Patent ID: 7940142
Filing Date: 2011-05-10
Classification: H03C,H03L

Abstract:
1. A two-point modulation phase-locked loop (PLL) for use in a polar transmitter, comprising: a first input coupled to receive a phase signal of a variable-envelope modulated signal and coupled to provide the phase signal along a first signal path to produce a first frequency modulation signal; a second input coupled to receive the phase signal and coupled to provide the phase signal along a second signal path to produce a second frequency modulation signal, the first and second frequency modulation signals being produced by differentiation of the phase signal; and a voltage controlled oscillator having a first modulation point as a first oscillator input directly coupling the voltage controlled oscillator to the first signal path to receive the first frequency modulation signal and a second modulation point as a second oscillator input directly coupling the voltage controlled oscillator to the second signal path to receive the second frequency modulation signal; and a summation node implemented within the voltage controlled oscillator, wherein the summation node comprises: wherein the voltage controlled oscillator is controlled by an aggregate of the first frequency modulation signal and the second frequency modulation signal to up-convert the phase signal from an intermediate frequency (IF) to a radio frequency (RF) to produce an RF signal; wherein the voltage controlled oscillator has a first gain associated with the first modulation point and the second modulation point has a second gain associated therewith, and wherein the second gain is substantially matched to the first gain by adjusting the second gain external to the PLL.