A Reconfigurable Filtering Circulator/Isolator With Continuously Controllable Center Frequency and Insertion Phase

作者：Yuhang Ning, Zhihua Wei, Bin Liu, Pei‐Ling Chi, Tao Yang · 发表于：IEEE Microwave and Wireless Technology Letters · 年份：2025 · DOI：10.1109/lmwt.2025.3557918 · 被引用次数：6 · 研究领域：Magnetic Field Sensors Techniques、Magneto-Optical Properties and Applications、Advanced Adaptive Filtering Techniques

A reconfigurable filtering circulator/isolator (RFCI) with tunable frequency and insertion phase based on the spatiotemporal modulation (STM) method is presented. The proposed RFCI mainly consists of three parallel resonatorLCtanks cascaded in a delta topology. With oneLCtank located at each port, both the receiver (Rx) and transmitter (Tx) channels exhibit a second-order filtering response. By adding STM signals in the delta topology, a filtering circulator is obtained. Meanwhile, two phase control networks (PCNs) are added at Rx and Tx ports, respectively. By adjusting the PCN, the insertion phase of the path from the antenna (Ant) to Rx and the one from Tx to Ant can be independently controlled while keeping all amplitude responses unchanged. Furthermore, either Rx or Tx can be turned off, thus transforming the proposed circuit into a filtering isolator with a controllable insertion phase based on signal cancellation. It integrates a bandpass filter (BPF), circulator, isolator, and phase shifter (PS) into a single, compact device. A prototype circuit is fabricated and measured for the proof-of-concept demonstration purposes.