Analysis of a Gyro-TWT in a Cylindrical Waveguide with a Dielectric Lining on its Wall

Abstract

The cold as well as hot dispersion relation for a gyro-TWT employing a cylindrical waveguide loaded with a dielectric lining on its wall was obtained. An improved approach was given where the effect of dielectric loading was incorporated in the deduction of the hot dispersion relation rather than in an earlier approximate approach where the effect had been considered only in the deduction of the cold dispersion relation. The hot dispersion relation was used to obtain Pierce-type gain expression. The dielectric lining with optimally chosen permittivity and thickness values provided an improvement with respect to the gain as well as bandwidth of the device as compared to a dielectric-free, unloaded device. The gain-frequency responses predicted by the approximate and improved approaches differed more as the permittivity and the thickness of the dielectric lining increased, though the other relevant device parameters like the optimum beam position for maximum gain did not appreciably differ.

Additional information

Notes on contributors

Ashutosh Pandey

Ashutosh Pandey was born in Kanpur, India, on April 12, 1980. He is a final year student of Bachelor of Technology in Electronics Engineering at the Institute of Technology, Banaras Hindu University, Varanasi, India.

His research interests include fast and millimeter wave vacuum electron devices, device modeling, besides speech processing. He has published six research papers in various national and international journals and conference proceedings.

Sharad Kumar

Sharad Kumar is completing his Bachelor of Technology course in Electronics Engineering at the Institute of Technology, Banaras Hindu University, Varanasi, India. His areas of research interest are modeling of microwave tubes and digital circuit design. He has authored and presented research papers in various national conferences. He is recipient of the “Malviya Technology Talent Award 1999” at the Institute of Technology for technical excellence.

P K Jain

P K Jain received BTech degree in Electronics Engineering, and MTech (with gold medal) and PhD degrees in Microwave Engineering, all from the Banaras Hindu University, Varanasi, India, in 1979, 1981, and 1988, respectively.

In 1981, he joined the Centre of Research in Microwave Tubes, Department of Electronics Engineering, Institute of Technology, Banaras Hindu University, as a Lecturer, and is currently working there as a Reader. The areas of his current research and publication include CAD/CAM and modeling of microwave tubes and their subassemblies, including broadbanding of helix traveling-wave tubes (TWTs), cyclotron resonance maser devices, including gyro-TWTs and their performance improvement. He is Principal Investigator of a government-sponsored project. He is a Fellow of the Institution of Electronics and Telecommunication Engineers (India).

B N Basu

B N Basu received MTech and PhD degrees from the Institute of Radiophysics and Electronics, Calcutta University, India in 1966 and 1976, respectively. Currently, he is working as Professor at the Centre of Research in Microwave Tubes, Electronics Engineering Department, Banaras Hindu University, Varanasi. He was associated with Central Electronics Engineering Research Institute, Pilani, as a Distinguished Visiting Scientist / Short-Term Consultant. He was seconded by CSIR and British Council to work at the University of Lancaster, UK under an academic-link program. He is recipient of S V C Aiya Memorial Award of IETE. He is member of the Technical Committee on Vacuum Devices of IEEE Electron Devices Society. His areas of current research and publications include helix-TWT modeling, broadbanding of TWTs, synthesis of electron guns and gyro-TWT amplifiers. He has authored a book entitled Electromagnetic Theory and applications in Beam-Wave Electronics (World Scientific, Singapore, 1996).