A DUAL-POLARIZED FABRY-PEROT CAVITY ANTENNA AT KA BAND WITH BROADBAND AND HIGH GAIN

A broadband Fabry-Perot cavity antenna (FPCA) operates at Ka band with high gain and dual-polarization is reported. The proposed antenna employed a double-sided complementary-circular partially reflective surface (PRS) to enhance the directivity bandwidth. A square patch coupled by two orthogonal slots and fed by two microstrip lines was applied as the primary feed to achieve dual- polarization operation. To further improve the impedance bandwidth and directivity, a series of metal vias were suggested to surround the primary patch. This FPCA design was verified by the measurements. The experimental results show that the common impedance bandwidth of the two ports for the reflection coefficient (S11 )b elow10 dB is 2.5 GHz from 34 GHz to 36.5 GHz (7.1%), which covers the common 3 dB gain bandwidth of the two ports. At the center frequency of 35 GHz, the measured peak gains at the two orthogonal ports are 16.1 dBi and 15.1 dBi, respectively. The isolation between the two ports is higher than 30 dB within the bandwidth.