Folded waveguide traveling-wave tube sources for terahertz radiation

Author

Bhattacharjee, Sudeep ; Booske, John H. ; Kory, Carol L. ; Van der Weide, Dan W. ; Limbach, Steve ; Gallagher, S. ; Welter, John D. ; Lopez, Mike R. ; Gilgenbach, Ronald M. ; Ives, R.Lawrence ; Read, Michael E. ; Divan, Ralu ; Mancini, D.C.

Author_Institution

Dept. of Electr. & Comput. Eng., Univ. of Wisconsin, Madison, WI, USA

Volume

32

Issue

3

fYear

2004

fDate

6/1/2004 12:00:00 AM

Firstpage

1002

Lastpage

1014

Abstract

Microfabricated folded waveguide traveling-wave tubes (TWTs) are potential compact sources of wide-band, high-power terahertz radiation. We present feasibility studies of an oscillator concept using an amplifier with delayed feedback. Simulations of a 560-GHz oscillator and experimental evaluation of the concept at 50 GHz are presented. Additionally, results from various fabrication methods that are under investigation, such as X-ray lithography, electroforming, and molding (LIGA), UV LIGA, and deep reactive ion etching are presented. Observations and measurements are reported on the generation of stable single-frequency oscillation states. On varying the feedback level, the oscillation changes from a stable single-frequency state at the threshold to multifrequency spectra in the overdriven state. Simulation and experimental results on amplifier characterization and dynamics of the regenerative TWT oscillator include spectral evolution and phase stability of the generated frequencies. The results of the experiment are in good agreement with the simulations.

Keywords

LIGA; feedback amplifiers; feedback oscillators; microwave amplifiers; microwave generation; microwave oscillators; plasma filled waveguides; sputter etching; submillimetre waves; travelling wave amplifiers; travelling wave tubes; 50 GHz; 560 GHz; LIGA; UV LIGA; X-ray lithography; amplifier characterization; deep reactive ion etching; delayed feedback; electroforming; fabrication methods; feedback level; microfolded waveguide traveling-wave tube sources; molding; multifrequency spectra; oscillator concept; oscillator simulations; overdriven state; potential compact sources; regenerative TWT generated frequencies; stable single-frequency oscillation states generation; wide-band high-power terahertz radiation; Broadband amplifiers; Character generation; Delay; Etching; Fabrication; Oscillators; Stability; State feedback; Wideband; X-ray lithography; Delayed feedback oscillator; FWG; TWT; folded waveguide; frequency spectrum; high power; microfabrication; phase; terahertz radiation; traveling-wave tube; wide-band;

fLanguage

English

Journal_Title

Plasma Science, IEEE Transactions on

Publisher

ieee

ISSN

0093-3813

Type

jour

DOI

10.1109/TPS.2004.828886

Filename

1321261