Design of Microwave Active Devices

Appendix 6

Wideband Amplification: Parallel Resistive Feedback

Let us consider a two-port network with parallel feedback that consists of normalized impedance its normalized admittance matrix is expressed in its simple form as

So the scattering matrix of the two-port network with feedback is:

If we use the simplified model of the transistor as defined in section 1.5.3.2, the following results are obtained:

– Resistive feedback

In this case, y = g resistive.

The equations are expressed as:

Low-frequency matching is obtained when canceling S₁₁ and S₂₂ when p → 0.

Simultaneous matching is only possible if Z₀g_d 1.

Under these conditions:

As we report this condition in the equations, the low-frequency ...