Compact broadband bi‐directional circularly polarized fan‐shaped patch with parasitic annular groove for S ‐band satellite applications

Abstract

A novel bi-directional circularly polarized (CP) antenna with low profile, real planar configuration and broad axial ratio (AR) bandwidth is presented for S-band satellite relay communication application. The designed antenna consists of four fan-shaped patches, a sequentially rotating feed network and ground plane with annular gaps. Four fan-shaped patches are directly integrated with the feed network on the same FR4 substrate for good impedance matching and compact size. To realize the two-way radiation characteristics and excellent AR bandwidth, one parasitic annular groove on the ground plane is designed. The sequential rotation feeding network can provide good port characteristics within the available bandwidth and good AR. The properties of designed antenna was tested to validate its simulation. The final prototype is 83 × 83 × 0.8 mm3 in size and it can generate a broad impedance bandwidth for voltage standing wave ratio (VSWR) <2 of 36.6% (2.32–3.36 GHz), 3-dB AR bandwidth of 21.3% (2.6–3.22 GHz) and gain over 5.4 dB in the bi-directional direction. The miniaturization, low-cost and good CP radiation for this proposed antenna make it a better candidate for future applications in the field of spacecraft relay communication.