A Generalized Scattering Parameters Analysis Method for Multiport-Fed Antennas and Amplitude-Phase-Controlled Arrays

In this communication, we propose a generalized scattering parameters (S-parameters) calculation method for multiport antennas and amplitude-phase-controlled arrays based on a multimode analysis approach. First, we detail the process for calculating passive multimode S-parameters for a multiport antenna element, using single-ended S-parameters and a multimode orthogonal matrix. This concept is then extended to amplitude-phase-controlled multiport antenna arrays. Specifically, we develop a generalized active S-parameter calculation method that accommodates arrays with varying amplitudes, phases, and excitation modes. To validate our proposed analysis methods, we design and simulate three antenna and array examples. By optimizing the multimode S-parameters, we achieve high-performance antennas and arrays while significantly simplifying the optimization process compared to traditional single-ended S-parameter methods. We believe our proposed analysis methods provide a robust foundation for designing multiport microwave components and amplitude-phase-controlled systems.