Balluff BIS U Basishandbuch Seite 49

BIS U Basic Manual
7
Component Properties and System Characteristics
7.4 Directional The data carrier is sensitive to orientation because of the dipole antenna principle.
Characteristics of
the Data Carrier
Dipole Antenna
Figure 10:
The following qualitative statements apply:
–
–
–
7.5 Responsiveness In order to supply power to the ICs, passive RFID data carriers are instructed to draw the
of the Data
required energy from electromagnetic waves radiated by the antenna on the processor unit.
Carrier -
Response Field The response field intensity is the minimum field intensity required to operate the integrated
Intensities circuit that is present at the location of a data carrier. The use of the external electric field, which
generates a sufficiently high RF voltage at the antenna connections, is largely influenced by the
antenna design and capacity to adjust to the operating frequency.
The power consumption of the data carrier ICs varies for each individual semiconductor
manufacturer and design generation, and has an influence on the responsiveness of the data
carrier.
Responsiveness is a particularly important aspect because the processor unit can usually detect
a data carrier located in a RF field of sufficient intensity.
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Antenna
x
α
z
Directional sensitivity of the data carrier dipole antenna
If a circular polarized transmitting antenna is used, no directional sensitivity is observed when
the antenna is rotated around the z-axis.
When the antenna is rotated around the x-axis, a reduction in sensitivity is observed at
rotation angles of 90° and 270°.
When the antenna is rotated around the y-axis, read capability is absent at rotation angles of
90° and 270°.
330
300
270
v
240
φ
210
180
0° position represents the
flat position on the x-y
plane.
0
30
60
90
120
150
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