关键词: 带通滤波器, 非谐振节点, 盒型拓扑结构, 基片集成波导, 广义切比雪夫滤波器, 非对称响应, 互补开环谐振器

Abstract: Bandpass filters (BPFs) with generalized Chebyshev response using dual-and single-mode substrate integrated waveguide (SIW) resonators are proposed according to the miniaturization and high performances.The box-like topology with an additional cross-coupled path realized by the fundamental mode (TE₁₀₁) of the dual-mode SIW cavity is proposed,and an additional transmission zero (TZ) is achieved.The traditional negative coupling structure is not required in the proposed structure,and two TZs can be realized;moreover,the structure has flexible responses that two TZs can be located on the lower and/or upper of passband.To improve the selectivity,a complementary split-ring resonator (CSRR) etched into the fourth-order SIW filter to design a filter with an extended box-like topology is studied,and the fifth-order filtering function with three finite TZs can be realized.To verify the feasibility,a symmetric and an asymmetric response fourth-order BPFs with center frequency of 10GHz and a fifth-order BPF with center frequency of 5.8GHz are designed.The corresponding coupling matrixes of box-like topologies with nonresonating node (NRN) are also given to verify the proposed structure.Finally,the designed SIW BPFs are processed and measured.The responses of coupling matrixes,simulated and measured results are in good agreement,which demonstrates the feasibility of designed filters with high performances using the proposed structures.

Key words: bandpass filter (BPF), nonresonating node (NRN), box-like topology, substrate integrated waveguide (SIW), generalized Chebyshev, asymmetric response, complementary split-ring resonator (CSRR)