Development of microstrip reflectarray based monostatic STAR antenna

A co-polarized microstrip reflectarray antenna for monostatic simultaneous transmit and receive (STAR) applications is proposed. It is developed with a single broadside radiation and realized by double-layered variable-sized stacked square patches. Two feeding horns, one is for transmitting while the other one is for receiving, are placed mirrored on the reflectarray aperture by comprehensively considering the spillover loss, the blockage and the focal-diameter ratio as well as the isolation between the two horns. To verify the proposed antenna, a Ku-band demonstrator is developed and examined. Measurements show that the developed antenna achieves a high isolation of over 35 dB from 14 GHz to 16 GHz, the maximum isolation is up to 54 dB at 15.9 GHz, and the measured maximum gain is up to 25.1 dBi. The proposed reflectarray antenna based monostatic scheme features simple architecture, high gain, high isolation, and low sidelobe, which could be an attractive candidate for STAR applications.