A proposed 4 GHz, 60 kW transit-time oscillator operating at 18 kV beam voltage

Author

Barroso, Joaquim J. ; Kostov, Konstantin G. ; Yovchev, Ivailo G.

Author_Institution

Assoc. Plasma Lab., Nat. Inst. for Space Res., Brazil

Volume

26

Issue

5

fYear

1998

fDate

10/1/1998 12:00:00 AM

Firstpage

1520

Lastpage

1525

Abstract

A high-power transit-time oscillator operating at 4.0 GHz in the cylindrical-cavity TM₀₁₀ mode is proposed. Without requiring an externally applied magnetic field, the oscillator comprises a diode electron gun and a cylindrical cavity that are combined into a single unit that makes for a compact, lightweight device. The transit-time effect, which underlies the operation principle of the oscillator, is examined through a small-signal analysis from which a relation embodying the cavity length, resonant frequency, and cathode voltage is derived. Proper DC voltages of 18 kV are applied to the diode gun which runs in the space-charge-limited regime and produces a 27 A-current hollow electron beam. Output power is extracted axially from the system by aperture coupling the cavity to an external waveguide where outgoing travelling waves with 60 kW peak power are observed by means of 2.5 D particle-in-cell computer simulations

Keywords

microwave oscillators; transit time devices; 18 kV; 2.5 D particle-in-cell computer simulations; 4 GHz; 60 kW; DC voltages; aperture coupling; beam voltage; cathode voltage; cavity length; cylindrical cavity; cylindrical-cavity TM₀₁₀ mode; diode electron gun; diode gun; external waveguide; externally applied magnetic field; hollow electron beam; operation principle; outgoing travelling waves; output power; peak power; resonant frequency; small-signal analysis; space-charge-limited regime; transit-time effect; transit-time oscillator; Apertures; Cathodes; Diodes; Electron beams; Magnetic analysis; Magnetic fields; Power generation; Resonant frequency; Voltage; Voltage-controlled oscillators;

fLanguage

English

Journal_Title

Plasma Science, IEEE Transactions on

Publisher

ieee

ISSN

0093-3813

Type

jour

DOI

10.1109/27.736053

Filename

736053