The design and implementetion of TV tuner for digital terrestrial broadcasting

DTV tuner for 8-VSB modulation was developed with satisfying the requirements of ATSC. The double frequency conversion and the active tracking filter in the front-end were used for the cancellation of the interferences between adjacent channels and multi-channels by suppressing IF beat and image band. However, it was impossible to get frequency mapping between tracking filter and first VCO in the existing DTV tuner structure differing from NTSC tuner. This paper, therefore, suggests the available structure and a new method for automatic frequency selection by obtaining the mapping of frequency characteristic over tracking voltage and the combined H/W which is composed of Micro-controller, EEPROM, D/A, OP amp. and switch driver.