User Manual

Library Security Pedestal 2
46/62 Revision 4.2 July 2008
For the best impedance, adjust the trimmer capacitors (Figure 27) until the two curves on the
oscilloscope are exactly superimposed. For optimal performances, the two trimmer capacitors
should be set to approximately the same angle. Please see Figure 28 .
Figure 27: Trimmer Capacitor
Figure 28: Adjusting Trimmer Capacitors
The individual impedance for each antenna should be tuned to be as close as possible to:
Z0 = 50±5 + 0j±5 Ω at 13.560 MHz
Figure 29: Impedance Values using the Tuning Kit
Poor Impedance
Good Impedance
Continue the tuning process by checking the antenna isolation (see section 6.4 “Adjusting the
antenna Isolation
”).
Trimmer capacitor