User's Manual

Table Of Contents

Introduction ORiNOCO Series System Recommended Antennas

Antenna Types

Wireless radios generate signals on a given frequency. Antennas distribute that signal through the air in a particular

pattern. Antennas take a given power output and make it reach further by reducing directions along which the signal is

radiated. Concentrating the signal on your workspace makes better use of your wireless radio’s power output. Stations

inside your workspace get stronger coverage and, therefore, higher speed. Directing the signal where you want it also

means less signal where you don’t want it; stations outside your workspace get little or no coverage.

Directional antennas (omni, sector, parabolic, flat) provide maximum range, but due to their narrow beamwidth, these

antennas require precise antenna alignment to achieve optimal performance. The higher the antenna gain, the more

precise the alignment should be.

Directional antennas are typically used to connect:

• A Base Station and a Subscriber Station in a point-to-point link

• A Subscriber Station in a point-to-multipoint network

See the following sections:

• Omni-Directional Antennas

• Flat Panel Directional Antennas

• Sector Antennas

• Parabolic Dish Antennas

Omni-Directional Antennas

Omni antennas radiate the signal 360 degrees horizontally; however, they increase gain by flattening the radiated signal

pattern, producing a vertical beam between 80 degrees (modest gain) and 7 degrees (high gain). Gain makes the signal

travel further.

These antennas have an omni-directional azimuth pattern that makes them easy to install. There is also a

gain-to-beamwidth relation for omni-directional antennas: the higher the gain of the omni-antenna, the narrower the

vertical beamwidth. In a hilly terrain, an 8 dBi omni-directional antenna can be a better solution than the 10 dBi

omni-directional antenna, because the lower gain antenna has a larger vertical beamwidth. The larger vertical beamwidth

allows signal coverage to a greater elevation, which in turn allows coverage higher up hillsides. This effect could be

useful when the antenna is located at a low elevation such as a valley floor.

Figure 1-1 Omni-Directional Antenna Coverage