IQ MODULATION SYSTEM AND METHODS THAT USE SEPARATE PHASE AND SIGNAL PATHS

摘要

PROBLEM TO BE SOLVED: To provide IQ modulation systems and methods that can provide high power modulation while reducing the amount of battery power that is consumed since wireless communications terminals continue to decrease in power consumption.

SOLUTION: A digital signal processor generates in-phase, quadrature-phase and amplitude signals from a baseband signal. A modulator modulates the in-phase and quadrature-phase signals to produce a modulated signal. A phase locked loop is responsive to the modulated signal. The phase locked loop includes a controlled oscillator having a controlled oscillator input. An amplifier includes a signal input, an amplitude control input and an output. The signal input is responsive to the controlled oscillator output and the amplitude control input is responsive to the amplitude signal. The phase locked loop that is responsive to the modulated signal includes a controlled oscillator output and a feedback loop between the controlled oscillator input and the controlled oscillator output. The feedback loop includes a mixer that is responsive to a local oscillator.

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