Key Laboratory of RF Circuits and System, Ministry of Education, Institute of Antennas and Microwave Technology, Hangzhou Dianzi University, Hangzhou, China
Key Laboratory of RF Circuits and System, Ministry of Education, Institute of Antennas and Microwave Technology, Hangzhou Dianzi University, Hangzhou, China
Smart City Research Center of Zhejiang Province, Hangzhou Dianzi University, Hangzhou, China
Weiliang Yu
Key Laboratory of RF Circuits and System, Ministry of Education, Institute of Antennas and Microwave Technology, Hangzhou Dianzi University, Hangzhou, China
Huayan Jin
Key Laboratory of RF Circuits and System, Ministry of Education, Institute of Antennas and Microwave Technology, Hangzhou Dianzi University, Hangzhou, China
Zhen Liao
Key Laboratory of RF Circuits and System, Ministry of Education, Institute of Antennas and Microwave Technology, Hangzhou Dianzi University, Hangzhou, China
Zhongxiang Shen
School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore
This paper presents a 3D band-absorptive frequency selective rasorber (FSR). Such an FSR is absorptive within a specific band and almost transparent below the absorption band. The definition and evaluation of the band-absorptive FSR is initially provided and followed by the design concept of 3D FSR. An example is then proposed, whose unit cell is composed of 3D absorber and 3D band-stop FSS. An equivalent circuit model is established for understanding its operating principle. A prototype of the proposed 3D band-absorptive FSR is fabricated. The measured results show that it has an absorption band ( $\vert S_{11}\vert \le -10$ dB and $\vert S_{21}\vert \le -10$ dB) from 4.21 to 6.51 GHz, with a thickness of 0.17 wavelength at 4.21 GHz. Moreover, $\vert S_{21}\vert $ is higher than −1 dB at the frequencies below 1.28 GHz. The proposed band-absorptive FSR can be used as radomes for low-frequency antennas in military communications or spectrum monitoring systems.
