Particle swarm optimization of the tapered slot antenna for wideband scanning E-plane linear array

Paper describes a novel way to optimize the unilateral tapered slot antenna (TSA) being an element of a wideband scanning E-plane linear array. Taper profile of the antenna is mathematically represented as a piecewise linear function. Particle swarm optimization algorithm is implemented to find the coordinates of piecewise linear profile following the purpose to minimize the active reflection coefficient of TSA in a scanning array environment. Active reflection coefficient down to –15 dB is theoretically achieved for TSA in E-plane linear array operating over the most part of frequency band 5–10 GHz and scanning sector ±30°. The proposed design approach is validated by experimental investigations of two linear array test samples with fixed main lobe directions at 0° and 30° respectively. Each test sample is composed from eight similar TSA elements with the optimized piecewise linear profile. Arrays are excited by the 8-way microstrip power divider of corporate type with microstrip true time delay lines at the outputs that provide required wideband phasing of radiating elements