Why Circuits Oscillate Spuriously, Part 2: Amplifiers
by Dennis L. Feucht
Innovatia Laboratories


In Part 1 of this article we examined spurious oscillations caused by parasitic reactances that form resonant circuits, and also resonances caused by impedance gyrations in the high-frequency (hf) region of operation of active devices. This second cause is not well known in the industry, but should be. This article continues with a practical example of how hf gyration theory can be applied to a pulse amplifier design. Then we consider how amplifier hf output inductance can resonate with output capacitance.

...download complete article here (312kb PDF file)
...download complete Part I here (127kb PDF file)

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