AUTHOR=Yan Zhuoying , Zhong Weiye , Ma Jia , Zhang Hui , Zhang Chao , Pu Zhengwei , Wang Junzhi 

TITLE=Design of an eight-hole directional coupler for W-band cryogenic receivers

JOURNAL=Frontiers in Astronomy and Space Sciences

VOLUME=Volume 12 - 2025

YEAR=2025

URL=https://www.frontiersin.org/journals/astronomy-and-space-sciences/articles/10.3389/fspas.2025.1538558

DOI=10.3389/fspas.2025.1538558

ISSN=2296-987X

ABSTRACT=For the system noise temperature calibration of the K/Q/W triple-band cryogenic receiver on Tianma Radio Telescope (TMRT), a design of W-band eight-hole waveguide directional coupler is proposed in this paper. Based on the hole coupling principle proposed by Gian Guido Gentili, a simulation model of the eight-hole coupler is designed by ANSYS HFSS. Both simulation and experimental results demonstrate that the coupler exhibits excellent performance across the 80–110 GHz, with a coupling coefficient ranging from −25 dB to −26 dB, a directivity greater than 11 dB, and an isolation below −38 dB.