High Selectivity Waveguide Filtering Antennas Using Mixed-Mode Cavity Resonator

作者：Xiang, Kai-Ran; Chen, Fu-Chang^*; Chu, Qing-Xin; Xue, Quan

来源：IEEE Transactions on Microwave Theory and Techniques, 2022, 70(9): 4297-4307.

DOI：10.1109/TMTT.2022.3189355

• Antenna array
• cavity resonator
• filtering antenna
• high selectivity
• slot antenna
• synthesis

In this article, high selectivity filtering antennas are designed based on a mixed-mode cavity resonator, which is formed by adding a short-circuited metal cylinder at the center of a rectangular cavity. The resonant and coupling characteristics of the proposed resonator are analyzed in detail. The operating modes of the mixed-mode cavity are TE102 mode, TE012 mode, and quasi-TEM mode, which can be utilized to design filtering antennas with different transmission zero distributions. To demonstrate the concept, three slot antennas with 3rd-order filtering performance are designed and simulated, where two transmission zeros are introduced to improve the selectivity. Furthermore, a 5th-order filtering antenna array based on the mixed-mode resonator is designed and fabricated. The measured results are consistent with the simulated results, showing that a gain of greater than 13 dBi is achieved.