  The combination of frequency diverse array (FDA) radar technology with the
multiple input multiple output (MIMO) radar architecture and waveform diversity
techniques potentially promises a high integration gain with respect to
conventional phased array (PA) radars. In this paper, we propose an approach to
the design of the transmitter and the receiver of a coherent FDA (C-FDA) radar,
that enables it to perform the demodulation with spectral overlapping, due to
the small frequency offset. To this purpose, we derive the generalized
space-time-range signal model and we prove that the proposed C-FDA radar has a
higher coherent array gain than a PA radar, and at the same time, it
effectively resolves the secondary range-ambiguous (SRA) problem of FDA-MIMO
radar, allowing for mainlobe interference suppression and range-ambiguous
clutter suppression. Numerical analysis results prove the effectiveness of the
proposed C-FDA radar in terms on anti-interference and anti-clutter
capabilities over conventional radars.
