Frequency diverse array (FDA) has characteristics different from phased arrays due to the frequency offset introduced. To explore the performance of FDA, we analyze the generalized ambiguity function of coherent FDA based on multi-channel mixers and matched filters. We build an accurate and complete coherent FDA ambiguity function. Then, the peak shift of the ambiguity function is proposed because of the irregular weighting term in the model. We define sensitive array element to evaluate the influence of the irregular weighting on the FDA ambiguity function. Finally, the ambiguity function shaping method is proposed based on waveform and weight vector cascade optimization. Numerical results show that the complete and principal ambiguity functions have differences; the better the Doppler tolerance and longer waveform, the less effect of irregular weighting. Meanwhile, the proposed cascade optimization method can effectively generate a coherent FDA ambiguity function with good local performance.

This article investigates the strategy design problem between a multiple statistical MIMO radar network and a jammer, whose primary objective is to minimize their transmission power while satisfying a certain standard. Their conflict relationship is depicted as a two-person zero-sum(TPZS) game due to their adversarial nature. Mutual information (MI) is employed as the utility function where the multiple statistical MIMO radar network and the jammer can change their power allocation strategy to satisfy MI standards for the two players separately. The Stackelberg game is used to study and generate the equilibrium solutions for the strategy design between the multiple statistical MIMO radar network and the jammer. Finally, the simulation results show that, compared with other algorithms, the proposed method can save the leader’s total power under a certain MI standard, and has less algorithm complexity.

To simultaneously enhance the low interception and target detection performance, we proposed a robust method with low interception and detection shared waveform design based on the frequency diverse array multiple input multiple output (FDA-MIMO). We introduced an encoding-decoding-encoding to process the received signal. Considering the constant modulus constraint and the potential inaccuracies in angle estimation, we formulated an optimization problem involving the phase code waveform. The objective function was to minimize the transmitted gain while maximizing the received gain, thereby reducing the interception factor and enhancing the signal-to-noise ratio (SNR). To solve this fractional optimization problem, we introduced the auxiliary variables to transform the fractional problem into a difference problem. Taylor expansion and sequential convex programming (SCP) are utilized to convert the nonconvex problem into a series of convex sub-problems. Numerical results demonstrate the superiority of the proposed shared waveform.

The transmitted beam of frequency diversity array (FDA) has the range–angle–time coupling property, which has essential applicative potential in angle deception and active anti-jamming. In this paper, the concept of time index within pulse is introduced. Firstly, the phase characteristics of FDA-transmitted signals based on the time index within pulse concept are studied. Then, the deceptive angle performance of FDA-transmitted signals is discussed. The theoretical analysis and simulation results show that the phase characteristics of the FDA signal are not related to the range, but to the time index within pulse. With the phase center as the reference point, the phase is equal as long as the time index within the pulse is the same. Angle deception and active anti-jamming can be achieved using the optimized frequency increment of each FDA.

Due to suppression jamming by jammers, the signal-to-interference-plus-noise ratio (SINR) during tracking tasks is significantly reduced, thereby decreasing the target detection probability of radar systems. This may result in the interruption of the target track. To address this issue, we propose a multi-static radar power allocation algorithm that enhances the detection and tracking performance of multiple radars in relation to their targets by optimizing power resource allocation. Initially, the echo signal model and measurement model of multi-static radar are formulated, followed by the derivation of the Bayesian Cramér–Rao lower bound (BCRLB). The multi-objective optimization method is utilized to establish the objective function for joint tracking and detection, with dynamic adjustment of the weight coefficient to balance the tracking and detection performance of multiple radars. This ensures the reliability and anti-jamming capability of the multi-static radar system. Simulation results indicate that the proposed algorithm can prevent the interruption of jammer tracking and maintain robust tracking performance.

To address the contradiction between a small number of grid lobes and a narrow main lobe in the range dimension beampattern of conventional FDA-MIMO radar, a Cantor Multi-stage frequency offset FDA-MIMO(CMSEO FDA-MIMO) structure is introduced. Moreover, a combination of frequency offset and array element number configuration methods is proposed. We derived the relationship between the main lobe width and periodic range with frequency offset and fractal order. Furthermore, the frequency offset and array element order relation closed-form solutions for main lobe invariance and grid lobe reduction are derived. Simulation experiments demonstrate the effectiveness of the proposed method.