Antenna Installation

Notes for Antenna Installation:

•A. Installation environment

-The installation environment includes the surroundings near the antenna and near the base station. The surroundings near the antenna mainly consider the isolation between antennas, and the influence of iron towers and buildings on antennas; the surroundings near  the base station mainly consider the influence of high buildings lower than 500 meters along the  radio signal transmission.

 

•During the installation of base station antennas, it is required to notice whether they may lead to big shadow in the coverage area, and to kept away from obstacle, for example, in the installation of antennas on the top of a building, you should make sure no obstacle against radio signal on the top, and try to install the antennas near the edge.

 

•B. Antenna Isolation

-The receiver and transmitter of the base station shall be isolated in a certain degree;

-Isolation between antennas: The attenuation of signals from one port of an antenna to that of the other one in actual installation of antenna;

-GSM system: The isolation between two transmitting antennas and between the transmitting and receiving antennas shall be 30dB at least;

.  Antenna vertical layout: Lv=28+40log(k/λ)(dB) about 50cm (900Mhz)

•Antenna horizontal layout: Lv=22+20log(d/λ)-(G1+G2)-(S1+S2)(dB)

»About 10 * wavelength (900Mhz)

 

•C. Meet the distance requirements for space diversity gain

-For space diversity, the distance between two receiving antennas is required to be 12～18λ;

-The higher the antenna is installed, the bigger the horizontal distance between diversity antennas is; normally, the diversity horizontal distance shall be equal 0.11 time of the effective height of the antenna;

To reduce the inter influence of two antennas, the diversity antenna horizontal distance at any effective height of antenna shall  be over 3m.  

 

 

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