Wireless Networks- Lecture 6

Wireless Networks
Lecture 6: Antenna Considerations

Antenna job is both to:
* Transmit a signal as well as shape.
* Focus a received signal so that it can be understood.

Radiation Pattern
There are many types of antennas they all have a radiation pattern. That pattern indicates the power radiated in any direction relative to the direction of maximum radiation.

Although the actual radiation pattern of any antenna is a three-dimensional function, When we work with pen and paper the pattern is specified in terms of a two dimensional diagram.
This two-dimensional pattern illustrates the beam pattern of the antenna with respect to a 360-degree
Note that most of the antenna’s radiated power is concentrated in a narrow beam. Also note that the concentric circles radiating outward from the center of the circle indicate the signal strength.

Beam Width
Beam Width describes how the signal radiates from an antenna and is expressed in degrees horizontally and vertically. For example, an omnidirectional antenna radiates its signal 360 degrees horizontally. It depends on the model; it might have as much coverage area as 75 degrees vertically. As such, it doesn t radiate its signal in a complete sphere around the antenna. Rather, it s more of a donut shape.