Accession Number : AD0673716

Title :   IDEALIZED VERSUS OPERATIONAL RELIABILITY OF RF POWER TRANSISTORS AS DETERMINED BY INFRARED SCANNING TECHNIQUES.

Descriptive Note : Research and development technical rept.,

Corporate Author : ARMY ELECTRONICS COMMAND FORT MONMOUTH N J

Personal Author(s) : Hakim,Edward B. ; Reich,Bernard ; Malinowski,Gregory

Report Date : JUL 1968

Pagination or Media Count : 18

Abstract : Burn-out of power transistors is a continuing problem that we are all aware of. The problem is not only unique with audio devices but is also prevalent with devices for HF, VHF, and UHF operations. Limited technical information is available as to the conditions leading to the failure of RF power devices under operating conditions. By applying infrared scanning techniques, insight has been obtained on the mechanisms leading to failure. The infrared scanning results have proved, by means of operational amplifier results, that failures formerly noted can be eliminated, thus leading to trouble-free operations. The infrared radiometer used is commercially available. It has the potential of resolving a hot spot of 0.3 mils in diameter. RF hot-spot temperature measurements were made on several devices having different design parameters. Evaluation of devices was made by analysis of 'hot-spot' thermal resistance plots. Included are data of experiments made on devices under pulsed dc operation. Results from the operational amplifiers are then compared with the pulsed data. RF operational data is presented at both 30 MHz and 76 MHz. Data of various load terminations are presented and analyzed. From these results it has been possible to realistically rate RF power transistors to operate under nearly any load termination. (Author)

Descriptors :   (*TRANSISTORS, *RELIABILITY(ELECTRONICS)), (*INFRARED SCANNING, TRANSISTORS), (*FAILURE(ELECTRONICS), TRANSISTORS), TEST METHODS, MAPPING, TEMPERATURE, POWER, FEEDBACK AMPLIFIERS, RADIOMETERS, VERY HIGH FREQUENCY, CLASSIFICATION, THERMAL CONDUCTIVITY, SPECIFICATIONS, DIAGRAMS

Subject Categories : Electrical and Electronic Equipment
      Mfg & Industrial Eng & Control of Product Sys

Distribution Statement : APPROVED FOR PUBLIC RELEASE