High Power Backward Wave Oscillator using Folded Waveguide with Distributed Power Extraction Operating at an Exceptional Point

TL;DR

This paper introduces a novel backward wave oscillator design leveraging exceptional point degeneracy to significantly boost output power and efficiency at millimeter-wave frequencies, surpassing traditional limitations.

Contribution

It presents a new degenerate synchronization regime using folded waveguide with distributed power extraction, achieving high power and efficiency at 88.5 GHz.

Findings

Output power exceeds 3 kW

Conversion efficiency exceeds 20%

Operates effectively at 88.5 GHz

Abstract

The concept of exceptional point of degeneracy (EPD) is used to conceive a degenerate synchronization regime that is able to enhance the level of output power and power conversion efficiency for backward wave oscillators (BWOs) operating at millimeter-wave and Terahertz frequencies. Standard BWOs operating at such high frequency ranges typically generate output power not exceeding tens of watts with very poor power conversion efficiency in the order of 1%. The novel concept of degenerate synchronization for the BWO based on a folded waveguide is implemented by engineering distributed gain and power extraction along the slow-wave waveguide. The distributed power extraction along the folded waveguide is useful to satisfy the necessary conditions to have an EPD at the synchronization point. Particle-in-cell (PIC) simulation results shows that BWO operating at an EPD regime is capable of generating output power exceeding 3 kwatts with conversion efficiency of exceeding 20% at frequency of 88.5 GHz.