Efficient Numerical Synthesis of Radiation Patterns Using Circuit Model for Substrate Integrated Waveguide Leaky Wave Antennas

A novel approach is presented for synthesizing radiation patterns of substrate-integrated waveguide leaky wave antennas in two stages. In the first stage, the antenna is considered an equivalent rectangular waveguide with slots, and a comprehensive equivalent circuit model is constructed. Varying slot configurations are accommodated by the developed equivalent circuit model. Each slot section is represented as an admittance with the incorporation of Elliott's slot theory. Computations of the relative aperture fields are performed using circuit theory, and the far-field pattern is estimated through array theory. In the second stage, the circuit model is utilized for genetic algorithm-based optimization, enabling customization of the radiation pattern to meet specific requirements. The methodology has a computational advantage over full-wave simulations, resulting in a significantly faster and more efficient design process. Numerical verification through simulation of various examples and experimental validation through antenna fabrication are presented, affirming agreement between calculated and measured results. Remarkable effectiveness in antenna engineering can be attained for future wireless communication systems by using the proposed technique.