Characterization of Modulated Metasurface Using Multibit, Uniform and Non-uniform Quantization

Abstract

This work proposes a novel statistical approach for quantizing a circularly polarized modulation metasurface antenna (MMSA), aiming to replace dynamically varying unitcell dimensions with a fixed set of subwavelength meta-unit elements. Both uniform and non-uniform discretization techniques are numerically evaluated and integrated into the MMSA design to identify the most suitable method, ensuring minimal trade-offs with key performance parameters. Initially, single- and multi-bit uniform discretization techniques are employed. To overcome their performance limitations, a nonuniform quantization approach is subsequently modeled and implemented through full-wave electromagnetic (EM) simulation. The proposed non-uniform quantization utilizes a power-law-based cumulative distribution function (CDF) combined with selective clustering which effectively reduces the number of unique quantization levels compared to the initial theoretical design. The numerical distribution is validated using full-wave EM simulation by evaluating all key parameters of a circularly polarized (CP) MMSA consisting of 50×50=2500 meta unit-cells.