Measurement
Assembly
TK5530
All parameters are measured in a Helmholtz-arrangement, which generates a homoge-
nous magnetic field (see Figure 5 and Figure 6). A function generator drives the field
generating coils, so the magnetic field can be varied in frequency and field strength.
Figure 5. Testing Application
SENSING COILS ( IN PHASE )
TK5530
REFERENCE COIL
( IN PHASE )
SUBTRACTOR
AMPLIFIER
1:10
REFERENCE COIL ( IN PHASE )
OUTPUT
VOLTAGE
FIELD GENERATING
COILS ( IN PHASE )
FUNCTION
GENERATOR
Figure 6. Testing Geometry
l = 30 mm
22 mm
Transponder
d = 60 mm
REFERENCE COIL
SENSING COIL
5 mm
FIELD GENERATING COIL
SENSING COIL
REFERENCE COIL
FIELD GENERATING COIL
5
4683A–RFID–02/03