| 摘要 |
<p>The receiver comprises a first amplifier (A1), a mixer (M) for downconverting a wanted communications channel, a second amplifier (A2), a demodulator (DM) and a microcontroller (MC) providing a digital gain setting for the second amplifier by means a digital gain control (AGC2) after a selection of the wanted communications channel, and providing an analog gain setting for the first amplifier by means of an analog gain control (AGC1) during demodulation of the wanted communications channel. The digital gain setting is in particular freezed during demodulation of the wanted communications channel and the microcontroller provides a re-calibration of the digital gain setting only, when the analog gain control is out of its control range. Applications are for example for direct conversion digital satellite receivers for reception of DVB-S, DVB-S2 or ABS-S television channels.</p> |
