A Dual-Passband Filter with Wide Stopband Based on Quarter-Mode Substrate Integrated Elliptical Waveguide

Abstract

In this paper, a miniaturized, dual-mode and dual-band (DMDB) filter with wide stopband based on quarter-mode substrate integrated elliptical waveguide (QMSIEW) is designed. QMSIEW is proposed by cutting along the substrate integrated elliptic waveguide (SIEW) magnetic wall. The filter realizes the first and the second passband respectively through the TMco10 and TMs210 modes of QMSIEW. The simulation results show that the frequency ratio of the designed DMDB filter is 2.49. The stopband bandwidth is extended to 2.3210 with a rejection level better than 20dB between the two passbands, and there are 5 transmission zeros (TZs) out of passbands.