Multicarrier Directional Modulation Symbol Synthesis Using Time-Modulated Phased Arrays

In this letter, we present a new approach of using time-modulated phased arrays to synthesize multicarrier directional modulation (DM) symbols for physical-layer security. In particular, the modulated waveform synthesis is achieved with the careful design of the switching time sequences, instead of in digital baseband; thus, reducing the peak-to-average power ratio of signals going through the radio frequency (RF) chain, and only a single RF chain is required here. The operation principle and synthesis approach are elaborated and demonstrated. In addition, the efficacy of the proposed DM approach is validated via the bit-error-rate (BER) metric.