Substrate-Integrated-Waveguide (SIW) Single-Pole-Double-Throw (SPDT) Switch for X-Band Applications

A substrate-integrated-waveguide (SIW) single-pole double-throw (SPDT) switch is presented for X-band applications. Inductive posts with rectangular slots are embedded in the SIW to control the traveling EM wave. By adding PIN diodes on the top slots of the inductive posts, we achieved the ability to switch in the SIW technology; then, an SIW SPDT switch was designed. The proposed SPDT switch has a measured isolation (S31) of greater than 10 dB, isolation (S32) of greater than 15 dB, and an insertion loss (IL) of less than 2.55 dB, from 8.24-10.36 GHz.