A direct RF-undersampling retrodirective array system

A retrodirective antenna system is a smart antenna system where signals received from a source are automatically sent back in the direction of the source. Undersampling (also named bandpass sampling) is a signal processing technique with which an RF signal is directly sampled at a rate related to its bandwidth rather than its highest frequency. In this paper, we incorporate the undersampling technique into a retrodirective antenna system, resulting in a new and simplified smart RF transceiving architecture: no analog RF mixers and local oscillators for frequency down-conversion are required. This has lead to a significant reduction in the number of the RF components required and therefore in the cost of the retrodirective system. Both simulation and experiments are presented and they show the effectiveness of the proposed design.