ADC Telecommunications Inc. F0694-011 Benutzerhandbuch

B-4

CONFIDENTIAL

The basic equation for determining power density is:

πR

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.

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 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.

Using S = PG/4

π

R

2

S = 224/(4x3.14) x (122)

2

 = 0.001 mW/cm

2

Also, assuming a minimum distance of 20 cm according to FCC regulations”

S = 224/(4 x 3.14) x (20)

2

 = 0.04 mW/cm

2