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Selection for Wi-Fi Deployments

Topics:

. Antenna functionality . Antenna specifications . . Internal vs. external . Coverage patterns . Bridge links

1 Certified Network Professional Understanding Antennas

Electromagnetic Waves

Antennas radiate electromagnetic waves into the air

Antennas both radiate and receive electromagnetic waves. They radiate the waves as the electromagnetic signal escapes from the antenna. They receive waves as the energy is captured by the antenna.

2 Certified Professional Active vs. Passive

Amplifier

Passive gain uses no extra Active gain uses an RF to amplification and relies fully on increase the signal strength. The the directionality of the amplifier is placed in path between antenna for increased RF the AP and antenna or between energy in a desired direction. the and antenna.

3 Certified Wireless Network Professional SISO vs. MIMO

Single Input/Single Output Multiple Input/Multiple Output

4 Certified Wireless Network Professional dBi Gain compared to an (dBi)

-50 dB point

Isotropic Isotropic Radiator Radiator -48 dB point

2 dBi Antenna -50 dB point

5 Certified Wireless Network Professional Antenna Specifications

Key Specifications . Frequency . Resistance (Ohms) . Gain . Connector type . Beamwidth

6 Certified Wireless Network Professional RF Radiation Patterns

Patch Antenna Omni Antenna Internal AP Antenna

7 Certified Wireless Network Professional Antenna Charts

Elevation (Vertical) Azimuth (Horizontal)

8 Certified Wireless Network Professional Elevation and Azimuth Charts Illustrated

Azimuth (Horizontal) Elevation (Vertical)

9 Certified Wireless Network Professional Antenna Types

Omnidirectional Patch Dish Semi-Directional Highly Directional

10 Certified Wireless Network Professional Internal vs. External Antennas

Internal antennas work well for common office space deployments.

External antennas work well for coverage of large areas or when directionality is needed.

11 Certified Wireless Network Professional Environmental Impact on Radiation Patterns

Materials and objects in the environment will change the in actual space from that specified for the antenna.

12 Certified Wireless Network Professional WLAN Coverage Coverage factors: . Radiation patterns . Output power Warehouse Coverage . RF behaviors

Office Coverage

13 Certified Wireless Network Professional Outdoor Coverage

Semi-directional antennas are used in this case to radiate out from the building.

14 Certified Wireless Network Professional Bridge Links Factors: . . Required Data Rate . Link Quality

Free Space

Line of Sight Clearance

15 Certified Wireless Network Professional