TV tuner

TV tuner

  • CN 102,761,719 B
  • Filed: 10/24/2007
  • Issued: 01/20/2016
  • Est. Priority Date: 10/25/2006
  • Status: Active Grant
First Claim
Patent Images

1. a TV tuner, comprising:

  • One radio frequency selects band filter, in order to receive a radiofrequency signal and this radiofrequency signal divided into the first frequency band signals and the second frequency band signals, the part that wherein this radiofrequency signal medium frequency is less than 450MHz is the first frequency band signals, and the part that this radiofrequency signal medium frequency is greater than 450MHz is the second frequency band signals;

    One first local oscillator, produces one first group of reference signal of a fixed frequency;

    One resonance frequency suppresses frequency mixer, is converted to one first intermediate-freuqncy signal according to this first group of reference signal by this first frequency band signals or this second frequency band signals;

    One second local oscillator, produces one second group of reference signal of frequency-adjustable;

    One first image-reject mixer, makes the carrier wave of a specific channel be converted to a first frequency according to this second group of reference signal by this first intermediate-freuqncy signal being converted to one second intermediate-freuqncy signal;

    One the 3rd local oscillator, produces one the 3rd group of reference signal of frequency-adjustable;

    AndOne second image-reject mixer, is converted to a second frequency according to the 3rd group of reference signal by being converted under this second intermediate-freuqncy signal under a low intermediate frequency signal makes the carrier wave of this specific channel;

    Wherein, this first frequency is greater than this second frequency, and the frequency of this first intermediate-freuqncy signal is greater than the frequency of this first frequency band signals and the frequency of this second frequency band signals, and the frequency of this second intermediate-freuqncy signal is greater than the frequency of this first intermediate-freuqncy signal.

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