SeeedStudio SARK-110, User Manual, Page: 84 / 103

SARK-110 User’s Manual
Rev 1.2.19 January 12
th
, 2020 - 84 - © Melchor Varela
– EA4FRB 2011-2020
Appendix B: Fundamental Parameters
Abbreviation Parameter Description
Rs Series resistance Resistive value of a series impedance
Xs Series reactance Reactance value of a series impedance
Rp Parallel resistance Resistive value of a parallel impedance
Xp Parallel reactance Reactance value of a parallel impedance
|Zs| Magnitude of a
series Impedance
Represents the absolute magnitude of the ratio of the
voltage difference amplitude to the current amplitude.
( )
2 2
| | X R Z
+ =
<Zs Impedance Angle It is a measure of the phase angle of the ratio of the
amplitude of the voltage to the amplitude of the current,
expressed in degrees.
VSWR Voltage Standing
Wave Ratio
It is a measure of how efficiently radio-frequency power is
transmitted from a power source, through a transmission
line and into a load (for example, from a power amplifier
through a transmission line and into an antenna).
RL Return Losses
(S11 dB)
Return loss is the negative of the magnitude of the
reflection coefficient in dB.
) ( 10 log 20 Rho RL
 =
CL Cable Losses Measurement of insertion loss of a cable in dB. The
measurement should be performed by applying a short
circuit at the cable end.
)
2
(
RL
ABS CL
=
|Rho| Magnitude of a
Reflection
Coefficient (Rho or
S11)
It is a measure of the absolute magnitude of the ratio of
the amplitude of the reflected wave to the amplitude of the
incident wave.