Patent ID: 7072626

Claim:
A method of generating a radio frequency output signal based on polar modulation, the method comprising: generating a phase-modulated signal responsive to an input phase-modulation information signal; generating the output signal by imparting envelope-modulation to the phase-modulated signal responsive to an input envelope-modulation information signal; measuring an adjacent channel power ratio (ACPR) for the output signal by feeding back a portion of the output signal via a feedback circuit that generates a baseband measurement signal, detecting an envelope of the baseband measurement signal over a first bandwidth to obtain a first detection signal, and detecting an envelope of the baseband measurement signal over a second bandwidth to obtain a second detection signal, and obtaining an ACPR measurement signal by subtracting the second detection signal from the first detection signal; and controlling a relative delay between the phase-modulated and envelope-modulated information signals to reduce the measured ACPR.