Depletion-Mode GaN HEMT Q-Spoil Switches for MRI Coils

作者：Lu Jonathan Y^*; Grafendorfer Thomas; Zhang Tao; Vasanawala Shreyas; Robb Fraser; Pauly John M; Scott Greig C

来源：IEEE Transactions on Medical Imaging, 2016, 35(12): 2558-2567.

DOI：10.1109/TMI.2016.2586053

• Q-spoiling
• GaN HEMT
• depletion mode
• receive coils

Q-spoiling is the process of decoupling an MRI receive coil to protect the equipment and patient. Conventionally, Q-spoiling is performed using a PIN diode switch that draws significant current. In this work, a Q-spoiling technique using a depletion-mode Gallium Nitride HEMT device was developed for coil detuning at both 1.5 T and 3 T MRI. The circuits with conventional PIN diode Q-spoiling and the GaN HEMT device were implemented on surface coils. SNR was measured and compared for all surfaces coils. At both 1.5 T and 3 T, comparable SNR was achieved for all coils with the proposed technique and conventional Q-spoiling. The GaN HEMT device has significantly reduced the required power for Q-spoiling. The GaN HEMT device also provides useful safety features by detuning the coil when unpowered.

• 出版日期2016-12