ABSTRACT This paper presents the design and implementation of a novel high‐isolation absorptive traveling‐wave single‐pole double‐throw (SPDT) switch based on a 0.15 μm GaAs pHEMT process. The switch uses a multistage quarter‐wavelength microstrip structure to form a distributed signal path. It incorporates matched absorbing resistors and coupling capacitors at the isolation branches. This topology significantly improves return loss and isolation performance over conventional distributed switches, covering a wide frequency range. The structure reduces insertion loss in the ON state and enhances energy absorption in the OFF state. As a result, undesired reflections are suppressed. Measured results show the proposed switch achieves input/output return losses better than 9.5 dB, isolation port return loss better than 14.8 dB, insertion loss below 2.45 dB, and isolation > 25.2 dB over the 27–40 GHz frequency range. The design maintains a compact chip area of 1.1 × 1.1 mm 2 and demonstrates excellent performance in bandwidth, loss, and integration.
Jiang et al. (Wed,) studied this question.