GaN HEMT decoupling circuit for MR receive coil

Motivation: Low-power circuits are key to miniaturizing MR receive coil electronics for improved flexibility and reduced weight. GaN HEMT decoupling circuits offer a promising alternative to PIN diodes. Goal(s): This research evaluates GaN HEMT decoupling circuits, comparing them to traditional PIN diode circuits, while assessing potential risks and impacts on coil performance. Approach: Decoupling performance of GaN HEMTs from two manufacturers was tested under RF power, along with Hall Effect and switching time evaluations in MRI systems. Results: Current GaN HEMTs can't handle high RF currents like PIN diodes. A parallel passive diode is needed for protection and enhanced decoupling performance. Impact: This research identifies the limitations of existing GaN HEMTs in MR receive coil decoupling circuits. It proposes a hybrid decoupling circuit that integrates GaN HEMTs with passive switching diodes to achieve low-power decoupling in receive coils.