A Miniaturized Substrate Integrated Waveguide Bandpass Filter Using Stub-Loaded Technique

In this paper, a broadband substrate integrated waveguide filter structure loaded with stubs at the source and load ends is proposed. The miniaturization of the filter is realized by using a quarter-mode circular substrate integrated waveguide as the resonator. At the same time, the groove line is etched on the upper surface of the resonator and a new parallel stub structure is loaded at the input and output ends. Through simulation optimization and physical processing, the center frequency of the filter is 19.45GHz, the return loss is better than 16dB, and the 3dB bandwidth is 3.70GHz, which verifies the correctness of the design.