Ultra-wideband dual-linear polarized phased array with 60° scanning for simultaneous transmit and receive systems

We present a novel ultra-wideband (UWB) dual-linear polarized phased array designed for simultaneous transmit and receive (STAR) monostatic antenna systems. The dual-linear polarized array employs a tightly coupled dipole topology that achieves an UWB operation from 2GHz to 18GHz, viz 9∶1 bandwidth. Also, its port to port isolation is at least 45dB at broadside. The array consists of tightly coupled dipoles that are integrated with a folded Marchand balun. The latter serves as a balanced feed to a 50Ω source. One of the array polarizations is used for transmission and the other for reception. To improve scanning performance, the traditional dielectric superstrate is replaced with a frequency selective surface. Notably, the proposed tightly coupled dipole array (TCDA) scans down to 60° in both E and H planes with a port to port isolation of at least 35dB across the entire 9∶1 band.