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Potentially unstable devices

In the case of potentially unstable devices, there is no maximum gain design because maximum gain implies a gain of infinity, in order words, oscillation. A potentially unstable device is a device which has input and output reflection coefficients greater than unity for certain source and load terminations. We can find the regions of these source and load terminations by means of input and output stability circles. In the design, we should try to keep the source and load terminations from these regions as far as possible for a high degree of stability. The design process is very often an iterative process because the source and load terminations affecting each other for a non-unilateral device.