50
N9912A FieldFox User’s Guide
Port Extensions
Port extensions allow you to electrically move the calibration reference plane on
port 1 after you have performed a calibration.
Phase measurements, and therefore Port Extensions, are NOT available on port
2.
Why use Port Extensions
Use port extensions if you are unable to perform a calibration directly at your
device because the location is not accessible. Perform a calibration at a
convenient place, then use port extensions to compensate for the time delay
(phase shift) to the desired reference plane. On the FieldFox, port extensions
does not compensate for the loss of the additional electrical length, nor any
mismatch errors beyond the calibration reference plane.
Also use port extensions if you have already performed a calibration, and then
decide that you need to add a length of transmission line in the measurement
configuration. Use port extensions to "tell" the FieldFox that you have added the
length to a specific port.
With S11, the FieldFox doubles the port extension valued that you enter to
account for the additional delay in the forward and reverse directions.
Port extensions and Electrical Delay differ in the following ways:
Electrical delay is applied to a specific trace.
Port extensions are applied to specific ports.
Port Extensions and Electrical Delay can be set independently. When both are
set, the delay adds together. Learn more about Electrical Delay on page 45.
How to apply Port Extensions
Press
Meas Setup 4
.
Then
Port Extensions
Then
Port Extensions ON
Then
Port1 Extension
Then enter time value using the numeric keypad, the
▲|▼
arrows, or the
rotary knob. Press
Enter
or select a seconds (time) multiplier.
You can also set Port Extensions by pressing
Meas Setup 4
then
Calibration
(settings).
While setting Port Extension, the physical length of the extension, at the current
Velocity Factor setting, is visible to the right (red box in above image).
Velocity Factor
The electrical delay or port extension value is entered as delay, or
electrical
length,
in units of time.
Summary of Contents for FieldFox N9912A
Page 15: ...Preparing for Initial Use of Your New FieldFox 15 Take the FieldFox Tour Front Panel ...
Page 194: ...194 N9912A FieldFox User s Guide Batteries Safe Handling and Disposal ...
Page 195: ...Safety Considerations 195 Inspired Energy Battery ...
Page 196: ...196 N9912A FieldFox User s Guide ...
Page 197: ...Safety Considerations 197 ...
Page 198: ...198 N9912A FieldFox User s Guide ...
