Design and Fabrication of a Compact Low‐Cost U‐Band Waveguide Orthomode Transducer and Antenna Module

ABSTRACT In this study, we fabricated a U‐band orthomode transducer (OMT) designed to measure the total radiated power (TRP) of an emission source and evaluated its performance through experiments and simulations. The proposed OMT achieved low loss and high isolation through a coupling slot and septum‐based matching stub structure. To solve the problems of complicated fabrication and high cost that affect conventional multi‐segmented OMTs, the proposed design adopts a simpler structure that allows easy and low‐cost monolithic fabrication. In addition, we investigated the mechanical structure and manufacturability of the transducer using a cross‐simulation analysis between CST and HFSS. The fabricated OMT was combined with a choke‐ring antenna to detect electric fields in an OTA (over‐the‐air) test. The measured reflection loss, radiation pattern, and gain of the OMT and the antenna module indicated satisfactory performance in measuring TRP.