A Highly Isolated Dual-Band Substrate Integrated Waveguide Phase Shifter With Large Phase Tuning Range

In this paper, a novel dual-band substrate integrated waveguide (SIW) reflective-type phase shifter is presented. It employs a dual-mode SIW hybrid coupler, which can concurrently couple the TE10 and TE20 modes of the SIW, forming two passbands in the meantime. By introducing and then tuning multiple-resonance loads at the output ports of the coupler, independently controllable phase shift with a large tuning range in the two passbands can be achieved. Moreover, by making use of the orthogonality of the TE10 and TE20 modes, the cross-interference between the two passbands can be suppressed to an extremely low level across the whole phase tuning process, achieving a much higher isolation level compared to the state-of-the-art dual-band phase shifters. As a demonstration, a dual-band phase shifter prototype with two operating frequencies at 2.4 GHz and 4.55 GHz is designed and measured.