The New Jersey Institute of Technology's
Electronic Theses & Dissertations Project

Title:	Theory and design of cyclotron-wave traveling-wave amplifiers
Author:	Gottfried, Arthur H.
View Online:	njit-etd1979-010 (251, A1-A14 pages ~ 6.5 MB pdf)
Department:	Department of Electrical Engineering
Degree:	Doctor of Engineering Science
Program:	Electrical Engineering
Document Type:	Dissertation
Advisory Committee:	Whitman, Gerald Martin (Committee chair) Klapper, Jacob (Committee member) Rosenstark, Sol (Committee member)
Date:	1979-10
Keywords:	Amplifiers, Traveling-wave. Cyclotron waves.
Availability:	Unrestricted
Abstract:	A theory and design procedure for traveling-wave tubes using cyclotron-wave interactions is developed. An analysis is presented of the energy exchange mechanism and the axial beam velocity spread induced by the r.f. interactions. The analysis of the energy spread in a realistic model of the beam with nonzero size and nonzero space-charge density shows that higher maximum efficiencies at higher power is attainable (with collector depression) in cyclotron-wave amplifiers than in synchronous-wave amplifiers. A one-watt, and a ten-watt cyclotron-wave amplifier at 3 GHz, utilizing bifilar helix circuits, scaled from a 2 kW, 5 GHz design, were constructed. A computer was used to design a pitch taper for the circuit of the ten-watt tube to maintain synchronism between beam and circuit waves so as to enable the extraction of more energy from the beam. In general, test results verify the theory, and indicate the possibility of attaining efficiencies of the order of 70% in a 2 kW, 5 GHz cyclotron-wave amplifier. Because of the relatively low interaction impedance available for transverse-wave interactions, it is estimated that gains of the order of 1 dB/inch are possible.