A 2 X 2-element sequentially rotated patch antenna array for a mobilesat briefcase antenna system

This article describes the design and development of a 2 X 2-element array for a briefcase antenna to be used with the Australian mobile satellite communications system Mobilesat. The array uses aperture-coupled circular microstrip patch antennas and a sequential feeding technique to obtain the required impedance and ellipticity bandwidth. To achieve the low-cost design, radiating elements are developed with the use of thin-film epoxy and foam, and the feeding network is etched on the R/T Duroid 5880 substrate. The measurements indicate approximately 13-dBi antenna gain and less than 1.6-dB axial ratio across the Mobilesat frequency band.