Invention Grant
- Patent Title: Dynamic adjustment to preserve signal-to-noise ratio in a quadrature detector system
- Patent Title (中): 动态调整以保持正交检测器系统中的信噪比
-
Application No.: US09022069Application Date: 1998-02-11
-
Publication No.: US06751272B1Publication Date: 2004-06-15
- Inventor: Lawrence M. Burns , Ravi Ramachandran , David Fisher , Chong Woo , Scott Mitchell
- Applicant: Lawrence M. Burns , Ravi Ramachandran , David Fisher , Chong Woo , Scott Mitchell
- Main IPC: H03D100
- IPC: H03D100

Abstract:
In a system that demodulates a frequency modulated signal using a quadrature detector circuit, an apparatus that tunes the output signal to compensate for any offset in the signal includes an offset adjustment circuit and a control circuit. The offset adjustment circuit is operably coupled to the control circuit which may consist of a DAC and a digital logic such as a computer CPU. The control circuit determines a correction signal in response to a sequence of sampled of the system output, and supplies the correction signal to the offset adjustment circuit. The offset adjustment circuit provides an offset correction signal in response to the correction signal, and combines the offset correction signal with the output of the quadrature detector to provide an offset adjusted signal at an output node.
Information query