•
Antennas must be kept a suitable distance from each other. Check the receive signal strength on the
Connectivity page of the module and ensure that the level is not greater than
–45 dB. For more information,
see
“5.2 Connectivity” on page 70.
Antennas
Antennas can be either connected directly to the module connectors or connected via 50-ohm coaxial cable (such
as RG58 Cellfoil or RG213) terminated with a male SMA coaxial connector. The higher the antenna is mounted, the
greater the transmission range, but as the length of coaxial cable increases so do cable losses.
The net gain of an antenna and cable configuration is the gain of the antenna (in dBi) less the loss in the coaxial
cable (in dB). Maximum net gain for the WI-MOD-xxx-E-5W will depend on the licensing regulation for the country
of operation and the operating frequency.
Typical antennas gains and losses are:
Antenna
Gain (dBi)
Dipole
2 dBi
Collinear
5 or 8 dBi
Directional (Yagi)
6
–15 dBi
Cable Type
Loss (dB per 30m/100 ft)
RG58 Cellfoil Cable kits (3m,10m, 20m)
–1dB, –2.5dB, –4.8 dB
RG213 per 10m (33 ft)
–1.8 dB
LDF4-50 per 10m (33 ft)
–0.5 dB
The net gain of the antenna and cable configuration is determined by adding the antenna gain and the cable loss.
For example, an 8 dBi antenna with 10 meters of Cellfoil (
–2.5 dB) has a net gain of 5.5 dB (8 dB – 2.5 dB).
Dipole and Collinear antennas
Dipole and collinear antennas transmit the same amount of radio power in all directions, and are easy to install and
use because they do not need to be aligned to the destination. The dipole antenna does not require any additional
coaxial cable. However, a cable must be added if using any of the other collinear or directional antennas. In order to
obtain the maximum range, collinear and dipole antennas should be mounted vertically, preferably one wavelength
away (see Figure 9 for distances) from a wall or mast and at least 3 ft (1m) from the radio module.
Figure 9 Collinear/Dipole
