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This article deals with the low-sidelobe shaped-beam pattern synthesis (SBPS) problem using two nonuniformly spaced subarray configurations, including amplitude and amplitude–phase subarray configurations. An optimization model is proposed for the SBPS problem to minimize the peak sidelobe level by jointly optimizing the subarray configuration and element excitations/positions. A typical advantage of the proposed model is to reduce the system control points while maintaining the benign array performance. However, the formulated problem is a mixed-integer nonconvex one, which makes it challenging. Besides, this problem cannot be directly solved due to the existence of coupling optimization variables. Thus, a set of auxiliary variables is introduced to move the coupling optimization variables into equality constraints. These equality constraints are converted into quadratic penalty forms and are added to the objective function. Then, an efficient iterative algorithm is proposed using the penalty-based optimization method, which solves the original problem by iteratively solving a series of subproblems based on the inexact block coordinate descent technique. Numerical examples with different beam patterns are performed to verify the effectiveness of the proposed algorithm. [ABSTRACT FROM AUTHOR]

In this paper, the problem of enhancing the detection performance of detector for target in partially homogeneous background is addressed. Based on a general measurement model, a new constant false alarm rate (CFAR) adaptive matched detector (AMD) is proposed through a two-step design procedure. The detection performance of the AMD is theoretically analyzed. Then, the correctness of the analytical results and the effectiveness of the AMD are validated through numerical experiments and IPIX radar data. To further improve the detection performance of AMD, optimal polarimetric waveform design is approached. The waveform is designed by optimally selecting the transmitted polarization that maximizes a non-central parameter of the detection probability. Numerical experiments are provided to validate the performance improvement by comparing the optimal AMD with the optimal adaptive subspace detector (ASD) and the fixed AMDs. Comparison results show that a gain of 1–5 dB is obtained by the optimal AMD. [ABSTRACT FROM AUTHOR]

• The proposed ADMM-based algorithm can accelerate the solving of beam pattern synthesis problem. • The proposed element pattern selection scheme is able to greatly shrink the possible pattern combination search space. • The proposed pattern selection and optimization algorithm can further suppress the peak sidelobe level about 0 dB to 4 dB. The paper considers the array beam pattern synthesis (BPS) problem with reconfigurable pattern elements (RPE). Both the array weight and the array pattern are optimized, which further suppresses the peak sidelobe level (PSLL) compared with the fixed pattern array. For the array pattern optimization, the conventional selecting of appropriate N elements from K radiation patterns requires to evaluate all possible K N choices, resulting in the non-deterministic polynomial-hard RPE selection problem. In this work, this problem is solved through investigating different element pattern combinations with randomly arranged pattern locations. In such way, the possible solutions to the RPE selection problem has an overall choices of C N + K − 1 K − 1 = (N + K − 1) ! N ! (K − 1) ! , which extremely shrinks the solution space. An algorithm with the RPE selection and array weight optimization is proposed for the BPS problem. Furthermore, the alterative direction method of multipliers (ADMM) framework is introduced to accelerate the computation speed. The proposed algorithm provides an effective scheme for generating appropriate RPE combinations for PSLL suppression, resulting in a wider-angular scanning ability for array antenna. Simulation results demonstrate 0 dB to 4 dB lower PSLL can be obtained compared with the algorithms based on the fixed element pattern. [ABSTRACT FROM AUTHOR]