A New Method to Test and Design Multistage Power Amplifiers Using Load Pull Data

As an alternative to designing single or two-stage power amplifiers using transistor models, non-linear load pull data can be used to characterize transistors when designing amplifiers. The input, output, and interstage matching networks can then be chosen and modified to optimize any parameter included in the load pull data. Parameters which can be measured and optimized include output power, efficiency, intermodulation, ACPR, harmonic load information, and many others. This new technique has the advantages of being very accurate, extremely fast, and is transistor independent. All that is required for rapid optimization of the amplifier design are the transistor S-parameters and swept input power load pull data over the entire load impedance range.