IDENTIFICATION
ID ISC.LRU3000 / LRU3500
5 Operating and Display
Elements
Page 23 of 30
5.3 Reader Power adjustment
To achieve the optimum reading performance it is necessary to set the reader output power to the highest
allowed value. This depends on the used reader type (EU / FCC) and the regulation in the country were the
reader is used.
5.3.1 EU-Reader according to EN302 208
According to the standard EN302 208 the maximum radiated power is 2 W e.r.p. (Effective Radiated Power)
in countries of the European Union. The in the reader configured output power P
out
depends on the antenna
gain in dBi and the attenuation of the antenna cable. If a circular polarized antenna is used the antenna gain
[dBic] can be reduced by 3dB. At a linear polarized antenna the maximum linear antenna gain [dBi] must be
used.
P
Out
= P
erp
- Antenna Gain + Cable loss + 2,1dB**
** Correction Factor to convert the radiated power from e.r.p to e.i.r.p.
For the calculation of the reader output power P
Out
an
Excel file „Calc-RF-Power.xls“ can be used. Available
from Feig Electronic GmbH.
Example:
** linear antenna = „0“, circular antenna = „1“
Fig. 20: Calculation of the output power
In Figure 20 he allowed antenna power is shown for the use of the FEIG standard antenna ANT.U600/270
–
EU and a 6m long Belden H155 coaxial cable.
According to the FCC approval, Title 47, Part15 the maximum output power of the reader is limited to 1 W
(30dBm). The maximum radiated power of the antenna should not increase more then 4 W e.i.r.p. Due to these
facts two different cases have to be considered:
