Signal Amplification in Time-Modulated RF Components with Infinite Superluminality

Abstract

Wave propagation in time-varying media is a hot topic at the moment due to the exotic properties the wave experiences, such as magnetless non-reciprocity, parity-time symmetry, and topological aspects. When the speed of modulation exceeds the speed of light in a media (superluminal regime), momentum gaps appear in the real frequency dispersion diagram. Only complex frequencies exist within these gaps with positive values (causing wave growth) and negative values (causing wave decay) imaginary parts. If the media is pure-time modulated (infinite superluminality), signal amplification happens at 0.5 wave/modulation frequency ratio <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(F_{s}/F_{m})$</tex>. Here, we present signal amplification modeling of time-modulation RF components, transmission line (TL) and cavity resonators. The transmission matrix method is utilized to get the dispersion relations which confirmed by circuit modeling transient simulations.