Title :
Some Characteristics of a Stable Negative Resistance
Author :
Brunetti, Cledo ; Greenough, Leighton
Author_Institution :
Formerly, Assistant Professor of Electrical Engineering, Lehigh University, Bethlehem, Pa.; now, Radio Physicist, National Bureau of Standards, Washington, D.C.
Abstract :
By employing positive feedback in a two-stage amplifier it is possible to obtain an input impedance which is equal to the impedance in the feedback circuit multiplied by a negative constant. For a resistance-capacitance feedback circuit the input impedance becomes a negative resistance in series with a negative capacitance. With the proper choice of circuit constants, the negative impedance can be made to approximate closely a pure negative resistance over any given frequency range. In the apparatus described, high stability is secured by the use of inverse feedback in addition to the positive-feedback loop.
Keywords :
Capacitance; Electrical resistance measurement; Feedback circuits; Frequency; Impedance; Negative feedback; Output feedback; Tuned circuits; Voltage; Zinc;
Journal_Title :
Proceedings of the IRE
DOI :
10.1109/JRPROC.1942.233345
