Patent ID: 7289005

Claim:
A polar modulator comprising: a first signal input for supplying a phase modulation signal and a second signal input for supplying an amplitude modulation signal; a phase locked loop having a reference input, a control input, and an output node, wherein the reference input supplies a reference signal, the control input receives a loop control signal, wherein the loop control signal is at least partially derived from the phase modulation signal and wherein the phase locked loop is operable to emit a radio-frequency signal at one frequency at the output node, the one frequency being derived from the reference signal and from the loop control signal; a pulse width modulator having a signal input, a control input, and an output, wherein the signal input receives the radio-frequency signal, wherein the control input receives a regulation signal, and the pulse width modulator is operable to vary a duty ratio of the radio-frequency signal applied to the signal input according to the regulation signal to provide a phase-amplitude modulated signal at the output; and a filter arranged downstream from the output of the pulse width modulator for suppression of harmonic components of the phase-amplitude modulated signal.