New oscillator concept based on band edge degeneracy in lumped double‐ladder circuits

Abstract

An oscillator scheme based on the degenerate band edge (DBE) in a periodic, double-ladder resonant circuit made of lumped elements is proposed for the first time. The circuit exhibits a DBE in the dispersion diagram of its phase-frequency eigenstates and possesses unique resonance features associated with a high loaded Q-factor resonance, compared to a single-ladder circuit. This oscillator is shown to have an oscillation threshold that is half that of a single LC ladder circuit having the same total quality factor, and thus is more robust than an LC oscillator in the presence of losses. Moreover, the double-ladder oscillators have a unique mode selection scheme that leads to stable single-frequency oscillations even when the load is varied. It is also shown that the output amplitude of the double-ladder oscillator is much less sensitive to the output loading compared to single-ladder oscillators. The authors show the analysis and design of such oscillators that potentially lead to enhancing the efficiency of RF components and sources.