Agilent Technologies PSA Series User And Programming Manual page 180

Instrument Functions: M - O
Marker Fctn
To measure the ratio of the noise densities at two locations, be sure that the
. (The noise is averaged over a region that is 5% of the span, centered at the
Marker Noise
marker location.) Select
( ∆ ) marker to the second noise location. In this case both markers have units of noise
density (for example, dBm/Hz), so the data displayed represents the ratio of the noise
density at the delta marker to the noise density at the reference marker. The value readout
is displayed as a ratio (dB or %).
To guarantee accurate data for noise-like signals, a correction for equivalent noise
bandwidth is made by the analyzer. The
detector is set to
Average
noise. The trade off between sweep time and variance of the result is best when
is set to Power Averaging.
Type
detector and
Power Averaging
detector and
Avg/VBW Type
accurate measurement results.
Key Path:
Marker Fctn
Dependencies/
Couplings: triggering is not available when the detector is
Video
marker functions that would set the detector to
with video triggering, are not available when the
Remote Command:
See "Marker Fctn" on page 179
Remote Command Notes: Note that the value when the Y-axis units are watts is the
square of the value when the Y-axis units are volts. For example, when the
percent ratio with Y-axis units in volts is 20% (0.2), the percent ratio with
Y-axis units in watts will be 4% (0.2
remotely you have to know whether you are in log (dB) or linear (percent),
and if linear, whether volts or watts.
Example: CALC:MARK:FUNC NOIS turns on marker 1 as a noise marker.
CALC:MARK:FUNC? returns the current setting of marker function for the
marker specified. In this case it returns the string: NOIS.
CALC:MARK:Y? returns the y-axis value of the
marker 1 (if
180
, before selecting
Marker Normal
Marker Noise
or , because neither of these detectors will peak-bias the
Sample
coupling, therefore, normally chooses the
Auto
. Though the Marker Noise function works with all settings of
, using the positive or negative peak detectors gives less
for the command to select a function.
is ON for marker 1).
Marker Noise
marker. Then move the active
Delta
function accuracy is best when the
Average
, and thus conflict
Average
trigger is
Video
2
= 0.04). When you read the value out
Marker Noise
is
Marker Fctn
Avg/VBW
Average
, therefore
.
On
function for
Chapter 3