This article presents a method to increase the isolation and control the operating frequency of a circulator. The internal signal flow of a circulator is analyzed, and the through-port reflection to cancel out the leakage signal is investigated. A reflection coefficient controller (RCC) is designed to ensure that such reflection occurs at the operating frequency. In addition, the operating frequency can be tuned by using two varactor diodes of the RCC for an arbitrary value of the antenna impedance. The experimental results from the proposed method show isolation of 70 dB and an insertion loss of -1.4 dB at the operating frequency. Moreover, the operating frequency can be changed from 2.2 to 2.8 GHz with high isolation for an arbitrary antenna impedance.
|Number of pages||7|
|Journal||IEEE Transactions on Microwave Theory and Techniques|
|Publication status||Published - 2021 Aug|
Bibliographical noteFunding Information:
Manuscript received February 1, 2021; revised March 23, 2021; accepted April 19, 2021. Date of publication May 25, 2021; date of current version August 5, 2021. This work was supported in part by the CTO Future Technology Center, LG Electronics, and in part by the Institute of Information and Communications Technology Planning and Evaluation (IITP) Grant funded by the Korean Government (MSIT) under Grant 2020000218. (Corresponding author: Byung-Wook Min.) Donghyun Lee, Gisung Yang, and Byung-Wook Min are with the Department of Electrical and Electronic Engineering, Yonsei University, Seoul 120-749, South Korea (e-mail: firstname.lastname@example.org). Jong-Hyuk Park is with Hyundai Mobis, Yongin 449-910, South Korea.
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All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Electrical and Electronic Engineering