$ \begin{aligned} \ &s_{12}=0.2 \angle-15^{\circ} \ &s_{21}=2.6 \angle 50^{\circ} \ &s_{22}=0.5 \angle-105^{\circ} \ \end{aligned} $ calculate and plot stability circles and choose $\Gamma_t$ for $\Gamma_{\text {in }}>>1$ Desigu load terminating network. (Io Marks)

Solution:

Stability checks -

$ \begin{aligned} \\ |\Delta| &=\left|s_{11} s_{22}-s_{12} s_{21}\right| \\\\ &=0.559\lt1 \\\\ k &=\frac{\left.|-| s_{11}\right|^2-\left|s_{22}\right|^2+|\Delta|^2}{2\left|s_{12} . s_{21}\right|}=0.2427\lt1 \\ \end{aligned}\\ $

As $k\lt1$ tiansistor is unstable $\&$ can be used to design oscillator.

Plotting of stability circles

$ \begin{aligned} \\ &C_S=\frac{\left(s_{11}-\Delta s_{22}^*\right)}{\left|s_{11}\right|^2-|\Delta|^2}=\frac{(0.9 L-150-0.559 \times 0.5\angle 105)}{0.9^2-0.559^2} \\\\ &\therefore C_S=\frac{1 …