Patent ID: 7072633
Filing Date: 2006-07-04
Classification: H03D,H03L

Abstract:
1. A double-conversion tuner, comprising: an input for receiving an RF signal having a number of channels; a first mixer configured to up-convert said RF signal to a first IF signal using a first local oscillator signal; a first local oscillator having a delta-sigma fractional-N phase lock loop to produce said first local oscillator signal, said delta-sigma fractional-N phase lock loop configured to perform fine tuning of said first local oscillator signal and configured to have a wide tuning range sufficient to cover said number of channels, and said delta-sigma fractional-N phase lock loop including a bandpass filter configured to select a subset of channels from said first IF signal; a second mixer configured to down-convert said subset of channels to a second IF signal using a second local oscillator signal; and a second local oscillator configured to generate said second local oscillator signal, and configured to perform coarse frequency tuning and have a narrow tuning range relative to said first local oscillator.