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.