Generation of Broadband High-Purity Dual-Mode OAM Beams Using A Four-Feed Patch Antenna: Theory and Implementation

Yuhan Huang; Xiuping Li; Qingwen Li; Zihang Qi; Hua Zhu; Zaid Akram; Xing Jiang

doi:10.1038/s41598-019-49377-6

Generation of Broadband High-Purity Dual-Mode OAM Beams Using A Four-Feed Patch Antenna: Theory and Implementation

Sci Rep. 2019 Sep 10;9(1):12977. doi: 10.1038/s41598-019-49377-6.

Authors

Yuhan Huang^{1

2

3}, Xiuping Li^{4

5

6}, Qingwen Li^{1

2

3}, Zihang Qi^{1

2

3}, Hua Zhu^{1

2

3}, Zaid Akram^{1

2

3}, Xing Jiang⁷

Affiliations

¹ School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing, 100876, China.
² Beijing Key Laboratory of Work Safety Intelligent Monitoring, Beijing University of Posts and Telecommunications, Beijing, 100876, China.
³ Key Laboratory of Universal Wireless Communications, Ministry of Education, Beijing University of Posts and Telecommunications, Beijing, 100876, China.
⁴ School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing, 100876, China. xpli@bupt.edu.cn.
⁵ Beijing Key Laboratory of Work Safety Intelligent Monitoring, Beijing University of Posts and Telecommunications, Beijing, 100876, China. xpli@bupt.edu.cn.
⁶ Key Laboratory of Universal Wireless Communications, Ministry of Education, Beijing University of Posts and Telecommunications, Beijing, 100876, China. xpli@bupt.edu.cn.
⁷ Guangxi College Key Laboratory of Microwave and Optical Wave Applications Technology, Guilin University of Electronic Technology, Guilin, 541004, China.

Abstract

A broadband four-feed circular patch antenna is demonstrated to generate high-purity dual-mode vortex beams carrying orbital angular momentum (OAM) for the first time. The electric field formula of the circularly polarized (CP) component is derived for analyzing radiation characteristics of different OAM modes, such as the CP property, phase and amplitude distributions. Theoretical calculation and numerical simulation results show that the four-feed patch antenna operating in the TM_n1 mode can generate ±n OAM waves. A prototype of a four-feed circular TM₂₁-mode patch antenna is fabricated and measured to verify the effectiveness of the theoretical analysis. The proposed antenna consists of a four-feed patch with an air-coupled parasitic patch and a four-way phase-shifting feeding network. Experimental results show that the proposed antenna can generate a left-hand CP OAM with mode l = +2 and a right-hand CP OAM with mode l = -2. The OAM beams are generated in a wide band from 5.50 to 6.50 GHz with a mode purity over 90%. The proposed method is very suitable for the generation of wideband, dual-mode and high-purity OAM beams in the microwave and millimeter wave bands.