Full-duplex retrodirective array using mutually-exclusive uplink and downlink modulation schemes

This paper introduces a new architecture implementing full-duplex communication using a retrodirective array transceiver. The array scheme overcomes the difficulty of corruption of the outgoing retrodirected signal by the incoming interrogation signal inherent when using phase conjugation mixers. To remedy this problem, mutually-exclusive modulation techniques are utilized: uplink data is contained in time domain while the downlink data is contained in the polarization of the retrodirected signal. A phase conjugation mixer which is also able to modulate the polarization sense of the output radiation is also discussed for use in the retrodirective transceiver array.