LOW-NOISE L-BAND AMPLIFIER.
Abstract
Work on single-stage and three-stage transistor amplifier design and construction is described. Commonbase measured Y parameters on recent L-78A devices are presented. The possibility of using common emitter is being reviewed because of recent improvements in device performance. The gain of the single-stage amplifiers is now relatively predictable from measured Y parameters, using the Linvill charts. The commonbase L-78A transistors give typically 8 to 13 db of gain at about 1.3 Gc with -3 db bandwidths ranging from 400 to 110 Mc in a microstrip circuit. The noise figures of the single stages are 4.5 to 5 db. The minimum corrected noise figure varies with load: the lowest measured noise figure occurs when the gain is highest. This variation with load is not in agreement with theory, and the cause of this variation is being investigated. A three-stage amplifier breadboard has been constructed which meets the gain-bandwidth design objectives. The noise figure is 5.8 db, in good agreement with the calculated value of 5.5 db. Phase shift on the amplifier will be measured when a phase measurement test set now on order is delivered. Earlier measurements using borrowed equipment have indicated that this will not be a severe problem. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 28, 1965
- Accession Number
- AD0616331
Entities
People
- George D. Johnson
- Leslie W. Read
- R. L. Petritz
- Roger R. Webster
Organizations
- Texas Instruments