Fast Pencil Beam Pattern Synthesis of Large Unequally Spaced Antenna Arrays

Reducing the computational cost of large array pattern synthesis is attractive in many applications. In this paper, a fast pencil beam pattern synthesis method for large nonuniform antenna arrays is proposed. This method is based on an interpolation in a least square sense and iterative fast Fourier transform (FFT), i.e., interpolate the nonuniform distributed elements into uniform virtual elements, and then apply FFT to synthesis the uniform array. Thanks to the efficiency of FFT, the proposed method is much faster and can handle much larger arrays than the existing methods. To guarantee the interpolation accuracy, the choice of the interpolation parameters is discussed. Both linear and planar nonuniform array examples are shown to validate the advantages of the proposed method.