A communication system composed of microwave sending machines, receiving machines, heavenly feedback systems, multi -way reuse equipment and user terminal equipment. Microwave communication system, using microwave communication has a large capacity, good quality, and can be passed to a long distance. Therefore, it is an important communication method for the National Communications Network, which is …
What is the main role of the trunk amplifier? What are its classification, characteristics, main technical indicators and their calculation? What kind of relationship exists between the carrier-to-noise ratio and the nonlinear index? The main function of a trunking amplifier is to. To offset the amount of attenuation of the signal by the transmission medium …
Satellite TV receiving systems mainly include antenna, feedback, high -frequency head, and satellite receiver. The parabola satellite antenna receives the feed signal focused on the front end of the satellite high frequency head, and converted to the C frequency (3.7GHz ~ 4.2GHz) signal or KU frequency band (11.7 ~ 12.75GHz) signal. out. Digital TV signals …
Interference and measures of satellite TV receiving signals Read More »
I. Features of Ku-band satellite digital broadcasting. Compared with the previous C-band satellite analogue broadcasting, Ku-band satellite digital broadcasting has its outstanding features due to the use of higher frequency Ku-band and advanced digital compression technology. 1、Main features of Ku-band satellite broadcasting. (1) Ku-band satellite single transponder power is generally larger, more fugitive beam coverage, …
The images and sounds received by the TV are transmitted by radio waves. During the spread of radio waves, the TV receiving signal is weak if it is blocked by tall objects. In order to prevent tall objects from blocking the radio waves, the TV launch antenna is generally more outdoors. Pay attention to lightning …
The full name is Multichannel Microwave Distribution System . MMDS was originally used for terrestrial transmission of one-way TV and Internet broadcasting. It is a complete set of transmitting and receiving systems, which belong to the DVB-T standard. As a part of the MMDS receiving system, the MMDS downconverter belongs to the ground wave receiving …
At 21:18 on September 13, the China Star 1E satellite developed by the Fifth Academy of Aerospace Science and Technology Group was successfully launched on the Long March 7A carrier rocket at the Wenchang Space Launch Site in Hainan. Then the satellite successfully entered the predetermined orbit, and the launch mission was a complete success. …
470-862MHz Yagi Antenna Yagi Antenna Definition It is an end-fire antenna composed of an active vibrator, a passive reflector and several passive directors arranged in parallel. In the 1920s, this kind of antenna was invented by Yagi Shuji and Uda Tailang of Tohoku University in Japan, which is called “Yagi Uda Antenna”, or “Yagi Antenna” …
Precautions when we install the antenna Whether the satellite TV receiving antenna is erected on the ground or on the building, the location selection is a primary link. We must fully consider the local natural environment and electromagnetic environment. The basis for selecting the location includes: the field strength of the satellite signal, the interference …
When we choose place to install antenna, do you know what to pay attention to? Read More »
The car antenna is also called the car antenna. Generally, the antenna on the car is used for the radio and radio on the car. It can be divided into the built-in antenna and the external antenna of the car. However, there are other antennas installed in the car according to different purposes. If the …
When the radio waves pass through the area of rain, the rain not only absorbs the energy of the radio waves, but also scatters the radio waves. This absorption and scattering together form the attenuation of radio waves. Scattering can also lead to large-scale radio interference and has a depolarizing effect on the radio waves. …
According to the structure shape, can be divided into single-polarized split(LNB) and double feed integration (LNBF) two kinds, including bipolar feed integration HF head more types, according to the oscillation mode can be divided into single oscillation and dual oscillation two kinds. According to the output port can be divided into single output, dual output, …
Introduction to the types and parameters of LNBF Read More »
