Polarization Diversity Controllable Monopulse Antenna Array Design

The design of a compact and wideband circularly polarized (CP) Monopulse antenna is presented. Firstly, the small-sized element (13mm $\times13$ mm), with impedance bandwidth (BW) 80.5% (4.3-10.1 GHz) axial ratio (AR) 48.1% (6-9.8 GHz), gain 7.2 dBic designed. array structure consists two rat-race couplers; metalized via holes that generate sum difference patterns, four branch-line couplers for CP characteristic improvement. proposed capable controlling diversity in both beams. Additionally, 50% BW 25% 3-dB AR results also null-depth less than −48 dB, it convenient tracking purposes.