Ultra-wideband BWO with waveguide loaded grating

This paper presents a solution for a tunable broadband terahertz radiation source, which can be realized by a newly designed BWO (Backward Wave Oscillator) using slow-wave structure with dual waveguide-loaded gratings. Gratings in two rows of the same height operate in different frequency ranges. Additionally, the signal-to-noise ratio within the operating frequency has been dramatically improved by placing a lossy material at the end of the waveguide. The operating frequency of the double gratings alternate from 185.63 GHz to 239.6 GHz and 244.08 GHz to 291.93 GHz accordingly. Ultimately, the relative bandwidth of the whole device reaches 41.7%.