X‐band high isolation single pole double throw switch based on resonant concept

Abstract

AbstractUtilizing the 0.25 μm GaN HEMT process, a high‐isolation single pole double throw (SPDT) RF switch has been meticulously designed for the X‐band. The circuit topology employs a series‐shunt configuration to prevent signal leakage, thereby enhancing chip isolation. By incorporating series transistors and shunt inductors, LC resonance is achieved, significantly boosting isolation performance. To optimize port matching and ensure both heightened isolation and minimized insertion loss, inductors are strategically integrated into each port. The inclusion of these lumped inductors contributes significantly to reducing the chip's footprint. Die measurement results demonstrate that across the 8–12 GHz frequency spectrum, insertion loss remains below 1.1 dB, with isolation exceeding 36 dB. Remarkably, at 10.5 GHz, isolation peaks at an impressive 52 dB. Moreover, return loss surpasses 12 dB, and the 0.1 dB compression point input power stands at 43.5 dBm, all achieved within a compact chip area of only 1 mm2.