A Compact Ka-band Asymmetric SPDT Switch in 0.15-μm GaN-on-SiC Technology for 5G Applications

This paper presents a novel compact Ka-band asymmetric single-pole double-throw (SPDT) transmit/receive (TRx) switch for 5G applications in a 0.15-μm GaN-on-SiC process. The inductive susceptance of the OFF-STATE branch is harnessed to create resonators, which are subsequently incorporated with coupled-resonators to achieve wideband bandpass transmission characteristics for TRx. In the RX branch, the parasitic parameters of the additional series switch device are leveraged to alternate the coupling parameters of the resonators between TX and RX modes, aiming to enhance the RX insertion loss (IL) and TX isolation (ISO) performance. The chip size is 0.9 × 1.2 mm². Measurement results show that, from 24 to 33 GHz, the proposed switch features an IL of less than 1.0 dB in TX mode, and less than 2.71 dB in RX mode. The measured TX-to-RX ISO is better than 17 dB in TX mode.