Full-Wave Optimization of Linear, Edge Slot Array with Flare and Choke for Decreased Vertical Beamwidth and Cross-Polarization

A method is presented in this paper to rigorously analyze and design a linear edge slot array with appendages attached to the external structure. The analysis method is a finite element boundary integral (FE-BI) method that uses a spectrum of two-dimensional solutions to compute the boundary integral terms. Full array optimization is performed by iteration to obtain slot dimensions that produce the desired aperture distribution. Since the optimization attempts to control the slot electric fields directly, side lobe levels within a few dB of ideal results are obtained. A flare with a choke is proposed to control the vertical beamwidth and cross-polarization. Results for an optimized 75-slot array are given and discussed and good corroboration of the data is obtained with Ansoft's HFSS