Design of a Dual-Frequency Retrodirective Array

A dual-frequency retrodirective array is proposed. By using two separated antenna arrays and double balanced passive mixers, the proposed system can achieve dual-frequency retrodirectivity in a bidirectional way. The low-frequency interrogating signal can be retransmitted at the high frequency, and it can also work in a reverse order. The proposed array has the advantages of low cost and high isolation between interrogating and retransmitting signals. The bidirectional characteristic can make it very useful in the two-way communication system. A four-element prototype is designed and fabricated. Measured results show good retrodirective performance.