Multi-antenna near field cancellation duplexing for concurrent transmit and receive

Concurrent transmit and receive with multiple antennas is demonstrated through near field cancellation. Full-duplex operation is possible through cancellation of the transmit signal at the receiver as much as 50dB. By exploiting symmetry in an array of antennas, a centrally located receiver is able to operate without saturation in the presence of high power transmit signals. The transmitters are able to provide spatial diversity and 360-degree azimuthal coverage while maintaining the requisite cancellation. We demonstrate the basic concept and then explore the criteria within the RF components needed to maintain suitable cancellation.