In-Line Rectangular Waveguide Filter Based on Combined Single/Dual-Mode Resonators

This paper proposes a filter based on a combination of dual-ridge dual-mode resonators (DRDMR) and single-ridge single-mode resonator (SRSMR). A DRDMR can be used as a transversal unit to create a transmission zero (TZ), while the SRSMR is connected to each DRDMR to achieve an in-line configuration of the filter. By adjusting the resonant frequency of the DRDMR, a symmetric response can be achieved. To validate the feasibility of the design, a fifth-order in-line filter with symmetrically distributed TZs is designed and fabricated. The measured result is consistent with the simulated result.