User Manual

SARK-110-ULM User’s Manual
Rev 1.0 June 22
th
, 2019 - 45 - © 2019, Melchor Varela – EA4FRB
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
FraLa
Ca

=

The series equivalent resistance of the antenna at the operating frequency Fop = 13.56 MHz is
calculated with the following equation:
Rp
LaFop
RsRa
2
)2( 
+=

The quality factor is calculated using the following equation:
Ra
LaFop
Qa

=
 2
4.2.2 Capacitor
This function determines the equivalent circuit model of capacitors. The measurement
procedure is as follows: