Patent ID: 6366177
Filing Date: 2002-04-02
Classification: H03C,H03F

Abstract:
An RF power modulator, comprising:a three-port power amplifier having a signal input, a signal output, and a power supply input that is varied in a controlled manner; a modulator driver responsive to an information input for producing an input signal applied to the signal input of the three-port power amplifier and a controlled power supply source applied to the power supply input, wherein the modulator driver comprises a signal map responsive to an information signal for producing at least first and second quantities, a phase modulation signal generator responsive to at least one of the quantities for producing an input signal of the three-port power amplifier, and a magnitude controller responsive to at least one of the quantities for producing the controlled power supply source; means for producing a calibration factor derived from a measurement of at least one characteristic of an output signal of the three-port power amplifier, the calibration factor being applied to the modulator driver, causing at least one of the input signal and the controlled power supply source to be varied; wherein the three-port power amplifier is driven repeatedly between two states, a hard-on state and a hard-off state, without operating the amplifier in a linear operating region for an appreciable percentage of time, thereby producing an RF output signal, the modulator driver and the calibration circuitry operating in an open-loop manner with respect to the RF output signal.