07015738 is referenced by 23 patents and cites 9 patents.

Techniques for direct modulation of a voltage-controlled oscillator (VCO) with adaptive digital gain control for wideband wireless applications are disclosed. A digital adaptive gain control loop is used to directly modulate the VCO, and a phase-locked loop (PLL) to track the frequency drift and other nonlinear effects of the VCO. As the PLL is applied to track the carrier frequency without passing the modulation signal into the PLL loop filter, the PLL can be implemented with a narrow loop bandwidth. The wideband frequency modulated signal is directly up-converted to the radio frequency (RF) signal by directly modulating the VCO through a digital-to-analog converter which is digitally controlled by an adaptive gain control loop. Thus, both wide bandwidth and low output noise for a frequency synthesizer and modulator can be achieved.

Title
Direct modulation of a voltage-controlled oscillator (VCO) with adaptive gain control
Application Number
10/871850
Publication Number
7015738 (B1)
Application Date
June 17, 2004
Publication Date
March 21, 2006
Inventor
Weixun Cao
Cupertino, 95014
CA, US
Agent
Joe Zheng
IPC
H03L 7/00
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