Efficient Generation of High Power Microwaves using the Degenerate Band Edge Oscillators

We propose a novel scheme for efficient generation of high power microwaves exploiting a four-mode interaction principle ¹, ² occurring in slow-wave-structures (SWSs) with degenerate band edge (DBE). The DBE condition entails the coalescence of four slow-wave eigenmodes (both wavenumbers and eigenvectors) at the band edge in special types of periodic SWSs. Such principle of interaction offers a significantly lower starting oscillation electron beam current ¹, compared to conventional backward wave oscillators (BWOs), and also high power efficiency. We demonstrate the existence of the DBE in metallic SWS through cold structure measurements. The DBE enables unique dispersion characteristics as well as giant scaling of the quality factor that are fundamental for enhancing the performance of microwave sources. We demonstrate here for the first time high efficiency and high power generation using electron beam driven degenerate band edge oscillators (DBEO) in Sband.