R3765/67G Series Network Analyzer Operation Manual
7.10 Software Fixture Function (OPT 71/72)
7-100
Impedance after conversion
Figure 7-13 Dynamic Range When Changing the Impedance
•
S-parameter and characteristic impedance
The impedance conversion function allows you to set the characteristic impedance used to
describe the S-parameter to an arbitrary value.
Where the voltage is V
i
, the current is I
i
and the impedance is Z
i
for the port i, the incident
wave a
i
and the reflected wave b
i
are obtained using the following expressions.
The S-parameter S
ij
for an n-port device is defined by the following expression using the
incident wave a
i
and reflected wave b
i
.
•
Calculating each parameter individually
As shown above, the S-parameter is defined as an element of a matrix. However, each
parameter can be obtained using a simple circuit calculation.
As an example of a 2-port device, the calculation method where the PORT 1 impedance is
Z
1
and PORT 2 impedance is Z
2
is given below.
(
Ω
)
(dB)
Dynamic range attenuation
