IEEE Transactions on Applied Superconductivity
Quasi-Lumped Coplanar Waveguide Diplexers for a Multichroic Polarimeter
Sirui Ren, Tian Xia, Shiling Yu, Yu Wang, Mingzhu Zhang, Yuxin Qiu, Xiaohui Yan, Ruirui Fan, Xucheng Dai, Zhanzhang Mai, Zhongyu Shi, Yue Hong, Liming Zou, Haitao Wang, Hongli Zhu, Jiawei Liu, Haoyu Wang, Weijie Guo, Yiwen Wang, Yanru Song, Xiaohang Zhang, Ran Duan
Abstract
This article presents a multichroic Kinetic Inductance Bolometer (KIB) polarimeter that utilizes coplanar waveguide (CPW) diplexers. The CPW diplexers function as filters, providing two passbands centered at 220 GHz and 280 GHz. The high-quality-factor resonant units deliver excellent transmission and isolation characteristics. Additionally, the quasi-lumped-element resonator design enables a significant reduction in size compared to conventional microstrip diplexers. The entire polarimeter—comprising orthomode transducer (OMT) probes, diplexers, KIBs, and CPW feed lines—is integrated on a single plane, allowing for one-layer superconducting thin-film fabrication with a simplified process. The compact size, superior frequency response, and streamlined fabrication process make the proposed pixel scheme suitable for integrated array development.