IQ modulation systems and methods that use separate phase and amplitude signal paths

摘要

A modulation system comprising: a digital signal processor that generates in-phase, quadrature-phase and amplitude signals from a baseband signal; a modulator that modulates the in-phase and quadrature-phase signals to produce a modulated signal; a phase locked loop that is responsive to the modulated signal, the phase locked loop including a controlled oscillator having a controlled oscillator output; and an amplifier having a signal input, an amplitude control input and an output, wherein the signal input is responsive to the controlled oscillator output and the amplitude control input is responsive to the amplitude signal.