Floquet Analysis of Space-Time Modulated Metasurfaces With Lorentz Dispersion

A rigorous semianalytical Floquet analysis is proposed for modeling space–time-modulated metasurface and determining the scattered fields in terms of their harmonic components. The method based on generalized sheet transition conditions (GSTCs) treating a as spatial discontinuity with zero thickness. described Lorentzian electric magnetic surface susceptibilities, both tangential normal to surface, parameters (e.g., resonant frequency) that are periodically modulated space time. unknown expressed harmonics, which amplitudes can be found by numerically solving set linear equations, leading total fields. Using existing computational techniques commercial full-wave solver, validated using several examples pure-space pure-time modulation different strengths pumping frequencies. Finally, two cases space–time (standing wave perturbation traveling-wave perturbation) presented demonstrate breaking Lorentz reciprocity. simple versatile able determine steady-state response excited an oblique plane or general incident field such Gaussian beam.