Radiation patterns of a horizontal electric dipole in a four-layered region and applications for microstrip antennas

ABSTRACT

The present work focuses on the radiation field excited by a horizontal electric dipole (HED) in a four-layered region composed of a perfect conductor covered with two dielectrics and the air above. Analytical expressions for the radiation field are derived for the case of both the source and the observation point being on or near the air-dielectric boundary. The propagation characteristics of the interference phenomenon are investigated. The radiation field components undergo sharp interference as the relative permittivities and dielectric layer thicknesses increase. When the observation angle $\mathrm{\Theta }\ge {88}^{\circ }$, the trapped surface wave predominates in the total field. Otherwise, the total field is determined primarily by the lateral wave. Due to the useful applications for microstrip antennas, radiation patterns of a patch antenna with specific current distributions are investigated. Some special cases of interest are discussed. The proposed formulas offer the potential to develop planar four-layered circuit structures.

KEYWORDS:

• Radiation field
• trapped surface wave
• horizontal electric dipole
• four-layered region
• microstrip antenna

Acknowledgments

The authors are grateful to all referees for their constructive comments and suggestions in improving the quality of this paper. The authors thank AiMi Academic Services (www.aimieditor.com) for English language editing and review services.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study has been supported by the National Natural Science Foundation of China [grant numbers 61271086 and 60971057].

Notes on contributors

Zhu Hong Lin

Zhu Hong Lin was born in Wenzhou, Zhejiang, China on October 18, 1993. She received the BS degree in electronic science and technology from Southwest Jiaotong University, Chengdu, China, in 2016. She is currently working toward the PhD degree in electromagnetic field and microwave technology with the College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, China. Her current research interests include radio wave propagation theory and its applications.

Zhen Ting Chen

Zhen Ting Chen was born in Yiwu, Zhejiang, China, on July 7, 1995. He received his BS degree in Electronic and Information Engineering from Hefei University of Technology, Hefei, China, in 2017. He is currently working toward the MS degree in electromagnetic field and microwave technology with the College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, Zhejiang, China. His current research interests include radio wave propagation and antenna theory.

Kai Li

Kai Li was born in Xiao County, Anhui, China, on February 10, 1968. He received his BS degree in physics from Fuyang Normal University, Anhui, China, in 1990, MS degree in radio physics from Xidian University, Xian, Shaanxi, China, in 1994, and PhD degree in astrophysics from Shaanxi Astronomical Observatory, the Chinese Academy of Sciences, Shaanxi, China, in 1998, respectively. From August 1990 to December 2000, he was on the faculty of China Research Institute Radiowave Propagation (CRIRP). From January 2001 to December 2002, he was a postdoctoral fellow at Information and Communications University (ICU), Daejeon, Rep. of Korea. From January 2003 to January 2005, he was a research fellow with the School of Electrical and Electric Engineering, Nanyang Technological University (NTU), Singapore. Since January 2005, he has been a professor with the Department of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, China. His current research interests include classic electromagnetic theory and radio wave propagation. Dr. Li is a senior member of the Chinese Institute of Electronics (CIE) and a member of the Chinese Institute of Space Science (CISS).