An enhanced active load-pull system for highly mismatched power transistor measurements

A novel load-pull technique is proposed which is shown to be very efficient and accurate for the characterization of highly mismatched power devices resulting from multichip association. The technique consists in performing fine and accurate electronic load perturbations around initial mismatches. The associated measurement system is capable of measuring high-power, low-impedance (several watts, 1 Omega ) power devices. Measurement results on silicon bipolar power transistors are given. This technique is particularly well suited for the measurement of very-high-power transistors (several tens of watts) under continuous-wave or pulsed mode operation.<>