Scanning characteristics of ferrite fed microstrip array antenna

Abstract

A new ferrite fed microstrip scanning array antenna is proposed which is capable of beam scanning in the azimuthal plane as well as in the elevation plane. The antenna consists of eight microstrip arrays, each having six elements in cascade. The antenna is fed with a ferrite loaded rectangular to circular waveguide transition. The coupling between the feed system and different arrays is achieved through slots cut in the circular waveguide. Theoretical investigations of the proposed antenna exhibit a beam scanning of ±180° in the azimuthal plane with the help of dc bias and 90c in the elevation plane for ±750 MHz deviation. A scan rate of 0.06° MHz-1 is achieved for each array antenna in the elevation plane, which makes it suitable for radar. Continuous uniform beam shift is observed during scanning.