Accession Number : AD0638195

Title :   MEASUREMENTS OF NONLINEARITIES IN A TRAVELING WAVE TUBE.

Descriptive Note : Research rept. (Technical).

Corporate Author : CHALMERS UNIV OF TECHNOLOGY GOTEBORG (SWEDEN) RESEARCH LAB OF ELECTRONICS

Personal Author(s) : Lindstrom,J. I.

Report Date : 01 JUN 1966

Pagination or Media Count : 31

Abstract : Measurements of the nonlinear amplitude distortion and phase shift in a TWT are reported. The test object is a commercial 1 W, S-band, O-type TWT with a helical slow wave structure. An extensive set of output amplitude and phase data were recorded for a wide range of input powers and helix voltages. The results are in good qualitative agreement with a recent nonlinear field theory developed by Nilsson. The best helix voltage settings in order to obtain minimum distortion in amplitude and phase respectively are located on opposite sides of the voltage that gives maximum small signal gain. This fact, which is theoretically well founded, is a complication in such applications where demanding specifications concerning amplitude and phase linearity must be met simultaneously. The measured nonlinearities are about three or four times larger than theoretical predictions. This discrepancy deserves a thorough investigation since it indicates that there is a margin for improving the tube design from the distortion point of view. (Author)

Descriptors :   (*TRAVELING WAVE TUBES, PHASE DISTORTION), S BAND, HELIXES, ELECTRON BEAMS, ELECTROMAGNETIC RADIATION, PHASE SHIFT CIRCUITS

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE