An RF power amplifier module can be used without a matching device between
the power amplifier module and an antenna. The power amplifier module is
constructed and operated to detect, protect and maintain the performance
of the power amplifier in the presence of severe VSWR load mismatches,
without requiring the use of external circuitry. The RF power amplifier
module includes integral detection circuitry for generating a first
detection signal having a value that is indicative of the current flowing
through an output power transistor and a second detection signal having a
value that is indicative the voltage appearing at the output of the
output power transistor, as well as integral compensation circuitry for
controlling the generation of a plurality of bias current and bias
voltage signals to have values that are a function of the values of the
first and second detection signals, as well as the current output power
level of the RF power amplifier module. Also included is an integral
impedance matching circuit, coupled between the output of the output
transistor and the output node, that provides a variable impedance that
is selectively controlled by an output signal from the compensation
circuitry.