Array Optimization for Maximum Beam Collection Efficiency to an Arbitrary Receiving Plane in the Near Field

In this article, an array optimization method for maximizing beam collection efficiency (BCE) to an arbitrary receiving plane in the near field is proposed. The proposed method considers each element pattern in an array; thus, optimization with mutual coupling is possible by using active element patterns. Besides, the proposed method can consider the polarization direction of a receiving antenna since the optimization problem is calculated in vector form. The problem of maximization of BCE boils down to the generalized eigenvalue problem, and the best solution can be obtained mathematically. The results obtained via numerical analysis in various calculation models indicate the validity of the proposed method. Optimization is then performed using the active element patterns obtained from electromagnetic simulation. Based on the comparison of the results without considering mutual coupling in the optimization, it is confirmed that the proposed method yields better results, such as lower reflection and antenna losses and higher BCE and transmission efficiency, by using active element patterns.