Cavity-Excited Metagrating Antennas with Controlled Frequency Diverse Patterns

We present a semianalytical approach to design frequency diverse cavity-excited antennas, using metagratings (MGs, sparse arrays of subwavelength scatterers). Harnessing the reliable frequency response prediction of the underlying analytical model, tying the MG parameters to the waveguide eigenmode composition at the aperture, a single MG design that radiates prescribed (significantly different) patterns at different frequencies is obtained. This systematic method and resultant devices, validated via full-wave simulations, could find use in mm-wave imaging systems and emerging security schemes.