Design of Compact Dual Band Quarter Mode SIW Filter for Ku and Ka Band Applications

This paper presents a compact dual band Quarter Mode Substrate Integrated Waveguide (QMSIW) filter for Ku band and Ka Band applications. A triangular QMSIW cavity is coupled using Coplanar Waveguide (CPW) to achieve an isolation between the two pass bands. The two pass bands achieved are, one formed by the fundamental TE101 mode and the other formed due to higher order mode by TE102 mode. The QMSIW miniaturized structure is further miniaturized by loading the structure with the Complementary Split Ring Resonators (CSRR). The structure is designed and simulated over the RT/Duroid 6002 substrate having a thickness of 0.508 mm. The Insertion achieved in simulation is well below the required -15 dB for both the passbands. The resonant bands for Ku frequency band were obtained between 14.69 GHz and 15.52 GHz and for resonant band for Ka frequency band were achieved between 28.4 GHz and 29.52 GHz. Tunability of 100 MHz in lower passband and 200 MHz in upper passband is achieved using RF MEMS SPDT switch. The tunable filter is designed, analyzed and simulated using ANSYS HFSS