TY  - JOUR
A1  - Hüning, Felix
T1  - Using Trench PowerMOSFETs in Linear Mode
JF  - Power Electronics Europe (2012)
N2  - 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.
Y1  - 2012
SN  - 1748-3530
SP  - 27
EP  - 29
PB  - DFA Media
CY  - Tonbridge
ER  - 
TY  - JOUR
A1  - Yazdanbakhsh, Pedram
A1  - Solbach, Klaus
A1  - Bitz, Andreas
T1  - Variable power combiner for RF mode shimming in 7-T MR imaging
JF  - IEEE Transaction on Biomedical Engineering
N2  - This contribution discusses the utilization of RF power in an MRI system with RF mode shimming which enables the superposition of circularly polarized modes of a transmit RF coil array driven by a Butler matrix. Since the required power for the individual modes can vary widely, mode-shimming can result in a significant underutilization of the total available RF power. A variable power combiner (VPC) is proposed to improve the power utilization: it can be realized as a reconfiguration of the MRI transmit system by the inclusion of one additional matrix network which receives the power from all transmit amplifiers at its input ports and provides any desired (combined) power distribution at its output ports by controlling the phase and amplitude of the amplifiers’ input signals. The power distribution at the output ports of the VPC is then fed into the “mode” ports of the coil array Butler matrix in order to superimpose the spatial modes at the highest achievable power utilization. The VPC configuration is compared to the standard configuration of the transmit chain of our MRI system with 8 transmit channels and 16 coils. In realistic scenarios, improved power utilization was achieved from 17% to 60% and from 14% to 55% for an elliptical phantom and a region of interest in the abdomen, respectively, and an increase of the power utilization of 1 dB for a region of interest in the upper leg. In general, it is found that the VPC allows significant improvement in power utilization when the shimming solution demands only a few modes to be energized, while the technique can yield loss in power utilization in cases with many modes required at high power level.
Y1  - 2012
U6  - http://dx.doi.org/10.1109/TBME.2012.2205926
SN  - 1558-2531
VL  - 59
IS  - 9
SP  - 2549
EP  - 2557
PB  - IEEE
CY  - New York
ER  - 
TY  - BOOK
A1  - Digel, Ilya
A1  - Zhubanova, Azhar Ahmetovna
A1  - Akimbekov, Nuraly Shardarbekovich
T1  - Visual Virology
Y1  - 2012
SN  - 978-601-247-298-1
N1  - Text kasachisch, russisch, englisch
CY  - Almaty
ER  - 
TY  - CHAP
A1  - Fredebeul-Krein, Markus
A1  - Steingröver, Markus
T1  - Wholesale Broadband Access to IPTV in an NGA environment : how to deal with it from a regulatory perspective?
Y1  - 2012
N1  - Regional ITS Conference of the international Telecommunications Society , February 22-24, 2012 New Delhi, India
SP  - 1
EP  - 16
ER  -