Study on Broadband Pulsed Surface Wave Oscillator with Double-Corrugation

研究了由双波纹构成的慢波结构的宽带脉冲表面波振荡器。表面波的频散特性可以通过波纹参数来控制。对20~40 GHz范围内的表面波进行了数值模拟和实验研究。弱相对论电子束是由盘式冷阴极产生的，而不是由热阴极产生的。通过将光束注入双波纹，在双波纹的基础上实现了强表面波激励和约20%的频率可调谐。数值模拟了基于双波纹高阶模式的高频运转，实验证明了较强的高阶模式辐射。此外，强表面波激发扩展到170 GHz频段。对于强宽带太赫兹波源，高阶和扩展的表面波操作是相当有意义的。

Broadband pulsed surface wave oscillators with slow-wave structure composed of double-corrugation are examined. The dispersion characteristics of surface wave can be controlled by the corrugation parameters. The surface waves in the range from 20GHz to 40GHz are examined numerically and experimentally. Weakly relativistic electron beams are generated by a disk type cold cathode, not by a hot cathode. By injecting the beam into the double-corrugation, an intense surface wave excitation and a frequency tunability of about 20 percent are demonstrated based on the double-corrugation. And high frequency operation based on the higher order modes of double-corrugation are examined numerically and relatively strong radiations of higher order mode are demonstrated experimentally. Moreover, the intense surface wave excitation is extended up to 170GHz-band. The higher order and extended surface wave operations are of considerable interest for an intense broadband terahertz wave source.