Data Modulation of a Reflection-Type Retrodirective Array

A simple data modulation scheme capable of being directly integrated with a reflection-type retrodirective array (RDA) is experimentally validated. The conventional reflection-type RDA is reinvestigated in order to introduce data modulators into the array network without altering the circuit configuration, as well as retransmitted radiation pattern. Quadrature phase-shift keying modulators are developed and integrated with the RDA as a proof of concept. The measured error magnitude vector of the retransmitted signal, with a data rate of 4 Mb/s and an analysis bandwidth of 8 MHz, is 9.1% in an anechoic chamber. The retransmitted wave, in the meantime, remains pointing to the direction of arrival.