> BBT News > Trade News

Trade News

How the satellite antenna works?


Satellite TV reception system is composed of: parabolic wimax antenna, feed, LNB, satellite receiver with a complete set of satellite receiving stations.

1, parabolic wimax antenna is the Star of the satellite signal energy reflected converged into a focal point.

2, feed is the focus of the parabolic wimax antenna Department set up a satellite signal fear speaker, called the feed, meaning that the source of feed energy, requests will gather to focus all the energy collected. Feedforward is basically a satellite dish feed with a large angle ripple.

3 LNB (LNB downconverter also known) is a satellite feed sent down the signal frequency and signal amplification and transmission to the satellite receiver. High-frequency noise in the first degree as low as possible.

4, the satellite receiver is the first high-frequency transmission to the satellite signal demodulation, demodulation of satellite TV image signal and audio signal.

Satellite TV signals of broadcasting polarization.

Polarization of satellite television signals have four: right-hand circular polarization, L circular polarization, vertical polarization and horizontal polarization. The first two are not commonly used due to polarization, vertical polarization is only introduced (V) and horizontal polarization (H) of the receiving mode.

Vertical polarization and horizontal polarization of the receiver, is to change the feed of the rectangle (rectangular) waveguide port to determine the direction of the received vertical polarization or horizontal polarization. When the rectangular waveguide parallel to the long side of the mouth of the ground to receive the vertical polarization. Perpendicular to the ground to receive the level of polarization. Polarization direction (polarization angle) to vary because of biased. Because the earth is a sphere, while the satellite downlink signal beam is horizontal straight line, which creates the different azimuth. Received the same polarization signals are different, different location, the received signal polarization is also biased. Long feed waveguide I (polarization direction) will not completely vertical or horizontal to the ground. Adjust the polarization direction should pay attention to this.

Come from: http://www.boboto.com.cn