Design and analysis of an electrically steerable microstrip antenna for ground to air use

Abstract: A single-feed circularly polarized microstrip antenna array,operating at 2.45 GHz, have been analyzed and designed. Theantenna is mainly intended to be used for reception of a videosignal transmitted from an unmanned aircraft, but can be used forother applications as well. Due to the fact that it is supposed tobe used in a switched system, the beam width is quite narrow.Measurements of the antenna shows that it have a half power beamwidth of 40 degrees. For a VSWR lower than 1.5 and an axial ratiolower than 3 dB the band width is 80 MHz centered at 2.44 GHz.The side lobe levels are lower than -23 dB.The antenna is designed to be simple in layout due to the factthat it should be as robust as possible against manufacturingfaults.