External Reference Lock Bw - Keysight x-series User Reference Manual

External Reference Lock BW

This control lets you adjust the External Reference phase lock bandwidth. This control is available in some
models of the X-Series.
The PXA variable reference loop bandwidth allows an external reference to be used and have the analyzer
close-in phase noise improved to match that of the reference. This could result in an improvement of tens
of decibels. The choice of "Wide" or "Narrow" affects the phase noise at low offset frequencies, especially
4 to 400 Hz offset. When using an external reference with superior phase noise, we recommend setting the
external reference phase-locked-loop bandwidth to wide (60 Hz), to take advantage of that superior
performance. When using an external reference with inferior phase noise performance, we recommend
setting that bandwidth to narrow (15 Hz). In these relationships, inferior and superior phase noise are with
respect to −134 dBc/Hz at 30 Hz offset from a 10 MHz reference. Because most reference sources have
phase noise behavior that falls off at a rate of 30 dB/decade, this is usually equivalent to −120 dBc/Hz at
10 Hz offset.
Key Path
Scope
Remote Command
Example
Dependencies
Preset
State Saved
Initial S/W Revision
Modified at S/W Revision
Output Config
Accesses keys that configure various output settings, like the frequency reference output, trigger output
and analog output.
Key Path
Backwards Compatibility
Notes
Initial S/W Revision
EMI Receiver Mode Reference
Input/Output, Freq Ref In
Mode Global
[:SENSe]:ROSCillator:BANDwidth WIDE|NARRow
[:SENSe]:ROSCillator:BANDwidth?
ROSC:BAND WIDE
Still available with Internal or Pulse selected, to allow setup for when External is in use. However,
the setting has no effect if the Internal Reference is in use (Freq Ref In set to Internal, Pulse, or
SENSE:INT or SENSE:PULSE).
This key only appears in analyzers equipped with the required hardware.
This is unaffected by a Preset but is set to Narrow on a "Restore Input/Output Defaults" or "Restore
System Defaults -> All"
Saved in Input/Output state.
A.04.00
A.14.00
Input/Output
In ESA there was not a user interface to enable the Video Output (Analog Output), Trigger Output, or
Gate Output. In the X-Series each of these physical connectors requires configuration, thus the
user interface has been added for X-Series, along with the potential for an output you think is
always on to be switched off.
Prior to A.02.00
4 Input/Output Functions
Input/Output
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