X - band microstrip planar matched array for high gain & low sidelobes

Abstract

A three by four element broadside X-band microstrip planar array centered at 7.5 GHz was designed for high gain, low sidelobes and good impedance matching. The design starts with simulation of single patch in Matlab® followed by its optimization in Advanced Design System (ADS) Momentum for high gain. It was achieved by over sizing the patch dimensions and making it resonant at the same desired center frequency. A four element array of such patches was designed. Intra-element spacing and feed line dimensions were optimized for low sidelobes and impedance matching with transmitter. Then three such arrays were used to design a 3 × 4 element array. Inter-array spacing was optimized to achieve low sidelobes. The design was simulated and optimized in Momentum employing Method of Moments (MoM) to take into account the effect of mutual couplings of all the elements. The arrays were fabricated and tested in anechoic chamber. Microstrip power divider was used to feed the array by single source.