Blake Chart Optimization of a VHF Phased Array Using Surrogate-Based Method

In this paper, an optimization methodology using surrogate-based method is proposed to optimize the Blake chart of a very high frequency (VHF) phased array. For transportable VHF radars with only a few antenna elements, the known beam-splitting effect can result in multiple nulls in the radiation pattern. This severely deteriorates the detection range curves in the Blake charts. A possible solution is to adjust the phase configuration of the phased array to search for the optimal Blake chart. Although the number of the phase configurations is huge, the surrogate-based optimization (SBO) adopted in this paper ensures the convergency, in contrast to the conventional simulated annealing (SA) and the typical genetic algorithm (GA). A uniform linear array (ULA) that consists of eight horizontally polarized dipole antennas is chosen for our simulation, and for such a case, the execution time of the simulation is within only 40 seconds using a common personal computer. The simulation results show that the detection range of the optimized Blake chart can be substantially increased.