General description
The direct conversion QPSK demodulator is the front-end receiver dedicated to digital TV broadcasting, satisfying both DVB-S and DBS TV standards. The wide range oscillator (from 950 MHz to 2175 MHz) covers the American, European and Asian satellite bands, as well as the SMA-TV US standard. The Zero-IF (ZIF) concept discards traditional IF filtering and intermediate conversion techniques. Gain-controlled amplifiers in the RF guarantee optimum signal level. The variable gain is controlled by the signal returned from the Satellite Demodulator and Decoder (SDD) and applied to pin AGC.