Product Guide

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Cascade 2019 Product Guide
CASC-2019-01
RF Maximum Permissible Exposure (MPE)
Exhibit Requirements for Installations in Canada
MPE and Safe Distance Calculations for Canada Installations
For Canada installations, the maximum power density resulting from the composite Effective Isotropic Radiated Power (EIRP) from the antenna connected to this
equipment must be limited to the maximum permissible exposure as stated below:
• Power density limit for the band 152 to 174MHz = 1.291 W/m²
The MPE calculation for US is expressed as follows:
• Power Density Pd (W/m²) =
Where
• d = distance from the antenna expressed in meters (m)
• EIRP expressed in Watts (W) =
• Tx Power (dBW) = 10*log[Tx Power (W)]
As an example, with the transmitter running at 100 watts output into an antenna with a gain of 10 dBi using a short cable with 0dB loss, to verify if 7.5meters is a safe
distance from the antenna to ensure exposure compliance of 1.21W/m2:
4) 100 Watts Tx Power = 20dB
5) EIRP (W) =
6) Pd (W/m2) =
• 8.5 meters is a safe distance for Canada installations when using a 10dBi gain antenna.
When installing the antenna, the above relationship should be used to ensure the combination of power, antenna gain, and distance is such that the maximum
permissible power density is not exceeded. Different combinations of output power and antenna gain will result in different minimum safe distances.
The minimum safe distance, from a radiating structure using different Gain Antennas”
• For the Band 152 to 174MHz with 2dBi Gain Antenna: d (safe distance) = 3.5 m
• For the Band 152 to 174MHz with 6dBi Gain Antenna: d (safe distance) = 5.5 m
• For the Band 152 to 174MHz with 10dBi Gain Antenna: d (safe distance) = 8.5 m