A low-power, high-efficiency Ka-band TWTA

Author

Curren, A.N. ; Dayton, J.A., Jr. ; Palmer, R.W. ; Force, D.A. ; Tamashiro, R.N. ; Wilson, J.F. ; Dombro, L. ; Harvey, W.L.

Author_Institution

NASA Lewis Res. Center, Cleveland, OH, USA

fYear

1991

fDate

8-11 Dec. 1991

Firstpage

581

Lastpage

584

Abstract

The authors describe a NASA-sponsored program whose objective is to develop a high-efficiency, low-power TWTA (traveling wave tube amplifier) operating at 32 GHz and meeting the requirements for the Cassini Mission to study Saturn, planned for launch in 1995. The required RF output power of the helix TWT is 10 W, while the DC power from the spacecraft is limited to about 30 W. This performance level will permit the transmission to Earth of all the data produced in the mission. In order to achieve this efficiency, several novel technologies are incorporated into the TWT, including an advanced dynamic velocity taper characterized by a nonlinear reduction in pitch in the output helix section of the TWT and a Lewis-designed multistage depressed collector using copper electrodes treated for secondary electron emission suppression. Preliminary program results are encouraging: RF output power of 10.6 W has been obtained at 14-mA beam current and 5.2-kV helix voltage with overall TWT efficiency exceeding 40%.<>

Keywords

microwave amplifiers; power amplifiers; travelling-wave-tubes; 10.6 W; 14 mA; 30 W; 32 GHz; 40 percent; 5.2 kV; Cassini Mission; DC power; EHF; Ka-band; Lewis-designed multistage depressed collector; NASA-sponsored program; RF output power; TWTA; beam current; dynamic velocity taper; efficiency; helix TWT; helix voltage; high-efficiency; low-power TWTA; nonlinear reduction in pitch; output helix section; secondary electron emission suppression; slow-wave devices; spacecraft link; transmission to Earth; traveling wave tube amplifier; Copper; Earth; Meeting planning; Power amplifiers; Power generation; Radio frequency; Radiofrequency amplifiers; Saturn; Space technology; Space vehicles;

fLanguage

English

Publisher

ieee

Conference_Titel

Electron Devices Meeting, 1991. IEDM '91. Technical Digest., International

Conference_Location

Washington, DC, USA

ISSN

0163-1918

Print_ISBN

0-7803-0243-5

Type

conf

DOI

10.1109/IEDM.1991.235403

Filename

235403