IFM Electronic ANT805, Operating Instructions Manual

UK

RFID UHF antennas

9

4  Reading range and selectivity

The reading range and the selectivity are the most important features of an RFID 

application� The reading range describes the greatest distance at which a tag 

can be read� The selectivity indicates the required minimum distance for clear 

distinction between two adjacent tags�
The system features depend considerably on the tag type used� In general, the 

UHF RFID tags can be divided into three groups�

Figure: Loop-shaped tag

The first group consists of loop-shaped tags that 

couple magnetically with the antenna� These tags 

have the smallest ranges since the magnetic field 

decreases rapidly with the distance from the antenna�
The second group consists of hybrid-type tags which 

are a mix of loop-shaped and dipole-type tags� These 

tags can be activated by the antenna via the 

magnetic field, the electric field or a combination of 

both� 
The third group is made up of dipole-type tags (far 

field tags) which mostly couple via the electric field� 

Ranges of more than 10 m are possible�

4.1  Antenna allocation according to tag types

The ANT805 ultra-low-range antenna was developed to meet the most challenging 

demands with regard to range and selectivity of the tags from all three groups� It is 

a universal antenna for many low-range applications� With this antenna very low 

reading ranges below 10 cm and high selectivity with far-field tags are possible� It 

can also read near-field tags at distances of up to 3 cm� 
In order to significantly increase the read distance for near-field tags, the ANT810/

ANT910 low-range antenna was developed for reading ranges of 7 cm with 

conventional loop-shaped tags�
The ANT805 ultra-low-range antenna is suited for all groups while the ANT810/

ANT910 low-range antenna is particularly suited for use with loop-shaped tags�

4.2  Reading range

In order to quantify the reading range of the ANT805 and ANT810/ANT910 

antennas the figures below show the respective reading ranges for different tag 

designs� The tags are aligned parallel to the antenna�
The ANT805 antenna has a very well-defined reading range for all tags� The 

ANT810/ANT910 antennas are special solutions for near-field tags with a 

considerably larger reading range than the ANT805 antennna�

Figure: Hybrid-type tag

Figure: Dipole-type tag