Analytic parameter determination for thermal memory effect compensation circuit in microwave InGaP/GaAs HBT power amplifiers

An analytical design method based on Volterra series including both electrical effects and thermal effects is presented for compensating thermal memory effects in microwave power amplifiers. By using an electrical memory-effect-generation circuit consisting of a multi-stage RC ladder network, the thermal memory effect is directly canceled. Analytical formulas for this canceling condition and circuit parameters have been successfully derived. The validity of the proposed analytical method has been shown for an InGaP/GaAs HBT power amplifier operating at 1.95 GHz. The analytical design results are in good agreement with measured results.