Abstract: This paper describes the performance of the Aperture Coupled Microstrip Planar Array in C-band. The basic concept of aperture coupling is to achieve the wide frequency bandwidth & low back radiation. The enhancement of the bandwidth in the present case is achieved by coupling to the microstrip antenna on one substrate from the microstrip line feed on another parallel substrate through an aperture in the ground plane, which separates the two substrates. A design procedure for aperture coupled microstrip antennas based on transmission line model is presented. The novel coaxial to microstrip line transition is devised and implemented to feed the aperture coupled microstrip antenna elements in planar array to achieve the wide impedance and pattern bandwidth. The experimental results of Return loss plot & Radiation pattern for aperture coupled microstrip planar array antenna are presented.

Keywords: C-band, bandwidth, Back radiation, Microstrip antenna, Co-axial to microstripline transition, planar array, Aperture coupling, Return loss, Radiation pattern.