Impedance Parameters - Keysight E4980A User Manual

Measurement Procedure and Examples

Impedance Parameters

Impedance Parameters
All circuit components, resistors, capacitors, and inductors have parasitic
components lurking in the shadows waiting for the unwary. These include, for
example, unwanted resistance in capacitors, unwanted capacitance in
inductors, and unwanted inductance in resistors. Thus, simple components
should be modeled as complex impedances.
Figure
vector representation of impedance. Impedance, Z is the total opposition that a
circuit or device offers to the flow of alternating current at a given frequency. Z
contains a real and an imaginary part, and it is expressed in rectangular form
as Resistance and Reactance, or in polar form as absolute value of Impedance
and Phase as follows.
Z
Z

R
Where,
Z
R
X
|Z|

Rs
Keysight E4980A/AL Precision LCR Meter
7-2(A) shows the impedance definitions, and
R jX Z
 
= + =
2 2
R X
= +
X
 
atan
----- -
=
 
R
Rs
=
Impedance []
Resistance []
Reactance []
Absolute Value of Impedance []
Phase of Impedance [deg or rad]
Series Resistance []
Figure 7-2 (B) shows the
187