Range-dependent Beamforming with Frequency Diversity Uniform Circular Array MIMO Radar

The combination of conventional uniform circular array ( UCA) and multiple-input and multiple-output ( MIMO) radar leads to a flexible technique which enjoys the advantages of MIMO radar without sacrificing the main advantage of UCA radar. However, the UCA MIMO radar is limited to range-independent directivity; this limits the radar performance to mitigate non-desirable range-dependent interferences. In this paper, a new UCA MIMO radar with frequency diversity for range-dependent beamforming is proposed. The essence of the proposed method is each element of the UCA transmits a distinct waveform with a small frequency increment, the summation of signals in far-field has relationship with distance. Thus the beamforming is range-dependent. The effectiveness of the proposed technique is verified by numerical simulation results.