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3.9

Antenna Calculation

L

RL

CLpar

Cchip

Rcont

Rchip

Rcont

CHIP

Resonance frequency:

=

1

fres

2* Π*L*Cchip

Total Quality factor:

Qc*Ql

Qres=

Qc+Ql

Input Impedance:

L

Z=Qres*

Cchip

Antenna Calculation

Rchip: IC input impedance

Cchip: IC input capacitance

Rcont: Pad/assembly contact resistance

CLpar: Parasitic capacitance of antenna

RL: Series resistance of antenna

L: Antenna Inductance

Based on an IC capacitance of 23.5 pF, the impedance shall be matched to be in the specified impedance

range of 6.5 to 15.5 k

Ω to fit the IC capabilities.

Note:

If Z>15.5 k

Ω, reduced performance of read range must be considered.

26

Shipping, Packing and Further Handling

SCBU047 (11-09-21-064) – October 2007

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