Broadbanding a gyro-traveling-wave tube by chiral-dielectric material loading

ABSTRACT

Loading the circular waveguide interaction structure of a gyro-traveling-wave tube (gyro-TWT) with chiral material was proposed to show the possibility of widening the device bandwidth. Outlines to obtain the dispersion relation of a circular waveguide enveloping a chiral-dielectric rod and a chiral-dielectric tube were presented, which further interpreted in special cases for the circular waveguides loaded with a chiral-dielectric coaxial rod (structure I) and with a chiral-dielectric wall-lining (structure II). A computer code was developed in MATLAB to solve the dispersion relations and the solutions were substituted into the Pierce-type small-signal gain equation of a gyro-TWT for the device-gain calculation. The electromagnetic analysis of the structure has been validated against simulation. The dispersion shaping and the broadbanding were presented for the two structures. The structure I was found to be more sensitive to chirality parameter than structure II.

KEYWORDS:

• Millimeter-wave tube
• gyro-traveling-wave tube
• dielectric loaded structure
• fast-wave structure

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Vishal Kesari

Vishal Kesari received M. Sc. (Physics) degree from Purvanchal University, India, and Ph. D. (Electronics Engineering) degree from Institute of Technology, Banaras Hindu University (IT-BHU) (now known as IIT-BHU), India, in 2001 and 2006, respectively. He has worked as Research Fellow at Centre of Advanced Study, Electronics Engineering Department, IT-BHU and significantly contributed to sponsored research projects at Centre of Research in Microwave Tubes, IT-BHU. He served as Lecturer at Birla Institute of Technology, Ranchi, India, and Indian Institute of Information Technology, Allahabad, India, before joining as Scientist at Microwave Tube Research and Development Centre, Defence Research and Development Organisation, Bengaluru, India. His research interest includes microwave and millimeter-wave vacuum electronic devices. He has authored two books: (i) Analysis of Disc-loaded Circular Waveguides for Wideband Gyro-TWTs (Lambert Academic Publishing AG & Co., Germany, 2009), and (ii) High Power Microwave Tubes: Basics and Trends (IOP Concise Physics; Morgan & Claypool Publishers, USA, 2018), and numerous research papers in peer-reviewed journals and conference proceedings. He has to his credit a number of international and departmental-level awards. He has acted as reviewers for various peer-reviewed journals and conference proceedings. He is a fellow of Institution of Electronics and Telecommunication Engineers (IETE), India, and a life member of Vacuum Electronic Devices and Application Society (VEDAS), India.

J. P. Keshari

J. P. Keshari received B. Tech. (Electronics and Communication Engineering) degree from Uttar Pradesh Technical University, Lucknow, India, M. Tech. (Instrumentation and Control Engineering) degree from Sant Longowal Institute of Engineering and Technology, Longowal, India, and Ph. D. (Electronics and Communication Engineering) degree from Sharda University, Greater Noida, India, in 2004, 2007 and 2017, respectively. He was an Assistant Professor at the Noida Institute of Engineering and Technology College, Greater Noida, India, and at Galgotia College of Engineering and Technology, Greater Noida, India. Currently, he is an Associate Professor at ABES Engineering College, Ghaziabad, India. His research interest includes microstrip patch antenna and waveguide structures for gyro-traveling-wave tubes. He has a number of research papers in peer-reviewed journals and conference proceedings. He has received a best teacher award at the Noida Institute of Engineering and Technology, Noida, India, and Galgotia College of Engineering and Technology, Greater Noida, India. He has acted as a reviewer for various peer-reviewed journals and conference proceedings. He is a Fellow of Institution of Electronics and Telecommunication Engineers (IETE), India.