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一、概述卫星电视接收机是卫星地面接收站的室内单元,与天线、微波下变频器相配合,用来接收卫星转发的电视信号,经过第二变频、频道选择、中放解调以及基带信号处理,从中还原出视频图像及伴音信号;或转换成VHF或UHF频段的AM电视信号,送到普通电视接收机进行收看. 卫星电视接收机在卫星地面收转系统中,通常有个体接收、集体接收和地面转发接收三种方式.图1、图2、图3分别是这三种接收方式的示意图.个体接收方式中,接收机收到的信号,直接用监示器或普通电视机收看,这种方式仅适用于在极小范围内收看.对于集体接收方式,接收机收到的信号通过CATV系统,使更多用户收看到卫星电视信号.在地面转发接收方式中,接收机输出的图像及伴音信号通过电缆送到地面演播中心控制台视频及音频输入接口,经控制台切换可通过电视发射机或微波中继机等转换出去.
I. Overview Satellite TV receiver is the satellite ground receiving station indoor unit, with the antenna, microwave down converter to be used to receive satellite-transmitted television signals, after the second frequency conversion, channel selection, demodulation and baseband signal Processing, from which to restore the video and audio signals; or converted into VHF or UHF band AM television signals, sent to ordinary television receivers to watch satellite television receivers in the satellite ground transfer system, usually individual receiving, collective Receiving and terrestrial forwarding receive three ways Figure 1, Figure 2, Figure 3, respectively, these three kinds of receiving schematic diagram of the individual receiving mode, the receiver receives the signal directly to the monitor or ordinary TV to watch, This approach is only suitable for viewing in a very small range .For the collective reception mode, the signal received by the receiver through the CATV system, so that more users to watch satellite television signals.In terrestrial transmission mode, the receiver output images And audio signals sent through the cable to the ground studio console video and audio input interface, the console can be switched by TV transmitter or microwave repeater conversion go with.