Squegging - a phenomenon occurring in an oscillator, in which one or more oscillations stop for a certain time interval and then restart automatically, so that the operation is intermittent but repeatable, even for indefinitely long time. 1) 2)
Circuits which show this type of behaviour can be referred to as: squegging oscillator, squegger, self-quenching oscillator, or blocking oscillator.3)
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The effect occurs for instance because a DC bias shifts the operating point of a transistor into saturation which causes the oscillations to cease periodically.5) The bias then slowly reduces in the absence of oscillations, which can eventually resume, and the whole cycle restarts.
In a non-linear oscillator the most likely condition for squegging is if the Q value of the resonator is low and if the starting gain of the amplifier is much larger than necessary to ensure that oscillations occur. 6)
For the example electronic circuit shown in the image, squegging occurs only for fairly narrow set of parameters. For instance, it is enough to change the transistor to a different model, e.g. 2N2222 instead of 2N2369 for the oscillations to be continuous (i.e. without squegging).
However, the effect can be also used as a desirable feature. The character of oscillations can be used for instance for identification purposes7) or for RF communication as a super-regenerative oscillator.8)