Patent ID: 7539462

Claim:
A configurable multi-mode modulation system for use in a transmitter, comprising: a phase modulation path receiving a phase component converted from base band data and frequency modulating the phase component to generate a frequency modulated RF signal on an output; a first selectable amplitude modulation path receiving an amplitude component converted from base band data and, when the first selectable amplitude modulation path is selected, modulating the amplitude component to generate a first amplitude modulated signal on an output; a combiner circuit having a first input, a second input and an output coupled to a power amplifier, wherein the first input is coupled to the output of the phase modulation path and the second input is coupled to the output of the first selectable amplitude modulation path, the combiner circuit selectively outputting a first combined signal derived from the frequency modulated RF signal or a second combined signal derived from the first amplitude modulated signal and the frequency modulated RF signal; a second selectable amplitude modulation path coupled to the converter for receiving the amplitude component and, when the second selectable amplitude modulation path is selected, converting the amplitude component to a second amplitude modulated signal on an output, wherein the first and second selectable amplitude modulation paths are not selected when the modulation system is operating in GMSK modulation; and a configurable stage having a first input coupled to the output of the second selectable amplitude modulation path, a second input suitable for receiving a feedback signal from an output of the power amplifier, and an output suitable for coupling to a power control input of the power amplifier, wherein, when the second selectable amplitude modulation path is selected, the configurable stage is configured as an integrator for comparing the second amplitude modulated signal and the feedback signal to generate a power control signal on its output, thereby providing amplitude modulation to the power amplifier.