Design of a Wideband, High Steering Angle and Low Side-Lobes Levels Matrix Antenna

Abstract

This paper presents the use of pixel-type radiating elements in the context of broadband beam steering. The elements are composed of a resonant cavity topped by a frequency selective surface, fed via a patch antenna and filled with dielectric substrates. This pixel antenna has a wide -10 dB matching band from 1.22 to 1.61 GHz, which corresponds to a 27% fractional bandwidth. It has an angular aperture greater than 124° and a realized gain between 3.3 and 3.8 dBi over the whole matching band. An array composed of 5 elements has been simulated and allows a steering on a range of ±60° in the E plane while keeping the gain variation below 3 dB. A prototype has been manufactured and presents a steering capacity between -56 and 53° on the whole band with side-lobes levels lower than -8.1 dB whatever the angle.