Optimized CAD of power amplifiers, for maximum added power or minimum third order intermodulation, using an optimization software coupled to a single tone source and load-pull set-up

Using the narrow-bandwidth approximation, the authors show that added power and third-order intermodulation can be approximated with a symmetrical source and load-pull single-tone measurement setup coupled with optimization software. This measurement setup has a completely symmetrical topology allowing simultaneous active source and load-pull. The device under test is loaded by 50 Omega at the harmonic frequencies. A rigorous calibration procedure was implemented and validated at low power levels by comparison with an HP 8510 network analyzer. The data acquisition software is described, and large-signal experimental results are given for a typical transistor.<>