Self-matching Self-compensating Air-filled Substrate Integrated Waveguide (AFSIW) Phase Shifter

This paper presents a multilayer phase shifter topology taking advantage of the air-filled substrate integrated waveguide (AFSIW) technology in the context of multilayer. By properly choosing the dimensions of this type of phase shifter, no additional transition is needed for matching purpose. Also, thanks to the AFSIW multilayer feature, a self-compensating effect is obtained, which allows realizing an equal-length configuration. For demonstrations, a phase shifter with a relative phase shift of 44.17 ± 5.64° is validated in measurement over the entire Ka-band. In this frequency range, an amplitude imbalance of −0.13 ± 0.44 dB is obtained. Nevertheless, the experiment validates the broadband responses with a return loss better than 11.33 dB. The proposed phase shifter structure allows realizing high-performance phase shifters without increasing the fabrication complexity.