DocumentCode :
946397
Title :
Unilateralization of Junction-Transistor Amplifiers at High Frequencies
Author :
Chu, G.Y.
Author_Institution :
Sylvania Elec. Prod., Inc., Electronics Div., Ipswich, Mass.
Volume :
43
Issue :
8
fYear :
1955
Firstpage :
1001
Lastpage :
1006
Abstract :
In designing an amplifier with a bilateral device, unilateralization is one approach which permits use of techniques already developed for unilateral devices, in particular vacuum tubes. A general method for deriving a unilateral circuit based on an equivalent circuit of the device is described, emphasis being placed on junction transistors operating at high frequencies. The principle is: application of external feedback which neutralizes the internal feedback of the device so that the signals at the output end no longer yield a signal at the input end. In general, two types of circuits are used for junction-transistor high-frequency amplifiers: emitter input and base input connections. Measurements of the input characteristics of two singly-tuned amplifiers have verified their unilateral properties. Tolerances of the neutralizing network depend on such factors as: transistor parameter spread, impedance level of the collector circuit, and performance deviations which a designer will accept. Gain and input and output characteristics of the unilateralized high-frequency amplifier may be predicted easily from the transistor parameters (both emitter input and base input connection) in a frequency range below the alpha cutoff frequency.
Keywords :
Broadband amplifiers; Circuits; Cutoff frequency; Electron tubes; Frequency response; Output feedback; Radio frequency; Radiofrequency amplifiers; Stability; Vacuum technology;
fLanguage :
English
Journal_Title :
Proceedings of the IRE
Publisher :
ieee
ISSN :
0096-8390
Type :
jour
DOI :
10.1109/JRPROC.1955.278209
Filename :
4055535
Link To Document :
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