Frequency diverse phase-conjugating retrodirective array with simultaneous range-focusing capability for multi-targets

In this paper, we propose a new concept of frequency diverse phase-conjugating retrodirective array (FD-PCA) with range-focusing capability for multi-targets. In the conventional PCA, the phase-conjugating mixers in each channel are fed from a common LO signal at twice the RF frequency. In the proposed FD-PCA, an additional small frequency offset across the phase-conjugating mixers is added. Due to the exploitation of both frequency diversity and retrodirective technique, the range and the angle in the phase term of the array factor are decoupled, and thus the range-focusing can be controlled independently through phase weighting. The theoretical analysis of FD-PCA on three types of frequency offsets are presented. They are linear incremental frequency offset, time-dependent frequency offset, and logarithmically increasing frequency offset. Simulated results show that the FD-PCAs are superior to FDAs for all the three types.