Varactor-tuned substrate integrated waveguide phase shifter

Summary form only given, as follows. In this paper, we present two design platforms of substrate integrated waveguide (SIW) phase shifter at 26 GHz. An inline phase shifter tuned by single varactor has a phase shift larger than 25 degrees over a 30% bandwidth. The variation of phase shift is less than 2.2 degrees within the band. The 180-degree reflection-type phase shifter has a measured phase shift of more than 180 degrees over a bandwidth of 13% and the variation of insertion loss is −3.8 ± 0.87 dB within a bandwidth of 15.3%.