Passive Interference Cancellation in a 2×2 STAR MIMO Antenna Network

摘要

Passive cancellation of self-interference and cross-interference is examined under simultaneous transmit and receive (STAR) operation in a 2×2 multiple-input multiple-output (MIMO) node. Circularly-polarized antennas are connected to balanced feed networks for cancellation of the cross-interference created by the antenna-to-antenna coupling between the pair of transceiver antennas. A feedforward path connected between two transceivers in the MIMO node further improves the cancellation of the cross-interference. Measurement results from a two-antenna system with balanced feed networks show a total self-interference cancellation of over 40 dB and cross-interference cancellation of over 46 dB.