Wireless Antenna Installation Guide:
10 Tips for Making Your Wireless Installation a Success

How to Choose the Right Antenna

Yagi Antenna

A directional antenna. Focuses energy to one particular direction. In a point-to-point application, it is ideal to use Yagi antennas at both locations for extended range and better signal strength. Yagi antennas generate best results in point-to-multipoint applications when used with remote slave radios.

Omni Antenna

Omni-directional antennas focus their energy equally in all directions. They typically have lesser range than a Yagi antenna of similar gain. Omni antennas are used in point-to-multipoint applications for the central master unit.

Point-to-Point
In this configuration, two radios will be talking to one another. Typical examples are serial-to-serial communication or peer-to-peer I/O wire replacement systems. Yagi antennas at both ends increase signal strength, range and reduce interference.

Point-to-Multipoint
In a multipoint system, an Omni antenna is typically used as the master with individual Yagi antennas as “slaves” pointing to the “master” antenna for the best range and signal strength. A typical example is Modbus I/O configuration with a Radio Modem connected to an RTU master with several I/O nodes as slaves.

Wireless Antenna Installation Tips

RF Range is influenced by several factors. Proper consideration during installation will help enhance the signal strength and range ensuring reliable operation.

Tip 1 - Clear RF Path of Obstructions

Make sure the RF path is clear of obstructions. Antennas should be installed where they can “see” each other as much as possible. Make sure the antennas are high enough above any obstructions in the RF path.

Tip 2 - Pay Attention to Antenna Alignment

Make sure the antennas are aligned to center of the signal path and angle, and on the same level plane.

Tip 3 - Know Your Overall System Gain Required to Meet the Distance

The more the distance between the radios, the more the overall system gain needs to be. A quick rule of thumb for the overall system gains vs. distance is as below:

Tip 4 - Know Your Signal Losses and the Required Antenna Gain

Signal is lost across cables and connectors. The longer the antenna cable and the more the number of connections, the more the signal loss. A larger antenna gain is necessary to compensate for these losses and to meet the required distance. As a rule of thumb, the RF range will be reduced by half for every 6 dB signal loss.

The lost signal has to be compensated by choosing a proper antenna gain. B&B’s 900 MHz Zlinx and Zlinx Xtreme radios come standard with a 3 dBi Omni antenna and the 2.4 GHz radios come with a 2.1 dBi gain Omni antenna. If more gain is necessary, choose a higher gain antenna depending on your system requirement.

The table below shows the signal loss across cables and connections.

Tip 5 - Use the Minimum Cable Length Required

Use the minimum cable length required. Do not run more cable than needed.

Tip 6 - Do Not Wrap the Cables

Do not wrap or coil the cables around anything.

Tip 7 - Use Drip Loops

Use drip loops at the cabinet. This keeps moisture from collecting between the connection joints and in the cabinet itself. When using cabinets, bottom cable entry is recommended versus side entry. Never run the cable in through the top of your cabinet.

Tip 8 - Protect the Antenna Connection

Protect the antenna connection with the correct vulcanizing rubberized tape.

Tip 9 - Correctly Phase the Yagi with Respect to the Omni Base Antenna

Make sure Yagis are phased (oriented) correctly with respect to the Omni base antenna.

Tip 10 - Correctly Phase Yagis with Respect to Each Other

Make sure Yagis are phased (oriented) correctly with respect to each other.

Additional Resources

The table below shows the maximum distance for different antenna and cable combinations at different terrains. Impact of weather is not factored in.

Online Resources

For more information, visit B&B Electronics Technical Library, Wireless section.

• 10 Commandments of Wireless Communication
• Wireless Range Estimator
• Making Wireless Work: Antenna and Cable Selection

B&B Electronics Technical Support Team

Before, during and after the sale, we are here to make it easy. With more than 30 years of industrial communications experience, we will help you through your toughest problems. And it is always free.

Call 815-433-5100, 8am-5pm central time or email support@bb-elec.com.

EMEA customers call +353.91.792444 or email support@bb-europe.com. In the UK call +44.01926.851500.

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