Joint Range and Angle Estimation Based on Sub- Array Scheme with Frequency Diverse Array Radar

Frequency Diverse Array (FDA) has its unique advantage in realizing Low Probability of Intercept (LPI) technology for its beam pattern is related to the range, time and angle. In this paper, a sub-array scheme of range-angle joint estimation of a target for Frequency Diverse Array (FDA) radar is proposed. To solve the problem of distance and angle response coupling of basic ULA FDA radar, the entire array is divided into two sub-arrays, which employs two different frequency offsets. For aperture extension, each sub-array adopts difference co-array structure to provide O(N) degrees of freedom by only N physical sensors when the second-order statistics of the received data is used. Therefore, the targets range and angle can be estimated directly with the subspace-based multiple signal classification algorithms. The estimation performance is examined by analyzing the Cramer-Rao Lower Bound (CRLB) versus Signal-to-Noise Ratio (SNR). Simulation results show that the proposed approach is effective to realize the joint range and angle estimation of FDA.