HP 8712C, User Manual, Page: 242 / 559

I
Optimizing Measurements
Compensating for Phase Shift in Measurement Setups
lb use the port extension feature, press [CAL) Cal,
OFF . When port extension is turned on, you can add delay
independently to both the reflection port and the transmission port.
‘lb add delay between the REFLECTION RF OUT port and your DUT, press
1
, and enter the delay value.
lb add delay between the TRANSMISSION RF IN port and your DUT, press
, and enter the delay value.
The delay values that you enter will be automatically applied appropriately to
both transmission and reflection measurements. When measuring reflection,
the reflection port extension delay is applied twice. When measuring
transmission, the reflection port extension delay and the transmission port
extension delay are each applied once.
Another type of reference plane extension is ,
accessible from the key. Electrical delay lets you add delay to
your current measurement to compensate for phase shift. lb flatten the
phase response at a certain frequency, use (MARKER)
. This automatically adjusts the electrical delay to
compensate for the phase slope at the active marker position.
Unlike port extension, electrical delay does not automatically adjust the
applied delay when you switch between transmission and reflection
measurements. For this reason, port extensions are preferred over electrical
delay.
N O T E
Reference plane extension only affects narrowband measurements.
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