Input Extensions (Keysight X-Series Analyzers)
This topic lists and describes the Input Extensions that are unique to the Keysight 89600 Series VSA with Keysight X-Series Signal Analyzers. The Input Extensions are configured in the Extensions tab of the dialog (click ). The Keysight X-Series Signal Analyzer must be configured as an Analyzer Configuration and that configuration set as the Current Analyzer Configuration. A parameter is changed by clicking the text box following the extension. For True/False values, a check in the check box sets the value to True. A cleared check box sets the value to False.
The Input Extensions typically do not need to be changed. The default values are set to perform standard measurements. Click to preset all input extension parameters across all logical instruments and channels.
Input Extensions with Keysight X-Series Signal Analyzer
The following are the extensions for the X-series analyzers:
Some extensions or some of the extension selections may not be available for all X-series analyzers. Extension parameters that are not available with the current hardware or channel configuration will be hidden by default. To view all parameters (including those that are not usable with the current hardware or channel configuration) check the "Show All" check box in the extensions tab.
Some extension selections also require the proper options to be installed in the analyzer. If the extension or extension selection is unavailable, the extension will not enable the parameter to be changed or entries in it that are not currently possible will be disabled.
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Parameter |
Values |
Default |
|---|---|---|
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Misc |
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Auto, Off, On, High |
Auto |
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True, False |
False |
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Auto, 32 Bits per Point, 64 Bits per Point |
Auto |
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N/A |
N/A |
|
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Bw15Hz, Bw60Hz |
Bw15Hz |
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Trigger 1 In, Trigger 2 In, Trigger 3 In, Precision |
Hardware dependent |
|
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String containing the name of the IF path |
Hardware dependent |
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Off, On |
On |
|
|
Off, On |
Off |
|
|
Off, On |
Off |
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Standard, Low Noise, Preselector Bypass, Full Bypass |
Preselector Bypass |
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Normal, Alternate |
Normal |
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Best Close In, Best Wide Offset , Fast Tuning, Balanced, Spur Avoidance |
Best Close In |
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RFIO 1, RFIO 2/RFIO FD, RFIO 3/RFIO HD/mmW A1/T-R, RFIO 4/mmW A2, RF Radio Frequency: A generic term for radio-based technologies, operating between the Low Frequency range (30k Hz) and the Extra High Frequency range (300 GHz). Input/ANT, mmW A3, mmW B1, mmW B2, mmW B3, IFIO 1, IFIO 2, RF Input2 |
Hardware dependent |
|
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Auto, Lowband, Narrowband, Medium, Wideband, Wideband Extended, Aux Wideband, External Wideband |
Auto |
|
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Off, On |
Off |
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| Parameters Influenced by the Measurement Type |
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| IF Offset Freq Auto |
Off, On |
On |
| IF Offset Manual Freq (Avoid Spur) |
±(MaxSignalPathBandwidth - Current Span)/2 |
0 |
| Influence Criteria |
Normal, Spectral Quality |
Normal |
| Influence Criteria Auto |
Off, On |
On |
|
Range |
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Range, Attenuation |
Range |
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Same as DIF path's min/max range |
0dB |
|
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Same as DIF path's min/max range |
-780dB |
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Same as DIF path's min/max range |
-780dB |
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Off, On |
Off |
Misc
Adc Dither
The Adc Dither parameter selects either to improve the distortion or signal-to-noise ratio measurement performance. Selecting Adc Dither will improve the measurement distortion performance but at the expense of decreased signal to noise ratio performance. Adc Dither is implemented by applying an out of band random dither signal to the input of the ADC Analog-to-Digital Converter.
This is the same as the Off mode.
Dither is turned off.
Dither is applied at 6% of full scale.
Dither is applied at 18% of full scale. The High setting is only valid for the PXA analyzer. In other X-Series analyzers the High mode is the same as the On mode.
‡ PXA analyzer: When using the PXA analyzer, the dither is only applied when the span setting is less than or equal to 25 MHz Megahertz: A unit of frequency equal to one million hertz or cycles per second. and when the Digital IF Signal Path parameter setting is either Auto, 10MHz or Narrow.
Baseband Adc Dither
This only applies to X-Series analyzers that have Option BBA Analog Baseband I/Q Inputs installed.
Turns on the Baseband Adc Dither.
Turns off the Baseband Adc Dither.
Capture Bit Packing
The Capture Bit Packing parameter specifies the resolution of the recorded measurement data. The Capture Bit Packing setting affects the available maximum capture time.
The VSA will use 32 bits/data point for measurement spans greater than 40 MHz and 64 bits/data point for measurement spans less than or equal to 40 MHz.
The hardware will capture complex data at 32 bits per complex data point (16 bits for the real part and 16 bits for the imaginary part). The data is converted to a floating point data type before saving to the disc file.
The hardware will capture complex data at 64 bits per complex data point (32 bits for the real part and 32 bits for the imaginary part). The data is converted to a floating point data type before saving to the disc file.
For measurement spans greater than 40 MHz, 32 bit packing is sufficient because at these bandwidths the input noise of the ADC will dominate the measurement results. However, for narrower spans the processing gain will drive down the noise floor so that the dominating factor will be the quantization noise introduced by 32 bit packing. In this case, 64 bit packing can be used to provide a lower noise floor for input signals.
However, when the dominating factor is the noise on the input signal or when a lower noise floor is not needed, bit packing can be switched to 32 bits/data point to enable longer recording times.
Extended Capture
Current XSA instruments allow up to 5M points (depending on the signal path) with a live acquisition. Starting with VSA20.0, the extended capture enhancement allows users to use deep capture capability (with DP2-capable DIF hardware) with live acquisitions. With this capability, the maximum capture length will go up to 134M.
This setting is transparent to the user. No Input Extension parameter is visible in the GUI, and nothing needs to be set for extended capture to be enabled. When the user requests more than 5M points, the VSA will automatically switch from a regular IQ Pairs request to a Deep Capture request where VSA will offload chunks of data directly from the XSA DIF board. Extended capture is recommended to be used with the VSA embedded inside an XSA instrument to avoid long transfer delays via LAN Local Area Network: A communications network that serves users within a local geographical area, typically over distances of around 100m. Wireless LANs use wireless communicaitons to network devices so there is no need for data cabling..
External Reference Lock Bandwidth
The External Reference Lock Bandwidth parameter is used to specify the external reference signal bandwidth. Set the External Reference Lock Bandwidth to when the external reference signal has superior phase noise.
The external reference BW is only applied to X-Series analyzers that have the low phase noise reference boards installed. The setting is overridden and the default value is applied for instruments that do not have the low phase noise reference board installed.
External Trigger Location‡
The External Trigger Location parameter specifies which external trigger port is to be used. Some Keysight X-Series Signal Analyzers provide additional external trigger input ports:
Specifies the Trigger 1 input port.
Specifies the Trigger 2 input port.
Specifies the Trigger 3 input port .
For wide bandwidth measurements.
The precision trigger is supported with the following models and IF paths (options):
- N9032B: 255 MHz (Opt B2X), 1 GHz Gigahertz: A frequency measurement which equals one billion hertz. (Opt R10), 1.5 GHz (Opt R15), and 2 GHz (Opt R20) IF paths.
- N9042B: 255 MHz (Opt B2X), 1 GHz (Opt R10), 1.5 GHz (Opt R15), 2 GHz (Opt R20), and 4 GHz (Opt R40) IF paths.
Trigger 1 In is the normal default. However, Trigger 3 In is the default for wideband hardware when Trigger 1 In is not possible for the widest bandwidth IF Path (e.g., N9040B-H1G).
For N9040B with Option H1G, when IF Path Auto is set On, the selected External Trigger Location influences the automatically determined signal path. When in Auto and using the N9040B-H1G, set External Trigger Location to either Trigger 1 In, Trigger 2 In, or Trigger 3 In. When External is selected for the Input Trigger Style, the VSA software will choose one of the signal paths that supports the chosen External Trigger Location (which may limit the bandwidth).
When IF Path is set equal to 1 GHz, External Trigger Location is limited to Trigger In 3 only. When IF Path is set less than 1 GHz, External Trigger Location is limited to Trigger 1 In or Trigger 2 In.
When IF Path is set greater than 1 GHz, the external trigger location is Aux Trig on the oscilloscope used as the external digitizer.
‡ Not available for Keysight CXA analyzers.
IF Path
The IF Path parameter is used to specify which IF signal path to use. When IF Path Auto is On, the value is set by VSA software. The parameter value is a string containing the name of the IF path. This name is formatted as three fields separated by underscore: bandwidth_pathType_model.
- Bandwidth - an integer value in Hz. This is a required field.
- PathType - StandardN or AlternateN, where N is an integer greater than or equal to 1. Path type is model specific. Alternate paths are available depending on instrument model and options. This field is optional for the default pathType, which is Standard1.
- Model- the instrument model. When setting IF Path, this field is optional for the default value, which is the instrument model of the current hardware configuration.
Only bandwidth is returned for a standard IF path. Bandwidth and path type are returned for an alternate path. In most cases the value of IF Path will be only the bandwidth (e.g., “1000000000” for a standard 1 GHz IF path).
IF Path Auto
The IF Path Auto parameter is used to specify how the measurement analog IF path is selected.
The VSA automatically selects the best standard IF path for the specified measurement span, trigger type and segmented capture.
Path is set by IF Path parameter.
Instrument User Corrections
The Instrument User Corrections parameter specifies whether the input channel corrections defined in the X-Series Analyzer are applied to data captured from the analyzer. Any correction (Correction 1 - Correction 6) designated as On will be applied when Instrument User Corrections is set to On.
The Instrument User Corrections parameter works with the RF input and the External Mixer input (PXA only). This parameter does not apply to the Baseband or I+jQ inputs.
When using the Auto Range feature with the RF Input, Instrument User Corrections must be set to in order for Auto Range to work correctly.
This allows you to recall vendor corrections for external mixers into the X-Series Analyzer and have these corrections applied when using the 89600 VSA software to connect to the analyzer.
LO Dither
This only applies to X-Series analyzers that have Option H1G 1 GHz Analysis Bandwidth installed.
Turns on the LO Dither.
Turns off the LO Dither.
Microwave Path Control
The Microwave Path Control parameter is used to bypass the Microwave Preselector signal path. The Microwave Path Control parameter only has an effect when Option MPB is installed. The Microwave Preselector bypass should be selected for measurements when the IF amplitude and phase flatness is the most important signal characteristic, such as for demodulation measurements when the measurement span is greater than a few megahertz.
The Microwave Preselector is included in the measurement signal path for the high frequency bands.
Enable the low noise path for the high frequency bands. This selection requires option LNP.
The Microwave Preselector switching is not included in the measurement signal path for the high frequency bands. This selection requires option MBP.
The Microwave Preselector switching is not included in the measurement signal path, and the low noise path is enabled, for the high frequency bands. This selection is available if options LNP and MBP are present. This path is not calibrated unless option FBP is present.
The Full Bypass microwave path control can give better sensitivity, especially at higher frequencies. With the low noise path enabled and the Preselector bypassed there is less loss in the signal path thus improving instrument sensitivity. See the instrument-specific data sheet or documentation for more information.
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Care should be taken when in Full Bypass mode to avoid high signal levels which might damage the mixer. See the instrument-specific data sheet or documentation for more information. |
Mixer Mode
The Mixer Mode parameter switches the LO mixing mode from high-side to low-side and vice versa. This selection is not available with BBIQ or external mixer inputs.
This is the default LO mixing mode of the analyzer.
This switches the LO mixing mode from default mode to the alternate side.
Alternate mixer mode is not supported with PXE analyzers.
Phase Noise Optimization
The Phase Noise Optimization setting will affect the phase noise distribution on the VSA's LO. The Phase Noise Optimization functions the same but the applicable frequency ranges are different depending on the particular X-series model:
CXA analyzer
- Option 503 or 507: Not Available
- Option 513 or 526:
For measurement analysis regions less than 25 kHz kiloHertz: A radio frequency measurement (one kilohertz = one thousand cycles per second). from the input signal.
For measurement analysis regions greater than 25 kHz from the input signal.
CXA-m analyzer
For measurement analysis regions less than 25 kHz from the input signal.
For measurement analysis regions greater than 25 kHz from the input signal.
Provides faster settling but a higher phase noise level.
MXE analyzer
For measurement analysis regions less than 25 kHz from the input signal.
For measurement analysis regions greater than 25 kHz from the input signal.
PXE analyzer
For measurement analysis regions less than 75 kHz from the input signal.
For measurement analysis regions greater than 100 kHz from the input signal.
Provides faster settling but a higher phase noise level. Same behavior as Balanced when using the PXE.
For measurement analysis regions that need a balance between the best close-in and the best wide offset. Same behavior as Fast Tuning when using the PXE.
MXA/EXA analyzer
For measurement analysis regions within 20 kHz of the input signal.
For measurement analysis regions greater than 20 kHz from the input signal.
: For measurement analysis regions that need a balance between the best close-in and the best wide offset. Only available with MXA option EP2
PXA analyzer
Select this option if your measurement analysis region is within 140 kHz of the input signal.
Select this option if your measurement analysis region is greater than 160 kHz from the input signal.
UXA analyzer
Select this option if your measurement analysis region is less than 600 kHz of the input signal.
Select this option if your measurement analysis region is greater than 800 kHz from the input signal.
Select Best Wide Offset for the best MER result when using a UXA or PXA to make DOCSIS3.1 Downstream measurements (this could improve MER by 1-2dB).
Provides faster settling but a higher phase noise level.
Optimizes for balance between narrow and wide offset. Select this option if your measurement analysis region is less than 600 kHz and to avoid spurs above -70 dBc deciBels referenced to the carrier: A technique for expressing a power measurement in logarithmic form using the carrier power as a reference..
Optimizes for spur avoidance. Select this option if your measurement analysis region is less than 600 kHz and to avoid spurs above -90 dBc.
RF Input Port
The RF Input Port parameter selects one of the analyzer's RF Input/Output ports. A port is only selectable if the connected hardware supports it. The default selection is hardware dependent.
RF Input/Output port. It provides half or full duplex IO capability depending on the hardware.
RF Input/Output port. It provides half or full duplex IO capability depending on the hardware.
RFIO FD: M9420A VXT full duplex IO port. See M9420A Input Extensions.
RF Input/Output port. It provides half or full duplex IO capability depending on the hardware.
RFIO HD: M9420A/M9421A VXT half duplex IO port. See M9420A/M9421A Input Extensions.
mmW A1: E7760A Wideband Transceiver mmWave A1 port. See E7760A Input Extensions.
TR: M8920A Radio Test Set T/R port. See M8920A Input Extensions.
RF Input/Output port. It provides half or full duplex IO capability depending on the hardware.
mmW A2: E7760A Wideband Transceiver mmWave A2 port. See E7760A Input Extensions.
RF Input port.
ANT: M8920A Radio Test Set antenna port. See M8920A Input Extensions.
RF Input: N9048B
E7760A Wideband Transceiver mmWave A3 port. See E7760A Input Extensions.
E7760A Wideband Transceiver mmWave B1 port. See E7760A Input Extensions.
E7760A Wideband Transceiver mmWave B2 port. See E7760A Input Extensions.
E7760A Wideband Transceiver mmWave B3 port. See E7760A Input Extensions.
E7760A Wideband Transceiver IF IO port 1. See E7760A Input Extensions.
E7760A Wideband Transceiver IF IO port 2. See E7760A Input Extensions.
RF Input2 port.
RF Input2 is not supported with the N9048B at this time.
Signal Path (Deprecated)
This property is deprecated. Use IF Path and IF Path Auto to set the signal path.
The Signal Path parameter is used to specify the measurement analog signal path. The PXA analyzer provides up to four possible signal paths depending on the options installed, each with a different analog filter bandwidth and number of ADCs. Each signal path is optimized for the maximum available span. The available signal paths are determined by the installed options.
The VSA determines the optimal signal path for the specified measurement span.
The VSA restricts the maximum span to 10 MHz and uses the 10 MHz signal path. No option is required for this setting.
The VSA restricts the maximum span to 25 MHz and uses the 25 MHz signal path. Option B25 is required for this setting.
The VSA restricts the maximum span to 40 MHz and uses the 40 MHz signal path. Option B40 is required for this setting.
The VSA restricts the maximum span to 140MHz, 255MHz, 510MHz and uses the respective signal paths, with respective options B1X, B2X, B5X.
The VSA restricts the maximum span to 160 MHz and uses the 160 MHz signal path. Option B1Y is required for this setting.
The VSA restricts the maximum span to 1GHz and uses the 1GHz signal path. Option H1G is required for this setting.
The VSA's maximum span is extended beyond 1GHz using the N9041B UXA's optional External Digitizer Control (EDC). See N9041B Option EDC System Configuration for more information.
If a Digital IF Signal Path setting is chosen and the required option is not installed, the VSA will select the best available setting.
For N9040B with Option H1G, , when Signal Path is set to Auto, the selected External Trigger Location influences the automatically determined signal path. When in Auto and using the N9040B-H1G, set External Trigger Location to either Trigger 1 In, Trigger 2 In, or Trigger 3 In. When External is selected for the Input Trigger Style, the VSA software will choose one of the signal paths that supports the chosen External Trigger Location (which may limit the bandwidth).
When Signal Path is set to Aux Wideband, External Trigger Location is limited to Trigger In 3 only. When Signal Path is set to Lowband, Narrowband, Medium, or Wideband, External Trigger Location is limited to Trigger 1 In or Trigger 2 In.
When Signal Path is set to External Wideband, the external trigger location is Aux Trig on the oscilloscope used as the external digitizer.
Wideband IF Output
The Wideband IF Output parameter turns the wideband IF output of the analyzer on/off when available.
Turns off the wideband IF output pf the XSA analyzer.
Turns on the wideband IF output of the XSA analyzer.
Parameters Influenced by the Measurement Type
IF Offset Freq Auto
Select whether IF Offset should be automatically controlled.
IF Offset Freq and IF Offset Freq Auto are only supported for some instrument and IF Path combinations (e.g. UXA with Option H1G and 1 GHz IF Path selected).
The actual IF Offset Freq used internally will not be updated in the IF Offset Manual Freq property when Auto is On.
When IF Offset Freq Auto is On, no indication is given in the VSA software about whether actual spur dodging is occurring or not.
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- In 'Auto' mode, the Optimization Criteria will determine the auto behavior.
- - In 'Manual' mode, the IF Offset Manual Freq value will be used.
IF Offset Manual Freq (Avoid Spur)
Select an IF offset (in hertz) to use when IF Offset Freq Auto is set to Manual. This allows the user to set a specific offset for the IF in Hertz which will then be compensated for by a corresponding offset in the reverse direction after the digitizer so that the requested center frequency is still at the center. This can be useful for moving the position of spurs and images relative to the desired center frequency. See About IF Offset Freq and Spur Avoidance for more information.
The limits for this value are +/- ((max span - current span) / 2). The parameter priority is Center, Span, and then IF Offset Freq, so the IF Offset Freq will be coerced if needed as the span is changed. If the user changes IF Offset Freq while IF Offset Freq Auto is On, it will internally force IF Offset Freq Auto to Off. A positive value shifts the spur to the right in the spectrum display and a negative value shifts it to the left. The IF Offset Freq is coerced to 0 if the IF Path Auto property is set to On (even though it may internally choose to use a non-zero value). This parameter is for the manually entered value and does not reflect what the auto-chosen value might be when Auto is on.
IF Offset Freq and IF Offset Freq Auto are only supported for some instrument and IF Path combinations (e.g. UXA with Option H1G and 1 GHz IF Path selected).
Influence Criteria
Select the criteria for how to influence other parameters that are part of the 'Parameters Influenced by the Measurement Type' category. This influences what the IF Offset behavior will be when IF Offset Freq Auto is set to Auto.
- - IF Offset is set to 0.
- - Avoids spurs if the span is small enough to internally control the IF Offset to avoid spurs.
Influence Criteria Auto
Select whether the influence criteria is automatically determined based upon the current type of measurement.
- - Power spectrum-based measurements will choose to use the 'Spectral Quality' criteria. Otherwise, the 'Normal' criteria will be used.
- - Manually select the Influence Criteria.
Range
The Range settings display the current value of the X-Series Signal Analyzer's parameters such as Mechanical Attenuation, IF Gain and Preamplifier. When Control Method is set to Attenuation, the Range settings become editable.
Control Method
Range Control Method allows the user to select the control mode to either Range or Attenuation. By default, it is set to Range method. By selecting Attenuation method, the user is allowed to change any of the range related parameters such as mechanical attenuation, IF gain, preamp state, or mixer level.
In Attenuation control mode, the Auto Range function will be disabled.
If the Range Control Method is set to Range, the overall input level range is set using the standard Analog Range property in the application. The mapping of a given Range value to the setup of individual hardware component settings is done by the application and cannot be explicitly set when using this method, and other range related parameters cannot be set when using this method (but will reflect the values chosen by the application for a given Range value).
If the Range Control Method is set to Attenuation, the user is allowed to explicitly change any of the range-related parameters such as Mechanical Attenuation, IF Gain andPreamplifier.
IF Gain (dB)
If Range: Control Method is set to Range, this will be set to a nominal IF gain value used by VSA ranging algorithm.
If Range: Control Method is set to Attenuation, this value can be set by the user. The min/max values will be coerced to the currently selected DIF path’s min/max values. In both modes, this will show the current value that is being set by VSA.
Mechanical Attenuation (dB)
If Range: Control Method is set to Range, this will be set to a nominal mechanical attenuation value used by VSA ranging algorithm.
If Range: Control Method is set to Attenuation, this value can be set by the user. The min/max values will be coerced to the currently selected DIF path’s min/max values. In both modes, this will show the current value that is being set by VSA.
Mechanical Full Range Attenuation (dB)
If Range: Control Method is set to Range, this will be set to a nominal value of 20dB. This is only available with N9041B when used with RF Input2.
If Range: Control Method is set to Attenuation, this value can be set by the user. The min/max values will be coerced to the currently selected DIF path’s min/max values. In both modes, this will show the current value that is being set by VSA.
Full Range refers to this attenuation being supported for the full frequency range of the selected input.
Preamplifier
Select whether to turn on a preamplifier in the signal path.
Preamplifier is off.
This is a normal preamplifier that may have a frequency limit to it (depending upon the option) and is also not usable when using the low noise or full bypass microwave paths.
This is a low noise amplifier (or preamplifier) that is usable at all frequency ranges and all microwave paths. Whether this choice is available will depend upon the instrument model and hardware options present.
See Also
