Wide-Stopband Substrate Integrated Waveguide Filter Power Divider Based on Through Glass Quartz Via (TQV) Technology

Abstract

This article presents a substrate integrated waveguide (SIW) filter power divider (FPD) based on glass substrate with a wide stopband. Couplings of TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">101</sub> and TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">103</sub> modes construct the passband of the FPD, which are transmitted by a T-type structure with resonators of different sizes to reduce parasitic patterns. The input and output ports are realized by electrical feeders, which penetrate into the center of resonant cavity. Combined with the lateral coupling structure, the parasitic passband caused by the even-high-order modes can be eliminated effectively. Utilizing the multimode transmission characteristics of waveguide resonators, electromagnetic waves of two modes are set to transmit in resonators of different sizes, effectively suppressing the resonance of higher order modes. In order to achieve a good isolation, an isolation resistor is introduced between two output ports to ensure the high efficiency of signal transmission. Consequently, an FPD with a center frequency of 35.5 GHz, a bandwidth of 1 GHz, and out-of-band suppression greater than six times the center frequency is designed, fabricated, and measured. Both theory and experiment have proved the effectiveness of the above method, and the simulation results are in good agreement with the measured results.