FDA–MIMO radar transmitting subaperture design and anti-interference performance analysis

The hybrid of the frequency diversity array (FDA) radar and multiple-input multiple-output (MIMO) radar, namely, FDA–MIMO radar, provides more degrees of freedom and improves the overall performance of the system. The essence of FDA–MIMO radar transmitting subaperture design is to divide the transmit array into multiple subapertures to improve the interference suppression capability of the radar. Among them, orthogonal waveforms are transmitted between each subaperture, and each element inside the subaperture transmits the same waveform. Aiming at the problem of how the subaperture design of the FDA–MIMO radar affects its interference suppression performance, we analyzed the two aspects of the normalized beampattern and (non-)adaptive beamforming. We conclude that when interference is dominant, setting the number of subapertures to half of the number of transmit array elements can effectively reduce the sidelobe level and increase the output signal-to-interference-plus-noise ratio. A large number of simulation results verify the effectiveness and superiority of this method.