Accession Number : AD0870212

Title :   Study of RF Modulated Crossed-Field Amplifiers.

Descriptive Note : Semi-annual rept. 20 Jun-19 Dec 69,

Corporate Author : RAYTHEON CO WALTHAM MA MICROWAVE AND POWER TUBE DIV

Personal Author(s) : Dudley, Kenneth W. ; Nichols, Lawrence J. ; MacPhail, Gilford R.

Report Date : MAY 1970

Pagination or Media Count : 61

Abstract : A study of rf modulated crossed field amplifiers (CFA), is being pursued in two areas: the ability of the CFA to be pulse modulated using rf drive power only (rf keying), and the instantaneous bandwidth capability of backward-wave devices. For the rf keying experiments, a special L-band forward-wave test vehicle was designed and built with a multi-section (5) cathode, each section insulated from the others. This design permits application of various bias voltages to different cathode sections to determine the optimum configuration for rf keying conditions. The design also permits measurement of the distribution of the current around the cathode as well as the power dissipated in different sections of the cathode and anode. Details of the tube construction are given in the report. Test results are also described for tests performed with a forward-wave tube having a single cutoff electrode which was biased at various voltage levels to achieve rf keying. Two S-band backward-wave CFA's were constructed for studies of instantaneous bandwidth capability, and a modulator was assembled for test equipment. Tube design characteristics and test data are presented, as is an analysis of the CFA-modulator interface that was examined to determine the characteristics that are influenced by very rapid frequency or rf phase changes. (Author)

Descriptors :   *CROSSED FIELD DEVICES), (*MICROWAVE AMPLIFIERS, RADIOFREQUENCY POWER, MODULATION, TRAVELING WAVE TUBES.

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE