Bandwidth Tunable and Compact Band-Pass Filter (BPF) Using Complementary Split Ring Resonators (CSRRS) on Substrate Integrated Waveguide (SIW)

Abstract

In this paper, we present a novel bandwidth tunable bandpass filter (BPF) loaded by complementary split ring resonators (CSRRs). On substrate integrated waveguide (SIW), the CSRRs are modeled and deployed to implement BPFs with tunable bandwidth capability. The microwave tunable circuits are designed in order to observe the various coupling coefficients and external quality factors by changing the orientations of the CSRRs. Four different configurations of filters are proposed and fabricated. These structures provide compact size as well as high frequency selectivity due to the use of the subwavelength resonators preserving sharp rejection and an evanescent wave propagation mode below the waveguide cutoff. Attractive performances of tunable BPFs are validated theoretically and experimentally.