Analysis of the Characteristics of a Coaxial Gyrotron Cavity With a Tilted Inner Rod

The effects of the tilted inner rod of a coaxial gyrotron cavity on the resonant frequency, the diffractive quality factor, and the longitudinal field distribution for transverse electric (TE) modes are investigated. As a practical application, a numerical analysis is given to TE₆₂ mode in the 330-GHz wideband continuous frequency tunable coaxial gyrotron proposed by O. Dumbrajs´ group. Results show that a small tilt angle of the inner rod will cause a noticeable change in the resonant frequency, the diffractive quality factor, and the longitudinal field distribution for TE modes in a coaxial gyrotron cavity due to the mode coupling. The resonant frequency and the diffractive quality factor increase with increasing tilt angle of the inner rod; if the tilt angle θ is 0.4^°, the resonant frequency shift will be about 1.5 GHz.