High-gain and low-profile microstrip antenna using slot-loaded TM50 mode

Abstract

This paper presents a high-gain and low-profile microstrip antenna with single-layered substrate. The proposed antenna consists of a rectangular patch, which operates in higher order TM50 mode, and two identical slots etched on the patch. A four-element equivalent magnetic current array is constructed within a single cavity, including two from the radiating aperture of the patch and another two from the etched slots. Only one substrate layer and single feed are used here with the merits of low profile and simple feeding. High gain, e.g., 3 dB higher than conventional microstrip antenna operating in the fundamental mode, is obtained from the single-layered structure. The measured gain of 11.3 dBi is achieved with the antenna profile of 0.027λ 0 (λ 0 is the free-space wavelength of operating frequency), agreeing well with the simulations. The proposed antenna has the advantages of high gain, low profile, single feeding and low cost, with great potential in designing dual-polarized microstrip antennas and arrays with larger scale.