Tunability and switching of Fano and Lorentz resonances in PTX-symmetric electronic systems

Abstract

Resonance is a ubiquitous phenomenon observed in a wide range of physical systems. Recently, with the Fano resonance exerting remarkable potential for optical, acoustic, atomic, and electronic applications, it is vital to control and even dynamically reconfigure the resonance line shape and bandwidth, in addition to its frequency. In this work, we introduce a parity-time-reciprocal scaling (PTX)-symmetric structure, which can offer a promising avenue for tailoring the resonance frequency and line shape of electronic circuits. We have theoretically studied the resonance behavior of such a PTX-symmetric electronic system, particularly for dependencies of resonant peaks and line-shapes on the non-Hermiticity, coupling coefficient, and the scaling coefficient introduced by the reciprocal scaling (X) transformation. Our results demonstrate that, at resonance frequencies, a transition between Fano and Lorentzian line-shapes is possible with a specific reciprocal scaling rule applied to lumped-element circuits.