Wideband isolator based on one-way surface magnetoplasmons with ultra-high isolation

Tao Jiang; Dan Liang; Huajie Liang; Lin Zou; Tianchi Zhou; Shiqing Li; Linfang Shen

doi:10.1038/s41598-024-68602-5

Wideband isolator based on one-way surface magnetoplasmons with ultra-high isolation

Sci Rep. 2024 Jul 29;14(1):17474. doi: 10.1038/s41598-024-68602-5.

Authors

Tao Jiang¹, Dan Liang², Huajie Liang², Lin Zou², Tianchi Zhou³, Shiqing Li⁴, Linfang Shen⁴

Affiliations

¹ Huzhou Key Laboratory of Terahertz Integrated Circuits and Systems, Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou, 313001, China. jiangtao@csj.uestc.edu.cn.
² Huzhou Key Laboratory of Terahertz Integrated Circuits and Systems, Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou, 313001, China.
³ School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China. zhou_tian_chi@163.com.
⁴ Department of Applied Physics, Zhejiang University of Technology, Hangzhou, 310023, China.

Abstract

In this paper, we present a new type of isolator based on one-way surface magnetoplasmons (SMPs) at microwave frequencies, and it is the first time that an experimental prototype of isolator with wideband and ultra-high isolation is realized using SMP waveguide. The proposed model with gyromagnetic and dielectric layers is systematically analyzed to obtain the dispersion properties of all the possible modes, and a one-way SMP mode is found to have the unidirectional transmission property. In simulation and experiment with metallic waveguide loaded with yttrium-iron-garnet (YIG) ferrite, the scattering parameters and the field distributions agree well with the analysis and verify the one-way transmission property. The isolation is found to be as high as 80 dB and the typical value of insertion loss is 1 dB. Besides, the one-way transmission band can be controlled by changing the magnetic bias. From theoretical analysis and simulation, it is found that with a tiny value of 10 Oe of the magnetic bias, the relative bandwidth can be tuned to be greater than 50%. Compared with conventional isolators, this one-way SMP isolator has the advantages of ultra-high isolation, wide relative frequency band, and requires much smaller bias field, which has promising potential in non-reciprocal applications.

Keywords: Gyromagnetism; Isolator; Nonreciprocity; Surface magnetoplasmons (SMPs); Yttrium–iron–garnet (YIG) ferrite.