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A Q‐band compact high‐performance double‐ridged orthomode transducer
Author(s) -
Zhong Weiye,
Yin Xiaoxing,
Shi Shengcai
Publication year - 2019
Publication title -
international journal of rf and microwave computer‐aided engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.335
H-Index - 39
eISSN - 1099-047X
pISSN - 1096-4290
DOI - 10.1002/mmce.21982
Subject(s) - transducer , optics , differential phase , return loss , phase shift module , feed horn , insertion loss , polarization (electrochemistry) , port (circuit theory) , materials science , physics , french horn , electrical engineering , phase (matter) , acoustics , engineering , dipole antenna , chemistry , quantum mechanics , antenna (radio) , periscope antenna
In this article, a Q‐band compact waveguide orthomode transducer (OMT) based on a stepped double‐ridged waveguide is presented. By using a symmetrical structure, good output return losses of above 20 dB are obtained from 35 to 50 GHz. In particular, the measured insertion losses are as low as 0.15 to 0.4 dB over the entire band for both polarization channels with an improved assembly configuration. The measured cross‐polarization levels are well below −37 dB, while the circular‐polarized output port isolation is less than −20 dB combined with a feed horn and a differential phase shifter. The developed OMTs have been used in a Q‐band two‐beam cryogenic receiver on the Tianma Radio Telescope, contributing only 1 to 2 K noise at an operating temperature around 20 K.