Keysight Technologies 8163A, Руководство пользователя

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104 8163A/B, 8164A/B, 8166A/B User’s Guide
3 Power Measurement
How to Set the Reference Value to the Current Power Value
In addition to entering a new reference value, you can change the
reference value to the currently displayed power value by pressing the
[Dsp->Ref] softkey.
Pressing the [Dsp->Ref] softkey takes the input power level and stores it as
the reference. Setting the reference only affects results displayed in dB.
When you press the [Dsp->Ref] softkey, the absolute power level, the
power value in dBm or Watts, is stored as the reference, that is:
REF = P
measured
Where,
REF is the reference, and
P
measured
is the absolute power level (see How to Set the Calibration Offset
on page 102).
The [Dsp->Ref] softkey is displayed if you move to a power measurement
channel.
How to Reference Another Power Measurement Channel
You can use the reference mode, [ Ref Mode ], to reference another Power
Meter’s current power level. If you choose this mode, the reference of the
channel continuously updates to the current power value measured by the
other channel.
The following equations describe how the power in dB is calculated if you
reference another channel:
P
display
(dB) = P
measuredA
(dBm)
-
P
measuredB
(dBm)
-
REF(dB)
or
Where:
P
display
is the displayed relative power,
P
measuredA
is the absolute power level (see How to Set the Calibration
Offset on page 102) measured by the current Power Meter, and