ADC InterReach Fusion Installation, Operation And Reference Manual page 218

B-4
CONFIDENTIAL
ADC products transmit well below the FCC power density limits. FCC defines power
output limits at 20cm distance for various frequency ranges:
• Over 300 mHz to 1.5 GHz the limit is determined by frequency/1500
• Above 1.5 GHz the limit is 1mW/cm2
The basic equation for determining power density is:
2
S = PG / 4SR
Where S is power density in mW/cm2
PG, the transmitted power from the antenna identified as EIRP (Equivalent Isotropi-
cally Radiated Power), is the product of power output of device and antenna gain, in
mW.
R is the distance of interest from the antenna.
Typical Installation Example:
Assuming an antenna is placed on a 10 foot ceiling, for a person 6 feet tall, the dis-
tance from antenna to body is 4 feet (112 cm.).
For a PCS 1900 or Cell 850 remote unit, the maximum power output, according to the
power table in Section 6.3 Maximum Output Power per Carrier on page 6-4, is 16.5
dB.
Assuming a 7 dBi antenna is used, PG in the equation is equal to 23.5 dB (224 mW)
EIRP.
S
Using S = PG/4 R
S = 224/(4x3.14) x (122)
Also, assuming a minimum distance of 20 cm according to FCC regulations"
S = 224/(4 x 3.14) x (20)
InterReach Fusion Installation, Operation, and Reference Manual
2
2 2
= 0.001 mW/cm
2 2
= 0.04 mW/cm
D-620610-0-20 Rev D