A method and apparatus for maintaining approximately constant gain of an RF power amplifier includes a digital control module for modifying gain parameters of the power amplifier to provide a constant fixed power gain over the entire frequency range of operation. The digital control module compares stored frequency response parameters, which are indicative of the inherent closed-loop gain of the power amplifier, with the current selected gain and carrier frequency setting to generate a digital gain control value. The digital gain control value is used to modify a detected input RF envelope in the power amplifier analog loop. The modified input envelope is compared with an envelope of the transmitted RF signal to adjust the gain of the power amplifier. Optionally, the detected RF input envelope may be sampled to digitally compensate for variations in the RF input signal.