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. The
antenna is mainly intended to be used for reception of a video
signal transmitted from an unmanned aircraft, but can be used for
other applications as well. Due to the fact that it is supposed to
be used in a switched system, the beam width is quite narrow.
Measurements of the antenna shows that it have a half power beam
width of 40 degrees. For a VSWR lower than 1.5 and an axial ratio
lower 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 fact
that it should be as robust as possible against manufacturing
faults.