Dielectric Lens Antenna Size Reduction Due to the Shape Optimization with Genetic Algorithm and Muller Boundary Integral Equations

We study a two-dimensional (2D) homogeneous dielectric lens typical for mm and sub-mm wave applications and used to improve the radiation properties of printed antennas or other types of primary sources. We have developed a new computer aided design and optimization tool based on the Muller boundary integral equations and a genetic algorithm. A favorable feature of this algorithm is its guaranteed accuracy and high efficiency in terms of computer time and resources that is achieved due to the use of integral-equation solver as an engine in the optimization routine. Numerical results are presented for a rexolite lens fed by a line source located close to the lens flat bottom. Lens profile is characterized with cubic splines whose node coordinates are optimized to provide the best possible directivity of the source. Both E- and H-polarizations are considered. We demonstrate nontrivial field behavior in small-size dielectric lenses and highlight possible bottlenecks in their numerical synthesis