A Compact and Broadband Elliptical Antenna With Metallic Walls for Low Cross-Polarization

Abstract

A multilayer compact and broadband elliptical microstrip antenna (MSA) is designed with low cross-polarization using shorting posts and metallic walls. Two dumbbell-shaped patches are stacked on top of a metallic elliptical fed patch. These patches are printed on an air-suspended FR-4 substrate in the area utilized by the elliptical patch. The dumbbell-shaped patches are directly coupled with the elliptical patch by embedding shorting pins between them at symmetrical positions which improve the bandwidth (BW) and cross polarization (X-pol). The antenna geometry is further enclosed in metallic walls to improve gain and to reduce X-pol and front-to-back ratio (FBR). A systematic study of the antenna design is presented. The designed multilayer elliptical MSA is a low-cost antenna with size 0.85λ × 0.58λ × 0.15λ and provides 43.8% BW (1.619–2.526 GHz) with peak gain of 9 dBi and FBR of more than 16 dB over BW. The antenna X-pol is below −20 dB from 1.7 to 2.52 GHz. The designed antenna can be used for IoT-based smart devices and 5G cellular services in sub-6 GHz frequency band. © 2025 Wiley Periodicals LLC.