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Terrestrial Microwave TK2133 A103418 Lee Hau Sem A103411 Lai Horng Meau What is Terrestrial Microwave ?

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Terrestrial Microwave


A103418 Lee Hau Sem

A103411 Lai Horng Meau

what is terrestrial microwave
What is Terrestrial Microwave ?
  • transmission systems consisting of at least two radio transmitter/receivers (transceivers) connected to high gain antennas (directional antennas which concentrate electromagnetic or radio wave energy in narrow beams) focused in pairs on each other.
  • The operation is point-to-point-communications are established between two and only two antennas with line-of-sight visibility.
  • This can be contrasted to point-to-multipoint systems like broadcast radio or television.
how terrestrial microwave transfer and receive data
How Terrestrial Microwave Transfer and Receive Data
  • Terrestrial microwave communication employs Earth-based transmitters and receivers to transfer and receive data.
  • The frequencies used are in the low-gigahertz range, which limits all communications to line-of-sight.
  • Example of terrestrial microwave equipment -telephone relay towers, which are placed every few miles to relay telephone signals cross country.
antenna that use to transfer data
Antenna That Use to Transfer Data
  • Microwave transmissions typically use a parabolic antenna that produces a narrow, highly directional signal.
  • A similar antenna at the receiving site is sensitive to signals only within a narrow focus.
  • Because the transmitter and receiver are highly focused, they must be adjusted carefully so that the transmitted signal is aligned with the receiver.


An Antenna is :

An effective interface between the radio and free space:

Free space


For Terrestrial Communications, antennas must be directional:


formula parabolic antenna directive gain
Formula Parabolic AntennaDirective Gain

Ga (dBi) = 10 log10h [ 4 p Aa / l2 ]


Ga = Antenna Directive Gain (Catalog spec)

h = Aperture Efficiency (50-55%)

Aa = Antenna Aperture Area

l= Wavelength (speed of light / frequency)


Typical ParabolicAntenna Gain in dBi

Antenna Diameter



Standard Parabolic Antenna

  • Basic Antenna
  • Comprised of
    • Reflector
    • Feed Assembly
    • Mount
terrestrial microwave antennas for point to point communication
Terrestrial Microwave Antennas for Point-To-Point Communication
  • Terrestrial microwave antennas generate a beam of RF signal to communicate between two locations.
  • Point-To-Point communication depends upon a clear line of sight between two microwave antennas.
  • Obstructions, such as buildings, trees or terrain interfere with the signal.
  • Depending upon the location, usage and frequency, different types can be utilized.
  • We will address the basic characteristics of these various types…
the use of microwave link
The Use of Microwave Link
  • A microwave link frequently is used to transmit signals in instances in which it would be impractical to run cables.
  • If you need to connect two networks separated by a public road,
  • for example, you might find that regulations restrict you from running cables above or below the road. In such a case, a microwave link is an ideal solution.
ability to connect with other devices
Ability To Connect With Other Devices
  • Some LANs operate at microwave frequencies at low power and use unidirectional transmitters and receivers.
  • Network hubs can be placed strategically throughout an organization, and workstations can be mobile or fixed.
  • This approach is one way to enable mobile workstations in an office setting.
frequencies that use by terrestrial microwave
Frequencies That Use By Terrestrial Microwave
  • In many cases, terrestrial microwave uses licensed frequencies.
  • A license must be obtained from the FCC, and equipment must be installed and maintained by licensed technicians.
frequencies that use by terrestrial microwave13
Frequencies That Use By Terrestrial Microwave
  • Terrestrial microwave systems operate in the low-gigahertz range, typically at 4-6 GHz and 21-23 GHz, and costs are highly variable depending on requirements.
  • Long-distance microwave systems can be quite expensive but might be less costly than alternatives. (A leased telephone circuit, for example, represents a costly monthly expense.)
  • When line-of-sight transmission is possible, a microwave link is a one-time expense that can offer greater bandwidth than a leased circuit.
advantages of terrestrial microwave over satellite
Advantages of Terrestrial Microwave over Satellite
  • Lower cost
    • Avoid exorbitant costs of leasing satellites (unless satellites are already owned by the customer)
  • Reduced latency
    • Video is delivered with minimal delay. Satellite signals must travel significantly further with an average delay of 250 milliseconds for signals to travel to a geo-satellite and return to earth (this excludes video processing delay).
advantages of terrestrial microwave over satellite15
Advantages of Terrestrial Microwave over Satellite
  • Increased Flexibility
    • BMS terrestrial systems are easily reconfigurable for different power levels and frequencies.
    • BMS terrestrial systems are mobile and easily deployed wherever coverage is needed. Multiple satellites may need to be utilized for all the required coverage areas.
    • Video can be captured using light weight, mobile equipment in difficult-to-reach areas. Video can also be captured by moving aircraft, ships, and vehicles.
    • Aircraft with BMS digital microwave for line-of-sight (LOS) communications can also be equipped with a satellite tracking antenna for beyond-line-of-sight (BLOS) satellite communications when needed.
advantages of terrestrial microwave over satellite16
Advantages of Terrestrial Microwave over Satellite
  • Reduced Size & Weight
    • The RF link operates over a shorter distance and requires less power than a satellite equivalent. Lower power means less weight, smaller size and reduced power consumption.
    • Ground-based systems can use a tracking antenna for higher gain. Higher antenna gain results in lower transmit power requirements. This is less practical for satellite mounted antennas.