Electronically Reconfigurable Varactor-Loaded HMSIW Bandpass Filter

Abstract

AbstractA varactor-loaded half-mode substrate integrated waveguide (HMSIW) reconfigurable bandpass filter (BPF) is proposed in this paper. The proposed BPF is composed of complementary split-ring resonators (CSRRs) and varactors. Meanwhile, a nonmetalized via is employed in the center of the CSRR. It is noted that the varactor is embedded into the nonmetalized via, which can significantly reduce the tunable filter size. By changing the reverse bias voltage of the varactor, the resonant frequency of the proposed filter can be adjusted. Moreover, low insert loss (IL) and wide tuning range can be achieved. In order to validate its practicability, a BPF with the frequency ranging from 1.9 GHz to 2.5 GHz is fabricated and good agreement between the simulated and measured results is observed.