A Triple-Quasi-TEM-Resonance Dielectric Cavity for Bandpass Filter Design

This letter presents a triple-quasi-TEM-resonance dielectric cavity for compact bandpass filter design. The proposed dielectric cavity is silver coated and has three blind holes which form three distinct quasi-TEM mode resonators. The external coupling structure for the resonator is realized by tapping hole. The inter-resonator couplings are realized and controlled by slots on the outer surfaces of the dielectric block. A three-pole filter with two controllable transmission zeros is designed and implemented. The measured results agree well with the simulated results, verifying the proposed triple-resonance dielectric cavity structure and coupling mechanisms.