Technical data

Frequency / Channel 8
Agilent N8201A Performance Downconverter Synthetic Instrument Module, 250 kHz to 26.5 GHz 181
Signal Track
When a marker is placed on a signal and Signal Track is pressed, the marker will remain on
the signal while the N8201A retunes the center frequency to the marker frequency. The
N8201A will keep the signal at the center of the display, as long as the amplitude of the
signal does not change by more than 3 dB from one sweep to another. If no marker is active,
pressing Signal Track to On will activate a marker, perform a peak search, and center the
marker on the display.
If the signal is lost, an attempt will be made to find it again and continue tracking. If there
are other signals on screen near the same amplitude, one of them may be found instead.
Signals near 0 Hz cannot be tracked effectively as they cannot be distinguished from the LO
feedthrough, which is excluded by intent from the search algorithm.
When Signal Track is On and the span is reduced, an automatic zoom is performed and the
span is reduced in steps so that the signal remains at the center of the display. If the span is
zero, signal track cannot be activated.
This function is intended to track signals with a frequency that is changing (drifting), and an
amplitude that is not changing. It keeps tracking if in continuous-sweep mode. If in
single-sweep mode, the N8201A only does one center frequency adjustment as necessary.
Signal tracking can also be used with the Δ (delta) pair marker function. This could be used
to measure the amplitude at a frequency offset, relative to the fundamental signal
amplitude, even if the fundamental is drifting. In this situation, the “tracking” function will
be done on the delta marker, not on the reference marker. So you would want to put the ref
marker on the frequency+offset, and put the Δ marker on the fundamental signal peak.
Then turn on signal tracking. The frequency difference between the two markers will stay
fixed. The Δ marker, on the fundamental, will track to the center of the display. The marker
readout value will show the amplitude delta between the two markers.
Key Path: FREQUENCY
Annunciation/Annotation: ST appears near the lower-left corner of the display. An
asterisk (*) may appear in the upper-right corner of the display while the N8201A whenever
the N8201A finds that it must retune in order to center the signal on the display.
State Saved: Saved in Instrument State.
Factory Preset: Off
Remote Command:
:CALCulate:MARKer[1]|2|3|4:TRCKing[:STATe] OFF|ON|0|1
:CALCulate:MARKer[1]|2|3|4:TRCKing[:STATe]?