RFID-UHF-Antennas
12
6 Compliance with standards
As RFID systems are radio installations, they fall under the European Commission
directive 1999/5/EC (Radio Equipment and Telecommunications Terminal Equip-
ment R&TTE)�
A series of harmonised standards are in place to prove conformity with the basic
requirements of this directive, which are published in the official journal of the
European Union�
The ifm antenna ANT820 is a passive antenna structure� It is therefore the system
integrator who is responsible for ensuring compliance with the standards – i�e� the
person who combines the individual components of an RFID system with each
other, in particular the reader and antennas� We therefore strongly recommend
acquiring these standards�
Two important standards in relation to antennas are (with no claim of complete-
ness) EN 302208 and EN 50364: The first deals with frequency spectrum issues
and limits the maximum radiated power, while the EN 50364 addresses the limits
regarding exposure of people to electromagnetic fields�
In accordance with EN 50364, compliance is achieved if the defined limit values
of the electrical and magnetic field strength are not exceeded at a distance of 20
cm around the antennas� On compliance with the maximum antenna input power
specified in the standard EN 302208, the electrical and magnetic field strength
from the antenna ANT820 are below the defined limits at a distance of 20 cm�
Compliance with the standards is therefore ensured�
As the antenna ANT820 can be used for special applications also with a read
range of less than 20 cm, numerical calculations have also been made on the
specific absorption rate (SAR)� The calculated SAR values are compared with the
basic limit values of EN 50364 – separated according to professional exposure
and exposure to the general public, as well as local exposure to head and body or
the extremities� The assumptions made here (such as the operating mode of the
RFID system and properties of the human skin) guarantee a conservative estima-
tion of the exposure (worst case scenario)�
The calculation was also carried out for the most sensitive constellation, i�e� for the
event that members of the general public are permanently located in close proxim-
ity to the antenna with head and body� If the distance between the person and the
antenna is less than 3 cm, with the ANT820 it is ensured the rate remains below
the maximum SAR allowed with an antenna input power of up to 0�34 W (25�31
dBm)� In all other cases the ANT820 can be operated using the maximum radiated
power specified in the data sheet of 0�5 W ERP (27 W ERP) or an antenna input
power of 0�653 W (28�15 dBm)�
