Quantifying External Noise Properties of Time-varying Receivers Using Cross-frequency Effective Aperture

Recently, interest has grown throughout the antennas, propagation, acoustics, and optics communities on the exotic behaviors afforded by systems incorporating time-varying sub-systems, such as continuously time-varying dielectric materials and circuit components, switched devices, and moving media (Hayran and Monticone, IEEE APM 2023). Exploration of these components within antennas and microwave circuits in particular has led to many interesting and novel effects not obtainable from traditional linear time-invariant (LTI) devices. However, with these performance gains and novel behaviors, questions naturally arise as to whether there are potential negative consequences of adopting time-varying design strategies.