R3765/67G Series Network Analyzer Operation Manual
7.10 Software Fixture Function (OPT 71/72)
7-105
•
When measuring a 4-port device (OPT 14 is required)
Degree of balance between TEST PORT 3 and TEST PORT 4: B34 = -(S31-S32)/(S41-S42)
Degree of balance between TEST PORT 4 and TEST PORT 3: B43 = -(S41-S42)/(S31-S32)
Degree of balance between TEST PORT 1 and TEST PORT 2: B12 = -(S13-S14)/(S23-S24)
Degree of balance between TEST PORT 2 and TEST PORT 1: B21 = -(S23-S24)/(S13-S14)
7.10.2.6 Software Balun Function (OPT 71 only)]
The software balun function connects an ideal balun between the measurement ports to convert
a balanced device into a 2-port unbalanced device and measures the characteristics of the con-
verted 2-port unbalanced device.
The ideal balun can be selected from two types, a floating balun and a differential balun.
Note:
The software balun function is not available for OPT 72.
Floating balun
Differential balun
•
When measuring a 3-port device (OPT 11 or 14 is required)
An ideal balun is connected between TEST PORT 2 and TEST PORT 3 and these ports are
converted into the balanced port TEST PORT2’.
The DUT is measured as a 2-port network of TEST PORT1 to TEST PORT 2’ and S-
parameters are displayed as SS11, SS21, SS12 and SS22.
1
This is an ideal transformer of floating type isolated from
GND.
This type of balun is used to evaluate the floating device
unaffected by the common impedance between the
measurement port and GND.
2
This is an ideal transformer of differential type with the
neutral point grounded.
This type of balun is used to evaluate the device whose
measurement port is balanced to GND.
