OBID i-scan
®
Montage / Installation
ID ISC.MAT-B
FEIG ELECTRONIC GmbH
Page 15 of 19
M70101-0e-ID-B.doc
The objective of the tuning process is to tune the antenna as close as possible to 50
Ω
.
Maintain the following tolerances:
R = 50 +/- 3
Ω
and X = 0
+/- 5
Ω
(or Z = 50 +- 3
Ω
and phase angle Phi = 0° +/- 3°)
Fig. 12: The resistance (R) and inductance (X) of the antenna as a function of frequency
Procedure for tuning an antenna in individual steps:
1. Connect tuner board (with antenna attached) to impedance analyzer.
2. At C
1/1
and C
1/2
enable the same capacitance of 15pF or 30pF.
3. Change capacitance C
2
to the value closest to R=50
Ω
using the jumper strip J3
4. Change capacitances C
1,1
and C
1,2
to the value closest to X=0
Ω
and
γ
= 0° +/- 3° on J3
5. Use capacitance C
2
(on J3) to recalibrate to the value closest to R=50
Ω
and Z = 50
Ω
.
6. If necessary repeat steps 5 and 6 until the working point 50
Ω
lies within the specified tolerance
(+-3
Ω
) and no more improvement is possible.
R=50
Ω
X =0
Ω
