1
\$\begingroup\$

Given a general microwave amplifier circuit Amplifier circuit

For this amplifier (transistor) to be stable the the magnitude of the input and output reflection coefficient must be smaller than 1.

Stability conditions

But why? What is an intuitive explanation for why the magnitude of the input and output reflections need to be smaller than 1 for this amplifier to be stable?

\$\endgroup\$
1
\$\begingroup\$

Reflection coefficient is the ratio, reflected/transmitted. If your input refection coef. is >1, you could supply the amp with 1 watt and have 2 watts reflected back out to the input port. If it continues to reflect back and forth, with the magnitude increasing with each reflection, you have an oscillation.

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.