A New Junction Transistor High-Frequency Equivalent Circuit
- Creators
- Middlebrook, R. D.
Abstract
A small-signal equivalent circuit for a junction transistor is presented which is applicable to alloy or grown types of p-n-p or n-p-n transistors, and which is valid from d-c up to twice the cutoff frequency. The equivalent circuit is in the form of four short-circuit admittances, each of which can be represented by a simple network of lumped elements constant with frequency. The derivation is based on physical principles and takes into account base widening and collector barrier capacitance. Equations for the equivalent circuit element values are given either in terms of physical parameters or in terms of six practical measurements. The four-admittance representation is given both for common-emitter and common-base connections, and a relation between the common- emitter and the common-base cutoff frequencies is derived and experimentally verified. Measurements of the real and imaginary parts of the four admittances as functions of frequency for several transistors show excellent agreement with the values predicted by the equivalent circuit.
Additional Information
This work was performed in part at Stanford University under Office of Naval Research Contract N6onr 251(07) (NR 373 360). The author wishes to thank Dr. J. M. Pettit, Dr. G. S. Bahrs, Dr. R. M. Scarlett, and K. G. Sorenson, all of Stanford University, for valuable assistance and discussion. The work was completed at the California Institute of Technology under Air Force Office of Scientific Research Contract AF 18(600)-1113. The numerical values in Table I were obtained by R. L. Walker at the Stanford Electronics Laboratories, and are part of a larger series of measurements used by him to verify a rather more accurate expression for the cutoff frequency of the common-base practical transistor than that given in (111). Figures 7 through 10 are reproduced by kind permission of John Wiley and Sons, Inc.Attached Files
Submitted - TR000390.pdf
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Additional details
- Eprint ID
- 98804
- Resolver ID
- CaltechAUTHORS:20190923-144144455
- Air Force Office of Scientific Research (AFOSR)
- AF 18(600)-1113
- Office of Naval Research (ONR)
- NR 373 360
- Created
-
2019-09-23Created from EPrint's datestamp field
- Updated
-
2019-10-03Created from EPrint's last_modified field
- Caltech groups
- Caltech Antenna Laboratory
- Series Name
- Caltech Antenna Laboratory Technical Report
- Series Volume or Issue Number
- 9
- Other Numbering System Name
- ASTIA
- Other Numbering System Identifier
- AD 120 469