High OFF-State Suppression Filter-Integrated Switch Based on Split Ring Resonator

In this paper, a single-pole single-throw (SPST) filter-integrated switch applying a PCB process is designed. The switch based on a split ring resonator (SRR) with p-i-n diodes is able to achieve the switching function by controlling the states of the diodes and realizes high OFF-state suppression (OSS) performance as well as good selectivity and return loss (RL). The core size of the circuit is $0.17 \lambda_{g}{ }^{*} 0.51 \lambda_{g}$. Simulation results show that the center frequency of the switch is 1 GHz and the fractional bandwidth (FBW) is 9%. In the ON-state, the insertion loss (IL) is less than -1.7dB, the RL is higher than -20dB, with a maximum value of -53dB. In the OFF-state, the OSS is higher than -90dB in-band and -17.7dB out-of-band.