How To Reference Another Power Measurement Channel - Agilent Technologies 8163A User Manual

How to Measure Power
Agilent 8163A/B, 8164A/B, and 8166A/B User's Guide, Fourth Edition
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 is the absolute power level (see "How to Set the
measured
Calibration Offset" on page 81).
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 (dB) = P
display
or
Where:
P is the displayed relative power,
display
P is the absolute power level (see "How to Set the
measuredA
Calibration Offset" on page 81) measured by the current
Power Meter, and
P is the absolute power level (see "How to Set the
measuredB
Calibration Offset" on page 81) measured by the Power
Meter you choose to reference, and
REF is the reference level in decibels (dB).
N O T E
You can only set the reference level, REF, in decibels (dB) when you
reference Power Meter's current power level. This reference level is
stored in separate memory than the absolute reference level.
To reference another channel:
1 Move to the Power Meter channel and press the [Details] softkey.
2 Move to the [Ref Mode] parameter and press Enter.
(dBm) − P
measuredA measuredB
P
measuredA
( )
P dB = 10 log -------------------------------------
displ ay
P
measuredB
Power Measurement
(dBm) − REF(dB)
( )
W
( )
– REF dB
( )
W
83