Patent ID: 8391352
Filing Date: 2013-03-05
Classification: H03L,H04N

Abstract:
1. A low cost ATSC digital television modulator compatible with ATSC television receivers, comprising: a crystal oscillator circuit; a Weaver modulator circuit connected to the crystal oscillator circuit; and a digital-to-analog conversion circuit connected to the Weaver modulator, wherein the crystal oscillator circuit comprises: a crystal oscillator for producing a first frequency output; a first frequency-division circuit connected to the crystal oscillator first frequency output for producing a first base frequency output at a first fraction of the frequency of the crystal oscillator; and a second frequency-division circuit connected to the crystal oscillator first frequency output for producing a local-oscillator step frequency output at a second fraction of the frequency of the crystal oscillator; a third frequency-division circuit connected to the local-oscillator step frequency output for producing a second base frequency output at a first fraction of the frequency of the local-oscillator step frequency output; a first frequency multiplier circuit connected to the local-oscillator step frequency output for producing output video channel frequencies in steps according to the local-oscillator step frequency; and a second frequency multiplier circuit connected to the local-oscillator step frequency output for producing local oscillator channel frequencies in steps according to the local-oscillator step frequency; and a third frequency multiplier circuit connected to the second base frequency output for producing an MPEG-2 frequency output at a multiple of the frequency of the second base frequency output.