Gain Circles - Part II — Lesson 6

This lesson explains how to use the gain circle for bilateral and unilateral case design. It also covers the limitations of the bilateral case, and the concept of maximum gain. The lesson also discusses the conditions for unconditionally stable and potentially unstable cases, and how to design using operating power gain and available power gain. It provides an illustrative example of designing an amplifier where the output impedance is fixed but the input impedance can be varied.

Video Highlights

01:38 - Bilateral matching
08:18 - Explanation of the maximum stable gain.
13:53 - Operating power gain circles .
18:43 - Draw the operating power gain circle for a given Gp .
20:39 - Design for potentially unstable case
23:26 - Design using available power gain circles

Key Takeaways

- The bilateral case of microwave integrated circuit design offers less flexibility than the unilateral case.
- For unconditionally stable cases, it's possible to specify the maximum gain achievable.
- For potentially unstable cases, a simultaneous match doesn't exist, making the design process more complex.
- Operating power gain and available power gain can be used for designing RF circuits.
- The design process involves selecting a particular value of operating power gain, choosing a point on the gain circle, and calculating the corresponding input and output reflection coefficients.