Sub-7 GHz Circularly Polarized Dielectric Resonator Antenna Array for Full-Duplex Applications

A novel high-isolation, monostatic, circularly po-larized (CP) simultaneous transmit and receive (STAR) array dielectric resonator antenna (DRA) is presented. The proposed in-band full-duplex (IBFD) CP DRA system consists of 32 identical elements for each transmit and receiver part. Each element includes two rectangular dielectric resonators with different permittivity of 5 and 10 excited by a vertical strip connected to the microstrip line at the backplane. A stub connected to the ground plane is added between Rx and Tx to improve the isolation. In addition, an inverted U-shaped parasitic strip is carefully placed between two feeding networks to further enhance the TX/RX isolation. The measured results exhibit high TX/RX isolation of more than 50 dB over the desired operating bandwidth from 4.8 GHz to 4.95 GHz with a high total efficiency greater than 85% and a peak gain of about 18.7 dBi for both Port 1 and Port 2.