A Laminated Wideband Dual Circularly Polarized Patch Antenna for X-Band Applications

A wideband differentially feed dual circularly polarized (CP) antenna is presented. It has a laminated structure with eight layers. The various layers in this antenna have different functions, which consists of parasitic radiating patches, Ш-shape electromagnetic aperture coupling and wideband miniaturized hybrid coupler (WMHC). The WMHC is a novel design that guarantees signal transmission across the entire X-band and effectively reduces size. Circular polarization is obtained due to orthogonal feed lines. As these concepts, a prototype antenna operated at X-band is simulated, fabricated, and measured. Measurements show that the prototype has a fractional bandwidth (VSWR < 2) of 26%, ranging from 8.5 GHz to 10.95 GHz. It has a maximum gain of 6.5 dBic and minor of 5.5 dBic. All feed ports isolation less than -16 dB. Moreover, the laminated structure makes it a good candidate for active phased array design.