Decoupled Transmit Beampattern Synthesis for Frequency Diverse Array Radar with Nonlinear Frequency Offsets

Frequency diverse array (FDA) radar has more degree of freedom in beamforming and modulation than conventional phased array radar. When the phase points to the fixed direction, the range of interest can also be specified by adjusting the frequencies of elements in linear array. This characteristic of frequency diversity makes an additional offset in the beampattern for both the range and angle dimension. The design of frequency and array element determine the performance of FDA radar. In this paper, the focused beam pattern is synthesized by using the proposed nonlinear frequency offsets in uniform linear frequency diverse array radar. Specifically, the improved μ-law function is used to calculate the inhomogeneous cell spacing and the sym-metric mapping is used to generate nonlinear frequency offset. The range-dependent and angle-dependent coupling is eliminated to achieve the dot shaped beampattern for the accuracy target estimation. Simulations and results show the effectiveness of the new strategy and verify its superiority to compare with other methods.