In an exemplary embodiment, a phased array antenna comprises a bidirectional antenna polarizer and is configured for bidirectional operation. The bidirectional antenna polarizer may combine active implementations of power splitters, power combiners, and phase shifters. Furthermore, in another exemplary embodiment a bidirectional antenna polarizer has extensive system flexibility and field reconfigurability. In yet another exemplary embodiment, the bidirectional phased array antenna operates in “radar-like” applications where the transmit and receive functions operate in half-duplex fashion. Furthermore, in exemplary embodiments, the phased array antenna is configured to operate over multiple frequency bands and/or multiple polarizations.