2.2.2 Antenna
Connection
This equipment has been tested and approved with antennae having a maximum gain of 8.5 dB. Antenna
with a higher gain are strictly prohibited (regulations of Industry Canada). The required antenna imped-
ance is 50 ohms. To reduce potential radio interference, the antenna type and its gain should be chosen to
ensure the effective isotropic radiated power (EIRP) is not more than required for successful communica-
tion.
FCC/IC Rule: The output power is not to exceed 1.0 watt (30 dBm) and the EIRP not to exceed 6 dBi
gain (36dBm). A sample calculation is provided below.
Referring to Figure 2:
Sample Calculation:
Yagi Antenna: 8.5 dBi, which exceeds 6 dBi gain by 2.5 dB
Cable Loss: 1.5 dB
HiPR-900 output initially set to 30 dBm (1 watt).
(Initial output level) dBm - (excess antenna gain) dB + (cable loss) dB = (new power setting) dBm
Therefore, the sample calculation becomes: 30dBm – 2.5 dB + 1.5dB = 29 dBm
The HiPR-900 output must be reduced by 1 dB to 29 dBm.
29 dBm
“T” = TX/RX
“R” = RX
27.5
8.5
Figure 2 - Sample equation
2.2.3 Spacing and Constraints
Referring to Figure 3, HiPR-900 radiomodems commonly use two separate antennae:
•
“T” - Main transceiver -
Constraints are the limit of 9.06 in/23 cm (see 2.2.1 above) and omni-directional factors
•
“R” - Auxiliary receiver –
Constraints are the receiver spacing of at least 5/8
λ
(wavelength) from transceiver antenna and omni-
directional requirements
(8in. / 21cm)
For the optimum antenna spacing at the frequency you are using, consult Dataradio System Engineering.
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HiPR900 User Manual
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