2017 Volume 6 Issue 10 Pages 607-614
An active phased array antenna is capable of controlling not only the phase of each element but also the amplitude, and can therefore form a highly accurate beam. When an amplitude distribution range is wide, there occurs the problem of the power efficiency of an amplifier connected to each element decreasing. To operate the amplifier with high efficiency, it is necessary to limit an amplitude control range. This paper proposes a new pattern synthesis algorithm adapted to optimize the excitation amplitudes and phases of an APAA within a predetermined amplitude control range. The proposed method enables designing within the predetermined amplitude control range by introducing a mapping function representing the amplitude of a driven element, although the values of independent variables to be optimized using a conjugate gradient method are not limited. In addition, the proposed method does not require iterative calculation, and makes it possible to obtain the optimum excitation amplitudes and phases by only performing optimization design once. The proposed algorithm will be described while taking null formation by a linear array antenna as an example, and effectiveness will be examined by simulation.
