SARK-110
User’s Manual
Rev 1.2.19 January 12
th
, 2020
- 73 -
© Melchor Varela
– EA4FRB 2011-2020
Fra
Self-resonant frequency of the antenna
Z(Fop) Z at operating frequency
Z(Fra)
Z at resonant frequency
Rs
Equivalent resistance at F = 1 MHz
La
Equivalent inductance at F = 1 MHz
Rp
Equivalent resistance at the self-resonant frequency
The antenna capacitance is calculated with the following equation:
2
)
2
(
1
Fra
La
Ca
=
The series equivalent resistance of the antenna at the operating frequency Fop = 13.56 MHz is
calculated with the following equation:
Rp
La
Fop
Rs
Ra
2
)
2
(
+
=
The quality factor is calculated using the following equation:
Ra
La
Fop
Qa
=
2
4.2.2 Capacitor
This function determines the equivalent circuit model of capacitors. The measurement
procedure is as follows: