FULL-DUPLEX DUAL-FREQUENCY SELF-STEERING ARRAY USING PHASE DETECTION & PHASE SHIFTING

摘要

A self-steering retrodirective array capable of both full-duplex communication and maintaining a constant retrodirected power level uses an angle-detecting array (A) with a phase detector (20) to detect the angle of the incoming signal from a source and generate an error voltage signal (V_err), and a transmitting array (C) having a phase shifter controlled by the error voltage signal (V_err) to retrodirect a beam back in the direction of the source. A phase shifter in the receiving array (B) also ensures coherent combination of the incoming signal. The angle-detection array and transmitter array are RF-decoupled for full-duplex communication. The efficiency of the system is increased by using an interrogator signal at a much lower frequency than the transmitted signal. In a preferred embodiment, a simple two-element angle detecting array detects the direction of the source. Since the source angle is determined by measuring the phase difference between the two antenna elements, the angle detecting array is insensitive to the type of modulation used for the incoming signal.