An X-Band High-Power GaN HEMT SPDT Switch With LC Resonant Isolation and Parallel Inductor-Assisted Power Distribution

초록

This article presents the design, fabrication, and experimental validation of an X-band (8-12 GHz) high-power single-pole double-throw (SPDT) RF switch based on a 150-nm gallium nitride high electron mobility transistor (GaN HEMT) process. The proposed switch architecture incorporates parallel LC resonant circuits and a traveling-wave transistor network to simultaneously achieve low insertion loss, high Tx/Rx isolation, and enhanced power handling capability in a compact footprint. To overcome the limitations of conventional quarter wavelength-based designs, a novel power distribution technique using parallel inductors is introduced, enabling dynamic current sharing under high-power operation. The fabricated chip, including test pads, occupies an area of 2.70 x 0.74 mm2. Measured results demonstrate a return loss greater than 13.3 dB across the target frequency band, with insertion losses of less than 0.9 dB in Tx mode and 1.2 dB in Rx mode. Isolation performance exceeds 37.2 dB (Tx) and 27.8 dB (Rx), while the input 1-dB compression point (IP1dB) reaches 41.7 dBm in Rx mode and exceeds 45.5 dBm in Tx mode. These results confirm the effectiveness of the proposed resonant isolation and power distribution strategy, making the switch promising candidate for compact, high-power RF systems X-band applications.

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