VHF UHF microwave repeater-function of repeater at VHF,UHF
This page describes function of repeater used at VHF, UHF and microwave frequency range. It also provides link to wifi repeater and LTE repeater types.
Line of Sight Communications by direct wave is characteristic of most of the radio frequency signals with frequency of above 30 MHz approx. This is true for VHF, UHF and microwave frequencies. These signals will pass through ionosphere and will not bend. Transmission distances at these frequencies are very much limited. Moreover antenna height matters a lot to extend the distance coverage. Because of this reason, very high transmission antennas are used for FM and TV broadcasts.
As mentioned one way to increase the range of transmission and reception at high frequencies is to place the antenna on top of the tall buildings or on mountains. The other way is to use repeater in between transmitter and receiver. It is also known as repeater station.
VHF UHF repeater
The figure-1 depicts single repeater used to extend range of VHF/UHF communication.
Repeater consists of receiver, transmitter and antenna.
Let us understand function of repeater.
➨Repeater receives the signal from a transmitter.
➨Amplify the received signal.
➨Retransmit the signal on another frequency to the receiver.
Microwave repeater
The figure-2 depicts series of repeaters used to extend range of microwave communication. The classic example is microwave relay stations used by telephone companiesfor long distance communication.
Here functions of all the repeaters is same as mentioned above. A whole string of repeater stations can relay signals for larger distances. Typically, such relay stations are located at 20 to 60 miles apart. They are placed at high altitude to achieve reliable communication over long distances.
Repeaters are developed based on different technologies and frequency of use. For example, repeater developed for WLAN network is known as WiFi repeater and repeater developed for LTE network is known as LTE repeater. Refer WiFi repeater and LTE repeater.
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