 most courses changed to online mode during the Covid-19 crisis including the interdisciplinary projects. This online mode introduces additional challenges to the execution of the projects, both for the students as well as for the lecture. The challenges, but also the risks and chances of this kind of project courses are subject of this paper, based on five different interdisciplinary projects}, language = {en} } @inproceedings{HueningWacheMagiera2021, author = {H{\"u}ning, Felix and Wache, Franz-Josef and Magiera, David}, title = {Redundant bus systems using dual-mode radio}, series = {Proceedings of Sixth International Congress on Information and Communication Technology}, booktitle = {Proceedings of Sixth International Congress on Information and Communication Technology}, publisher = {Springer}, address = {Singapore}, isbn = {978-981-16-2379-0}, doi = {10.1007/978-981-16-2380-6_73}, pages = {835 -- 842}, year = {2021}, abstract = {Communication via serial bus systems, like CAN, plays an important role for all kinds of embedded electronic and mechatronic systems. To cope up with the requirements for functional safety of safety-critical applications, there is a need to enhance the safety features of the communication systems. One measure to achieve a more robust communication is to add redundant data transmission path to the applications. In general, the communication of real-time embedded systems like automotive applications is tethered, and the redundant data transmission lines are also tethered, increasing the size of the wiring harness and the weight of the system. A radio link is preferred as a redundant transmission line as it uses a complementary transmission medium compared to the wired solution and in addition reduces wiring harness size and weight. Standard wireless links like Wi-Fi or Bluetooth cannot meet the requirements for real-time capability with regard to bus communication. Using the new dual-mode radio enables a redundant transmission line meeting all requirements with regard to real-time capability, robustness and transparency for the data bus. In addition, it provides a complementary transmission medium with regard to commonly used tethered links. A CAN bus system is used to demonstrate the redundant data transfer via tethered and wireless CAN.}, language = {en} } @article{HueningWilkeNakielskietal.1997, author = {H{\"u}ning, Felix and Wilke, I. and Nakielski, G. and Kotzler, J.}, title = {Dynamic conductivity of YBCO thin films from low to very high frequencies / Wilke, I. ; Nakielski, G. ; Kotzler, J. ; Subke, K. O. ; Jaekel, C. ; H{\"u}ning, F. ; Roskos, H. G. ; Kurz, Heinrich}, series = {Applied superconductivity 1997 : proceedings of EUCAS 1997, the Third European Conference on Applied Superconductivity, held in the Netherlands, 30 June - 3 July 1997 / ed. by H. Rogalla}, journal = {Applied superconductivity 1997 : proceedings of EUCAS 1997, the Third European Conference on Applied Superconductivity, held in the Netherlands, 30 June - 3 July 1997 / ed. by H. Rogalla}, publisher = {IOP}, address = {Bristol}, isbn = {0-7503-0487-1}, pages = {121 -- 124}, year = {1997}, language = {en} } @incollection{IbanezSanchezWolf2020, author = {Ibanez-Sanchez, Gema and Wolf, Martin R.}, title = {Interactive Process Mining-Induced Change Management Methodology for Healthcare}, series = {Interactive Process Mining in Healthcare}, booktitle = {Interactive Process Mining in Healthcare}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-53993-1 (Online)}, doi = {10.1007/978-3-030-53993-1_16}, pages = {267 -- 293}, year = {2020}, abstract = {The adoption of the Digital Health Transformation is a tremendous paradigm change in health organizations, which is not a trivial process in reality. For that reason, in this chapter, it is proposed a methodology with the objective to generate a changing culture in healthcare organisations. Such a change culture is essential for the successful implementation of any supporting methods like Interactive Process Mining. It needs to incorporate (mostly) new ways of team-based and evidence-based approaches for solving structural problems in a digital healthcare environment.}, language = {en} } @article{JensKaldenhoffKirschnerHermannsetal.2014, author = {Jens, Otto and Kaldenhoff, E. and Kirschner-Hermanns, R. and M{\"u}hl, Thomas and Klinge, Uwe}, title = {Elongation of textile pelvic floor implants under load is related to complete loss of effective porosity, thereby favoring incorporation in scar plates}, series = {Journal of biomedical materials research. Part A}, volume = {102}, journal = {Journal of biomedical materials research. Part A}, number = {4}, publisher = {Wiley}, address = {New York}, issn = {1552-4965}, doi = {10.1002/jbm.a.34767}, pages = {1079 -- 1084}, year = {2014}, abstract = {Use of textile structures for reinforcement of pelvic floor structures has to consider mechanical forces to the implant, which are quite different to the tension free conditions of the abdominal wall. Thus, biomechanical analysis of textile devices has to include the impact of strain on stretchability and effective porosity. Prolift® and Prolift + M®, developed for tension free conditions, were tested by measuring stretchability and effective porosity applying mechanical strain. For comparison, we used Dynamesh-PR4®, which was designed for pelvic floor repair to withstand mechanical strain. Prolift® at rest showed moderate porosity with little stretchability but complete loss of effective porosity at strain of 4.9 N/cm. Prolift + M® revealed an increased porosity at rest, but at strain showed high stretchability, with subsequent loss of effective porosity at strain of 2.5 N/cm. Dynamesh PR4® preserved its high porosity even under strain, but as consequence of limited stretchability. Though in tension free conditions Prolift® and Prolift + M® can be considered as large pore class I meshes, application of mechanical strain rapidly lead to collapse of pores. The loss of porosity at mechanical stress can be prevented by constructions with high structural stability. Assessment of porosity under strain was found helpful to define requirements for pelvic floor devices. Clinical studies have to prove whether devices with high porosity as well as high structural stability can improve the patients' outcome.}, language = {en} } @inproceedings{KirschMatareFerreinetal.2020, author = {Kirsch, Maximilian and Matar{\´e}, Victor and Ferrein, Alexander and Schiffer, Stefan}, title = {Integrating golog++ and ROS for Practical and Portable High-level Control}, series = {Proceedings of the 12th International Conference on Agents and Artificial Intelligence - Volume 2}, booktitle = {Proceedings of the 12th International Conference on Agents and Artificial Intelligence - Volume 2}, publisher = {SciTePress}, address = {Set{\´u}bal, Portugal}, doi = {10.5220/0008984406920699}, pages = {692 -- 699}, year = {2020}, abstract = {The field of Cognitive Robotics aims at intelligent decision making of autonomous robots. It has matured over the last 25 or so years quite a bit. That is, a number of high-level control languages and architectures have emerged from the field. One concern in this regard is the action language GOLOG. GOLOG has been used in a rather large number of applications as a high-level control language ranging from intelligent service robots to soccer robots. For the lower level robot software, the Robot Operating System (ROS) has been around for more than a decade now and it has developed into the standard middleware for robot applications. ROS provides a large number of packages for standard tasks in robotics like localisation, navigation, and object recognition. Interestingly enough, only little work within ROS has gone into the high-level control of robots. In this paper, we describe our approach to marry the GOLOG action language with ROS. In particular, we present our architecture on inte grating golog++, which is based on the GOLOG dialect Readylog, with the Robot Operating System. With an example application on the Pepper service robot, we show how primitive actions can be easily mapped to the ROS ActionLib framework and present our control architecture in detail.}, language = {en} } @article{KlingeOttoMuehl2015, author = {Klinge, Uwe and Otto, Jens and M{\"u}hl, Thomas}, title = {High Structural Stability of Textile Implants Prevents Pore Collapse and Preserves Effective Porosity at Strain}, series = {BioMed Research International}, volume = {2015}, journal = {BioMed Research International}, issn = {2314-6133 (Print)}, doi = {10.1155/2015/953209}, pages = {7 pages}, year = {2015}, language = {en} } @article{KlompBitzHeerschapetal.2009, author = {Klomp, D. W. J. and Bitz, Andreas and Heerschap, A. and Scheenen, T. W. J.}, title = {Proton spectroscopic imaging of the human prostate at 7 T}, series = {NMR in Biomedicine}, volume = {22}, journal = {NMR in Biomedicine}, number = {5}, issn = {1099-1492}, doi = {10.1002/nbm.1360}, pages = {495 -- 501}, year = {2009}, language = {en} } @article{KobFrauenrath2009, author = {Kob, Malte and Frauenrath, Tobias}, title = {A system for parallel measurement of glottis opening and larynx position}, series = {Biomedical Signal Processing and Control}, volume = {4}, journal = {Biomedical Signal Processing and Control}, number = {3}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1746-8108}, doi = {10.1016/j.bspc.2009.03.004}, pages = {221 -- 228}, year = {2009}, abstract = {The simultaneous assessment of glottal dynamics and larynx position can be beneficial for the diagnosis of disordered voice or speech production and swallowing. Up to now, methods either concentrate on assessment of the glottis opening using optical, acoustical or electrical (electroglottography, EGG) methods, or on visualisation of the larynx position using ultrasound, computer tomography or magnetic resonance imaging techniques. The method presented here makes use of a time-multiplex measurement approach of space-resolved transfer impedances through the larynx. The fast sequence of measurements allows a quasi simultaneous assessment of both larynx position and EGG signal using up to 32 transmit-receive signal paths. The system assesses the dynamic opening status of the glottis as well as the vertical and back/forward motion of the larynx. Two electrode-arrays are used for the measurement of the electrical transfer impedance through the neck in different directions. From the acquired data the global and individual conductivity is calculated as well as a 2D point spatial representation of the minimum impedance. The position information is shown together with classical EGG signals allowing a synchronous visual assessment of glottal area and larynx position. A first application to singing voice analysis is presented that indicate a high potential of the method for use as a non-invasive tool in the diagnosis of voice, speech, and swallowing disorders.}, language = {en} } @article{KobusBitzUdenetal.2012, author = {Kobus, Thiele and Bitz, Andreas and Uden, Mark J. van and Lagemaat, Miram W. and Rothgang, Eva and Orzada, Stephan and Heerschap, Arend and Scheenen, Tom W. J.}, title = {In vivo 31P MR spectroscopic imaging of the human prostate at 7 T: safety and feasibility}, series = {Magnetic Resonance in Medicine}, volume = {68}, journal = {Magnetic Resonance in Medicine}, number = {6}, publisher = {Wiley-Liss}, address = {New York}, issn = {1522-2594}, doi = {10.1002/mrm.24175}, pages = {1683 -- 1695}, year = {2012}, abstract = {31P MR spectroscopic imaging of the human prostate provides information about phosphorylated metabolites that could be used for prostate cancer characterization. The sensitivity of a magnetic field strength of 7 T might enable 3D 31P MR spectroscopic imaging with relevant spatial resolution in a clinically acceptable measurement time. To this end, a 31P endorectal coil was developed and combined with an eight-channel 1H body-array coil to relate metabolic information to anatomical location. An extensive safety validation was performed to evaluate the specific absorption rate, the radiofrequency field distribution, and the temperature distribution of both coils. This validation consisted of detailed Finite Integration Technique simulations, confirmed by MR thermometry and Burn:x-wiley:07403194:media:MRM24175:tex2gif-stack-1 measurements in a phantom and in vivo temperature measurements. The safety studies demonstrated that the presence of the 31P endorectal coil had no influence on the specific absorption rate levels and temperature distribution of the external eight-channel 1H array coil. To stay within a 10 g averaged local specific absorption rate of 10 W/kg, a maximum time-averaged input power of 33 W for the 1H array coil was allowed. For transmitting with the 31P endorectal coil, our safety limit of less than 1°C temperature increase in vivo during a 15-min MR spectroscopic imaging experiment was reached at a time-averaged input power of 1.9 W. With this power setting, a second in vivo measurement was performed on a healthy volunteer. Using adiabatic excitation, 3D 31P MR spectroscopic imaging produced spectra from the entire prostate in 18 min with a spatial resolution of 4 cm3. The spectral resolution enabled the separate detection of phosphocholine, phosphoethanolamine, inorganic phosphate, and other metabolites that could play an important role in the characterization of prostate cancer.}, language = {en} } @article{KowalewskiBragardHueningetal.2023, author = {Kowalewski, Paul and Bragard, Michael and H{\"u}ning, Felix and De Doncker, Rik W.}, title = {An inexpensive Wiegand-sensor-based rotary encoder without rotating magnets for use in electrical drives}, series = {IEEE Transactions on Instrumentation and Measurement}, volume = {72}, journal = {IEEE Transactions on Instrumentation and Measurement}, publisher = {IEEE}, address = {New York}, issn = {0018-9456 (Print)}, doi = {10.1109/TIM.2023.3326166}, pages = {10 Seiten}, year = {2023}, abstract = {This paper introduces an inexpensive Wiegand-sensor-based rotary encoder that avoids rotating magnets and is suitable for electrical-drive applications. So far, Wiegand-sensor-based encoders usually include a magnetic pole wheel with rotating permanent magnets. These encoders combine the disadvantages of an increased magnet demand and a limited maximal speed due to the centripetal force acting on the rotating magnets. The proposed approach reduces the total demand of permanent magnets drastically. Moreover, the rotating part is manufacturable from a single piece of steel, which makes it very robust and cheap. This work presents the theoretical operating principle of the proposed approach and validates its benefits on a hardware prototype. The presented proof-of-concept prototype achieves a mechanical resolution of 4.5 ° by using only 4 permanent magnets, 2Wiegand sensors and a rotating steel gear wheel with 20 teeth.}, language = {en} } @article{KraffBitzBreyeretal.2011, author = {Kraff, Oliver and Bitz, Andreas and Breyer, Tobias and Kruszona, Stefan and Maderwald, Stefan and Brote, Irina and Gizewski, Elke R. and Ladd, Mark E. and Quick, Harald H.}, title = {A transmit/receive radiofrequency array for imaging the carotid arteries at 7 Tesla: coil design and first in vivo results}, series = {Investigative Radiology}, volume = {46}, journal = {Investigative Radiology}, number = {4}, publisher = {Wolters Kluwer}, address = {K{\"o}ln}, issn = {1536-0210}, doi = {10.1097/RLI.0b013e318206cee4}, pages = {246 -- 254}, year = {2011}, abstract = {Objective: To develop a transmit/receive radiofrequency (RF) array for magnetic resonance imaging (MRI) of the carotid arteries at 7 T. The prototype is characterized in numerical simulations and bench measurements, and the feasibility of plaque imaging at 7 T is demonstrated in first in vivo images. Materials and Methods: The RF phased array coil consists of 8 surface loop coils. To allow imaging of both sides of the neck, the RF array is divided into 2 coil clusters, each with 4 overlapping loop elements. For safety validation, numerical computations of the RF field distribution and the corresponding specific absorption rate were performed on the basis of a heterogeneous human body model. To validate the coil model, maps of the transmit B1+ field were compared between simulation and measurement. In vivo images of a healthy volunteer and a patient (ulcerating plaque and a 50\% stenosis of the right internal carotid artery) were acquired using a 3-dimensional FLASH sequence with a high isotropic spatial resolution of 0.54 mm as well as using pulse-triggered proton density (PD)/T2-weighted turbo spin echo sequences. Results: Measurements of the S-parameters yielded a reflection and isolation of the coil elements of better than -18 and -13 dB, respectively. Measurements of the g-factor indicated good image quality for parallel imaging acceleration factors up to 2.4. A similar distribution and a very good match of the absolute values were found between the measured and simulated B1+ transmit RF field for the validation of the coil model. In vivo images revealed good signal excitation of both sides of the neck and a high vessel-to-background image contrast for the noncontrast-enhanced 3-dimensional FLASH sequence. Imaging at 7 T could depict the extent of stenosis, and revealed the disruption and ulcer of the plaque. Conclusions: This study demonstrates that 2 four-channel transmit/receive RF arrays for each side of the neck is a suitable concept for in vivo MRI of the carotid arteries at 7 Tesla. Further studies are needed to explore and exploit the full potential of 7 T high-field MRI for carotid atherosclerotic plaque imaging.}, language = {en} } @article{KraffBitzDammannetal.2010, author = {Kraff, Oliver and Bitz, Andreas and Dammann, Philipp and Ladd, Susanne C. and Ladd, Mark E. and Quick, Harald H.}, title = {An eight-channel transmit/receive multipurpose coil for musculoskeletal MR imaging at 7 T}, series = {Medical Physics}, volume = {37}, journal = {Medical Physics}, number = {12}, publisher = {Wiley}, address = {Hoboken, NJ}, issn = {2473-4209}, doi = {10.1118/1.3517176}, pages = {6368 -- 6376}, year = {2010}, abstract = {Purpose: MRI plays a leading diagnostic role in assessing the musculoskeletal (MSK) system and is well established for most questions at clinically used field strengths (up to 3 T). However, there are still limitations in imaging early stages of cartilage degeneration, very fine tendons and ligaments, or in locating nerve lesions, for example. 7 T MRI of the knee has already received increasing attention in the current published literature, but there is a strong need to develop new radiofrequency (RF) coils to assess more regions of the MSK system. In this work, an eight-channel transmit/receive RF array was built as a multipurpose coil for imaging some of the thus far neglected regions. An extensive coil characterization protocol and first in vivo results of the human wrist, shoulder, elbow, knee, and ankle imaged at 7 T will be presented. Methods: Eight surface loop coils with a dimension ofurn:x-wiley:00942405:media:mp7176:mp7176-math-0001 were machined from FR4 circuit board material. To facilitate easy positioning, two coil clusters, each with four loop elements, were combined to one RF transmit/receive array. An overlapped and shifted arrangement of the coil elements was chosen to reduce the mutual inductance between neighboring coils. A phantom made of body-simulating liquid was used for tuning and matching on the bench. Afterward, the S-parameters were verified on a human wrist, elbow, and shoulder. For safety validation, a detailed compliance test was performed including full wave simulations of the RF field distribution and the corresponding specific absorption rate (SAR) for all joints. In vivo images of four volunteers were assessed with gradient echo and spin echo sequences modified to obtain optimal image contrast, full anatomic coverage, and the highest spatial resolution within a reasonable acquisition time. The performance of the RF coil was additionally evaluated by in vivo B1 mapping. Results: A comparison of B1 per unit power, flip angle distribution, and anatomic images showed a fairly homogeneous excitation for the smaller joints (elbow, wrist, and ankle), while for the larger joints, the shoulder and especially the knee, B1 inhomogeneities and limited penetration depth were more pronounced. However, the greater part of the shoulder joint could be imaged.In vivo images rendered very fine anatomic details such as fascicles of the median nerve and the branching of the nerve bundles. High-resolution images of cartilage, labrum, and tendons could be acquired. Additionally, turbo spin echo (TSE) and inversion recovery sequences performed very well. Conclusions: This study demonstrates that the concept of two four-channel transmit/receive RF arrays can be used as a multipurpose coil for high-resolutionin vivo MR imaging of the musculoskeletal system at 7 T. Not only gradient echo but also typical clinical and SAR-intensive sequences such as STIR and TSE performed well. Imaging of small structures and peripheral nerves could in particular benefit from this technique.}, language = {en} }