Rectangular Grating Slow-Wave Structure With a Slot Embed Electron Beam for High-Power Terahertz Radiation

To enhance the output power of 0.5-Terahertz (THz) backward wave oscillator (BWO), a grating loaded rectangular waveguide (GLRW) slow-wave structure (SWS) with a slot embed electron beam (SEEB) is proposed in present work. For the designs and optimizations of BWO GLRW SWS with SEEB, the dispersion equations are derived with a field matching method (FMM) and solved by a numerical method; the results show that the coupling impedances are remarkably enhanced. Moreover, the output performances are studied with a help of particle-in-cell (PIC) simulation, and the simulated results show that the BWO operation voltage is 25 kV and the current is 40 mA; the output power 18.9 W of the perfect electronic conductor SWS with SEEB is obtained, which is improved about 1.5 times. On the other hand, the time of start oscillation is decreased to 50%, which is compared with that the conventional SWS without slot. As for the THz vacuum electronic devices (VED), the amplitudes of output power are remarkably affected by the conductivity and roughness of SWS; therefore, the determinate factors are studied, and the PIC results show that the maximum power is about 5–7 W when the conductivity is 3– <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$5\times10$ </tex-math></inline-formula> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup> S/m. The proposed scheme affords a promising option for the developing of high-power THz source.