Fast Full-Wave Synthesis of Printed Antenna Arrays Including Mutual Coupling

Abstract

A fast full-wave scheme is presented for the analysis of large printed antenna arrays, making use of the macrobasis functions (MBFs) technique. The interaction between MBFs is computed efficiently through a combination of the contour-fast Fourier transform (C-FFT) and interpolatory MBF-based techniques, which effectively deal with different parts of the printed structure. Substantial improvement is introduced to C-FFT by adding up the FFT tables before interpolating, which dramatically reduces the memory required to store the tables and accelerates the method-of-moment matrix filling time. The current on the antenna array and embedded element patterns (EEPs) are then rapidly obtained. Furthermore, an optimization method relying on sequential convex optimization and the fast full-wave scheme is proposed for the array synthesis. At each optimization iteration, EEPs are precomputed and assumed to be locally constant, which enables the implementation of convex programming to rapidly optimize the antenna positions. The EEPs are then quickly updated for the new antenna positions. The scheme enables the efficient inclusion of mutual coupling in array synthesis problems. Numerical results are presented and discussed for the synthesis of linear and planar arrays made of printed bowtie antennas.