This calculator evaluates the gain uncertainty (or gain ripple) caused by reflections due to mismatches between the source, amplifier and load. It takes into account return losses, amplifier gain and reverse isolation to determine the minimum and maximum limits of the actual gain.
Formulas
P = 10 ((−RLs − RLi) / 20) + 10 ((G − RLl − RLs − ISO) / 20) + 10 ((−RLo − RLl) / 20)
Gmin = 20 × log10(1 − P)
Gmax = 20 × log10(1 + P)
Explanation of formulas
These formulas calculate possible variations in an amplifier’s gain due to internal and external reflections. Return losses (RL) determine the level of reflection between interfaces, while isolation (ISO) and gain (G) influence stability. The result gives Gmin and Gmax, the minimum and maximum possible gain values in dB.
Uses of the calculator
- Evaluation of the gain stability of an RF amplifier.
- Analysis of the effects of mismatches on the performance of RF circuits.
- Optimization of the design of amplifiers and transmission chains.
- Useful tool for RF engineers and microwave system designers.