B&B Electronics Wireless Antenna Installation Manual - Required Antenna Gain
Wireless Antenna Installation Guide |
7
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 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:
Radio Frequency
& Wattage
300 ft
(100 m)
1000 ft
(300 m)
1 mile
(1.6 km)
5 miles
(8 km)
10 miles
(16 km)
2.4 GHz, 60mW
2.1 dB
>6 dB
>10 dB
—
—
900 MHz, 1W
2.1 dB
2.1 dB
>3 dB
>6 dB
>10 dB
Note: RF signal is lost across cables and connections. Refer to Tip 4 to know the impact of
cable lengths and connections and how to select the antenna gain to compensate for the
signal loss.
SIGNAL LOSS ACROSS COMPONENTS
Signal Loss
868/900 MHz
2.4 GHz
Antenna Cable (LMR400)
-3.9 dB/100 ft
-6.8 dB/100 ft
Connectors (RP-SMA/N-Type)
-0.5 dB
-0.5 dB
Lightning Arrestors
-1 dB
-1 dB