Accession Number : ADA193792

Title :   Space-Charge-Wave Solid State Microwave Amplifier.

Descriptive Note : Final rept. Sep 86-Oct 87,

Corporate Author : AEROJET ELECTROSYSTEMS CO AZUSA CA

Personal Author(s) : Martin, B G

PDF Url : ADA193792

Report Date : 31 Dec 1987

Pagination or Media Count : 61

Abstract : This investigation was on the feasibility of a device utilizing the GaAs/AlGaAs HEMT structure for amplifying microwaves. The following accomplishments were made. (1) number of design considerations bearing on concept feasibility were investigated, e.g., carrier scattering losses, LO phonon creation, penetration depth of microwaves into HEMT structure, etc. Based on these considerations, the concept appears feasible; (2) Fabrication techniques were developed for interdigital electrode slow-wave circuits and ohmic contacts on HEMT structure; (3) Several prototype devices were fabricated and tested. A result of this was that coupling of microwaves (at GHz frequencies) to the HEMT channel electrons was demonstrated; and (4) Theoretical work showed that the TO phonons in doped GaAs behave as the 'resistive wall' necessary for electromagnetic wave amplification. In addition, an investigation was made on the interaction of electromagnetic waves and drifting electrons in a model of a HEMT structure. Amplifying instabilities are in evidence. It is concluded that the subject device appears feasible, but further and extensive experimental work is required. (Author)

Descriptors :   *AMPLIFICATION, *COUPLING(INTERACTION), *INTERACTIONS, *MICROWAVES, *PHONONS, *SLOW WAVE CIRCUITS, CHANNELS, DEPTH, DRIFT, ELECTRIC CONTACTS, ELECTRODES, ELECTROMAGNETIC RADIATION, ELECTRONS, FABRICATION, FEASIBILITY STUDIES, LOSSES, METHODOLOGY, PENETRATION, PROTOTYPES, SCATTERING, THEORY

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE