Title :
Exploration of a double-tapered disc-loaded circular waveguide for a wideband gyro-TWT
Author :
Kesari, Vishal ; Jain, P.K. ; Basu, B.N.
Author_Institution :
Center of Res. in Microwave Tubes, Banaras Hindu Univ., Varanasi, India
fDate :
3/1/2006 12:00:00 AM
Abstract :
The analysis of a disc-loaded circular waveguide interaction structure of a gyro-traveling-wave-tube (gyro-TWT) considering standing and propagating mode harmonics in the disc-occupied and disc-free regions, respectively, gave the beam-absent dispersion relation of the waveguide. The axial phase propagation constant predicted by the dispersion relation was substituted into the gyro-TWT gain-equation, the latter obtainable from the beam-present dispersion relation of the device. A method of double-tapering the structure dimensions was proposed that consists in tapering the disc-hole radius to distribute the midband frequency of amplification over a wide range of frequencies, and simultaneously tapering the waveguide-wall radius to compensate for gain reduction at band edges due to disc-hole radius tapering. The method has demonstrated wide device bandwidths at relatively large gain values.
Keywords :
circular waveguides; gyrotrons; millimetre wave amplifiers; travelling wave amplifiers; travelling wave tubes; wideband amplifiers; axial phase propagation constant; circular waveguide interaction structure; disc-hole radius tapering; disc-loaded waveguide; dispersion relation; gyro-traveling wave tube; harmonics; millimeter-wave amplifier; waveguide-wall radius; Bandwidth; Dispersion; Electromagnetic waveguides; Frequency; Millimeter wave communication; Millimeter wave radar; Millimeter wave technology; Structural discs; Tellurium; Wideband; Disc-loaded waveguide; millimeter-wave amplifier; periodic electromagnetic structure; wideband gyro-traveling-wave-tube (gyro-TWT);
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2005.864176