Electromagnetic waveform processing through time-modulated thin sheets

This paper explores advanced methods of electromagnetic (EM) waveform manipulation through temporally-modulated thin sheets. Two configurations are analyzed-a layer with time-varying (TV) conductivity and one with TV permittivity-to determine how temporal modulation of these parameters affects the transmission of incident EM pulses. Analytical and numerical approaches are formulated to solve the corresponding inverse problems, providing the required temporal profiles of material parameters for achieving user-defined transmitted waveforms. Several application examples are presented, including frequency mixing, time-domain (TD) pulse shaping, and spectral shaping, which demonstrate how dynamic control of a layer's conductance or capacitance can tailor the time-domain profile and spectral content of EM pulses. The results were validated using a commercial FEM code and show that a properly designed time variation of the layer's conductance or capacitance enables functions such as pulse compression, spectral reweighting, and generation of new frequency components, making such structures promising for advanced reconfigurable EM systems.