Markers


Markers provide a numerical readout of measured data, a search capability for specific values, and can change stimulus settings. There are 15 regular markers and one Reference marker (used with Delta markers) available per trace. This topic discusses all aspects of markers.

Note: Marker Readout can be turned ON/OFF and customized from the Customize Display dialog box. Learn more.

Note: Marker Readout can be turned ON / OFF and customized from the View/Display menu. Learn more.

Other Analyze Data topics

Creating  and Moving Markers

How to Create Markers

Using Hardkey/SoftTab/Softkey

Using a mouse

  1. Press Marker > Marker 1-7 / Marker 8-15 / Reference.

  2. Click left side Marker N or Reference small button.

  1. Move the cursor on a trace.

  2. Right-click on the trace then select Add Marker....

Moving a Marker

To move a marker, make the marker active by selecting its number in any of the previous 3 methods. The active marker appears on the analyzer display as Ñ. All of the other markers are inactive and are represented on the analyzer display as D. Then change the stimulus value using any of the following methods:

Marker Setup

How to set the Marker Setup.

Using Hardkey/SoftTab/Softkey

Using a mouse

  1. Press Marker > Marker Setup.

  2. Set the value or select desired setting for each softkey.

  1. Move the cursor on a marker.

  2. Right-click on the marker then select Marker....

Marker dialog box help

 

Marker  Specifies the current (active) marker number that you are defining.

On  Check to display the marker and corresponding data on the screen.

Stimulus  Specifies the X-axis value of the active marker. To change stimulus value, type a value, use the up and down arrows, click in the text box and use the front-panel knob, or drag the marker on the screen.

Note: When the sweep type is set to CW Time, the marker can not be set to 0  (first point of the trace on the x-axis) because the marker indicates the time to acquire the first point of the trace.

Delta (and Reference) Markers  Check to make the active marker display data that is relative to the reference (R) marker.  There is only one reference marker per trace. All other markers can be regular markers or delta markers. When a delta marker is created, if not already displayed, the reference marker is displayed automatically. A delta marker can be activated from the Marker dialog box or the Marker Toolbar. See Also: Number of General Purpose and Reference Markers.

Discrete Marker  Check to display values at only the discrete points where data is measured. Clear to display values that are interpolated from the data points. The interpolated marker will report y-axis data from ANY frequency value between the start and stop frequency.

Fixed  Check to cause the marker to have a fixed X-axis and Y-axis position based on its placement on the trace when it was set to fixed. It does NOT move with trace data amplitude. It can be scrolled left and right on the X-axis by changing the marker stimulus value. Use this marker type to quickly monitor "before and after" changes to your test device. For example, you could use fixed markers to record the difference of test results before and after tuning a filter.

Clear the box to create a Normal marker, which has a fixed stimulus position (X-axis) and responds to changes in data amplitude (Y-axis). It can be scrolled left and right on the X-axis by changing the marker stimulus value. Use this marker type with one of the marker search types to locate the desired data.

(Marker) Format  Displays the marker data in a format that you choose. The Trace Default setting has the same marker and grid formats. Choose from the following:

Log/Phase

Log Mag

Real

Fahrenheit

Linear/Phase

Linear Mag

Imaginary

Celsius

Real/Imag

Phase

Phase Unwrapped

Noise

R+jX (complex impedance)

SWR

Phase Positive

 

G+jB (complex admittance)

Delay

Kelvin

 

Noise Marker Format ( SA measurement classes only) - For comparison purposes, electronic noise measurements are often displayed as though the measurement was made in a 1 Hz Res BW. However, making an actual measurement at a 1 Hz Res BW is impossible, and at 10 Hz, extremely slow.

A Noise Marker mathematically calculates the noise measurement at that single data point as though it were made using a 1 Hz bandwidth.

To accurately measure noise, the Noise Marker should NOT be placed on, or too close to, a signal. The distance from a signal depends on several factors. To know if an accurate reading is being made, move the Noise Marker until consistent measurements are displayed in adjacent data points.

All Off  Switches OFF all markers on the active trace.

Coupled Markers

The coupled markers feature causes markers on different traces to line up with the markers on the selected trace. Markers are coupled by marker number, 1 to 1, 2 to 2, 3 to 3, and so forth. If the x-axis domain is the same (such as frequency or time), coupling occurs. Trace markers in a different x-axis domain will not be coupled. If a trace marker has no marker to couple with on the selected trace, the marker remains independent.

Coupling Method - Determines the scope of coupling. Choose from the following:

  • All - A marker on one trace is coupled to the same-numbered markers on all channels, all windows and all traces.

  • Channel - A marker on one trace is coupled to the same numbered markers on traces which share the same channel number as the original trace.

Coupled Markers Model

This model simulates the use of coupled markers in the analyzer :

        

  1. Click Trace A or Trace B

  2. Click Coupled Markers

  3. Notice the following:

    • Markers on the unselected trace move to the x-axis position of the selected trace.

    • If a marker number on the unselected trace has no corresponding marker on the selected trace, no movement occurs for that marker.

  1. Click Reset to run the model again. There is no Reset for coupled markers on the analyzer .

Searching with Markers

You can use markers to search and return data for the following trace criteria:

How to Search with Markers

Using Hardkey/SoftTab/Softkey

Using a mouse

  1. Press Search > Main / Peak / Target / Multi Peak & Target / Bandwidth & Notch / Compression & Saturation / Normal Op Pt. 

  1. Move the cursor on a marker.

  2. Right-click on the marker then select Search...to show the Marker Search Dialog box for define the search parameters.

  3. From Search Type of Marker Search dialog box, select the desired search function.

  4. Press Execute or check Tracking. Learn more.

Marker Search dialog box help

 

Marker  Specifies the marker that you are defining. Not available for search types that deploy specific markers.

Search Range  Defines the area where the marker can move or search. For full span, the marker searches for specified values within the full measurement span. For user span, the marker searches for specified values within a measurement span that you define. Learn more about Search Range.

Search Type

Note  You must either press Target Search or check Tracking to initiate all search types.  If there is no valid data match for the search type, the marker will not move from its current position.

  • Target Search  Click to cause the marker to search for the specified criteria.

  • Tracking  Check to cause the marker to search for the specified criteria with each new sweep. The searches begin with the first sweep after Tracking has been checked, based on the current search type and domain information. Therefore, make sure that the search criteria are in the desired state before using the data. You cannot manually change the stimulus setting for a marker if Tracking is selected for that marker.

Maximum  Marker locates the maximum (highest) data value.

Minimum  Marker locates the minimum (lowest) data value.


Peak - See below.

Next Peak - Marker locates the peak with the next lower amplitude value relative to its starting position.

Peak Right - The marker locates the next valid peak to the right of its starting position on the X-axis.

Peak Left - The marker locates the next valid peak to the left of its starting position on the X-axis.

Multi Peak - A function that search for peaks that match the multi-peak search excursion value and multi-peak polarity value. Learn more about Multi Peak Search.

  • Threshold  - Minimum amplitude (dB). To be considered valid, the peak must be above the threshold level. The valley on either side can be below the threshold level.

  • Excursion  The vertical distance (dB) between the peak and the valleys on both sides. To be considered a peak, data values must "fall off" from the peak on both sides by the excursion value.


Target - A function that searches for a target that matches the pre-defined target value and transition types (positive, negative or both (positive and negative)) and then moves the marker to that target. Learn more about Multi Target Search.

Target Left - A function executes the search from the current marker position to the smaller stimulus values and moves the marker to first target encountered.

Target Right - A function executes the search from the current marker position to the larger stimulus values and moves the marker to first target encountered.

Multi Target - A function that search for targets that are of the multi-target value and multi target transition value. Learn more about Multi Target Search.

    • Target - Value in dB.


Compression - A function used the active marker to find the specified gain Compression Level. Learn more about Compression Search.

  • Compression - Value in dB.


Bandwidth and Notch searches are accessed by pressing Search > Bandwidth & Notch > BW Ref to or Search > Bandwidth & Notch > Notch Ref to.

Bandwidth - A function for determining the bandwidth of the trace, center frequency, cut-off points (on the higher frequency and the lower frequency sides), Q and insertion loss based on the position of the active marker (if search mode set to Marker) or the peak marker (if search mode set to Peak). Learn more about Bandwidth Search.

  • Bandwidth peak mode search
    • If level is negative, search is relative to the maximum peak.
    • If level is positive, search is relative to the minimum peak.
    • Bandwidth level in dB.

Notch -  A function is used to obtain the bandwidth, center frequency, cutoff points (high-frequency side and low-frequency side), Q and insertion loss of a trace based on the position of the active marker (if search mode set to Marker) or the peak (if search mode set to Peak). Learn more about Notch Search.

  • Notch peak mode search
    • If level is negative, notch search is relative to the minimum peak.
    • If level is positive, notch search is relative to the maximum peak.
    • Notch level in dB.

The default behavior for searches based on the active marker or peak marker can be set using the Marker: On Preset, set BW/Notch search reference to Peak preference.


Power Saturation - Learn more about PSAT Search.

  • PMax Back-off -Value in dB.


Normal Operating Pt - The output power where the input is offset from the back-off input power by the Pin Offset. Learn more about PNOP Search.

  • Back-off - Value in dB.

  • Pin Offset - X-axis value in dB.

 


Spurious Search (Phase Noise only)

Phase Noise marker searches are accessed by pressing Search > Spurious or by selecting the search marker from the Search Type pulldown menu in the Marker Search dialog.

The Phase Noise application has marker search function types similar to a standard channel. In addition, it has marker search types specific to a Phase Noise channel. Spur analysis must be enabled to use the Spurious search functions. See Enable Spur Analysis.

Spurious Search - Searches for spurious signals based on spurious settings.

Spurious Right >> Search - Searches for the next spurious signal to the right.

<< Spurious Left Search - Searches for the next spurious signal to the left.

Multi Spurious Search - Searches for multiple spurious signals.

Spur Sensibility - Sets the spurious sensibility number. Learn more.

 

Maximum and Minimum Search

How to create Maximum and Minimum Search

Using Hardkey/SoftTab/Softkey

Using a mouse

  1. Press Search > Main.

  2. Click Max Search or Min Search.

  3. Optionally click Tracking to search for the specified maximum or minimum level with each sweep. Learn more.

  1. Move a cursor on a marker.

  2. Right-click on the marker and then select Search....

  3. From Search Type of Marker Search dialog box, select Maximum / Minimum.

  4. Press Execute or check Tracking. Learn more.

You can search for the maximum or minimum measured value on the trace and move a marker to that point.

Search for maximum (Max Search)

Move active marker to point on trace where measured value is greatest.

Search for minimum (Min Search)

Move active marker to point on trace where measured value is lowest.

Note: When the data format is in Smith chart or polar format, execute the search only for the main response value.

Peak Search

How to create Peak Search

Using Hardkey/SoftTab/Softkey

Using a mouse

  1. Press Search > Peak.

  2. Click Peak Search to show the markers on the peak.

  3. Click Peak Right >> Search, << Peak Left Search or Next Peak Search to move the marker to the peak.

  4. Click Threshold to enter the value of peak threshold.

  5. Click Excursion to enter the lower limit value of peak excursion.

  6. Click Peak Polarity to select a peak polarity.

  7. Optionally click Tracking to search for the specified peak level with each sweep. Learn more.

  1. Move a cursor on a marker.

  2. Right-click on the marker and then select Search....

  3. From Search Type of Marker Search dialog box, select Peak / Peak Left / Peak Right / Next Peak.

  4. Enter the value of Threshold and Excursion.

  5. Press Execute or check Tracking. Learn more.

A peak is a measurement point whose value is greater or smaller than the adjoining measurement points on its right and left sides. Peaks are classified into the following two types depending on the difference in magnitude from the measurement points on either side of it.

What Is a "Peak"?

You define what the analyzer considers a "peak" by selecting the following two peak criteria settings:

Peak Polarity:

Definition:

Positive

A peak whose measured value is greater than those of the measurement points on either side of it.

Detect positive peaks which are larger than Threshold.

Negative

A peak whose measured value is smaller than those of the measurement points on either side of it.

Detect negative peaks which are smaller than Threshold.

Both

A peak whose measured value is smaller and greater than those of the measurement points on either side of it.

Threshold value is not used when polarity is set to both.

About Peak Excursion Value

The peak excursion value is the smaller of the differences in measured values from the adjoining peaks of the opposite polarity.

Executing a Peak Search

The following 3 methods are available for executing the peak search:

Next Peak

Moves the marker to the maximum peak when peak polarity is Positive or Both.

Moves the marker to the minimum peak when peak polarity is Negative.

Peak Left

Executes the search from current marker position to the smaller stimulus values and moves the marker to first peak encountered.

Peak Right

Executes the search from current marker position to the larger stimulus values and moves the marker to first peak encountered.

Note: Peak right, peak left and next peak may not be tracked. If these searches are selected and then tracking is turned on, the peak tracking is enabled.

         When the data format is in Smith chart or polar format, execute the search for the main response value of the two marker response values.

         Changing the settings of peak excursion value or peak polarity executes new search for multiple peak.

 

Example:

Threshold Setting: -10dB
Excursion Setting: 1dB
Scale = 1 dB / Division
Mouse over the graphic to find a valid peak.

 

Multi Peak Search

How to create Multi Peak Search

Using Hardkey/SoftTab/Softkey

Using a mouse

  1. Press Search > Multi Peak & Target.

  2. Click Multi Peak Search to show the markers on the multi peaks.

  3. Click Peak Threshold to enter the value of peak threshold.

  4. Click Peak Excursion to enter the lower limit value of peak excursion.

  5. Click Peak Polarity to select a peak polarity.

  6. Optionally click Tracking to search for the specified multi peak level with each sweep. Learn more.

  1. Move a cursor on a marker.

  2. Right-click on the marker and then select Search....

  3. From Search Type of Marker Search dialog box, select Multi Peak.

  4. Enter the value of Threshold and Excursion.

  5. Press Execute or check Tracking. Learn more.

The multi peak search function enables you to display markers on multiple peaks on traces. Depending on the number of detected peaks, markers 1 through 15 are displayed from the start frequency. The reference marker is not affected.

Multiple peak search has threshold, excursion and polarity as user defined values. This search may have tracking enabled.

When the multiple peak search is executed, previous markers search and tracking are disabled and the settings for the multiple peak search are used.

Note: Do not use individual marker settings or marker domain.

         Put markers on each valid peak, using up to 15 markers.

Target Search

How to create Target Search

Using Hardkey/SoftTab/Softkey

Using a mouse

  1. Press Search > Target.

  2. Click Target Search to enable the target search.

  3. Click Target Right >> Search or << Target Left Search to move the marker to the target.

  4. Click Target Value to input the value of target search.

  5. Click Transition to select a transition type.

  6. Optionally click Tracking to search for the specified target level with each sweep. Learn more.

  1. Move a cursor on a marker.

  2. Right-click on the marker and then select Search....

  3. From Search Type of Marker Search dialog box, select Target/Target Left/Target Right.

  4. Enter the value of the Target.

  5. Press Execute or check Tracking. Learn more.

The target search is a function that searches for a target that matches the pre-defined target value and transition types (positive, negative or both positive and negative) and then moves the marker to that target.

Target Transition Types

A target is a point that has a specific measured value on the trace. Targets can be divided into the 3 groups shown below depending on their transition type.

Transition Type:

Function:

Positive

The target value is larger than the measured value immediately preceding it.

Negative

The target value is smaller than the measured value immediately preceding it.

Both

The conditions for either Positive or Negative transition are satisfied.

Executing a Target Search

The following 3 methods are available for executing the target search:

Target Left

Executes the search from the current marker position to the smaller stimulus values and moves the marker to first target encountered.

Target Right

Executes the search from the current marker position to the larger stimulus values and moves the marker to first target encountered.

Multi Target

Executes the search for targets that are of the multi-target value and multi target transition value. See Multi Target Search.

Note: Target right and target left cannot have tracking enabled. If target left or target right is the selected search and then tracking is enabled, target tracking is enabled.

         When the data format is in Smith chart or polar format, execute the search for the main response value of the 2 marker response values.

         Changing the settings of target value or transition type executes new search for multiple target.

 

The marker moves to the first occurrence of the Target value to the right of its current position. Subsequent presses of the Target Search softkey cause the marker to move to the next value to the right that meets the Target value. When the marker reaches the upper end of the stimulus range, it will "wrap around" and continue the search from the lower end of the stimulus range (left side of the window).

Multi Target Search

How to create Peak Search

Using Hardkey/SoftTab/Softkey

Using a mouse

  1. Press Search > Multi Peak & Target.

  2. Click Multi Target Search to show the markers on the multi target.

  3. Click Target Value to enter the value of target.

  4. Click Transition to select a transition type.

  5. Optionally click Tracking to search for the specified multi target level with each sweep. Learn more.

  1. Move a cursor on a marker.

  2. Right-click on the marker and then select Search....

  3. From Search Type of Marker Search dialog box, select Multi Target.

  4. Enter the value of the Target.

  5. Press Execute or check Tracking. Learn more.

The multi target search is a function that searches for targets that match to pre-defined target value and transition types (positive, negative or both of positive and negative) and displays markers on the targets being searched.

Depending on the number of detected targets, markers 1 through 15 are displayed from the start frequency. The reference marker is not affected.

When the multi target search is executed, search and tracking settings for markers 1 through 15 are ignored and the settings for the multi target search are used.

Note: Put markers on each found target value, using up to fifteen markers. Reference marker is not affected. Do not use individual marker settings or marker domain. Search range is applied.

Multiple target search has target and transition types as user defined values. This search may have tracking enabled. When this search is executing, previous marker searches are disabled.

Bandwidth and Notch Search

Bandwidth and notch search behavior depends on whether the preference called Marker: Use single marker for marker search is set or not. When set, only one marker is used for a marker search. Sub markers are displayed and used for Bandwidth and Notch searches. When cleared, multiple markers are used for a marker search. The default is cleared.

How to create Bandwidth and Notch Search

Using Hardkey/SoftTab/Softkey

Using a mouse

  1. Press Search > Bandwidth & Notch.

  2. Click left side Bandwidth Search or Notch Search small button to turn it ON/OFF.

  3. For Bandwidth search, click BW Ref To > Marker or Peak.

  4. For Notch search, click Notch Ref To > Marker or Peak.

  5. Specify the BW Level or Notch Level in dB from the peak or valley where bandwidth / notch is measured.

  6. Optionally click Tracking to search for the specified bandwidth or notch level with each sweep. Learn more.

  1. Move a cursor on a marker.

  2. Right-click on the marker and then select Search....

  3. From Search Type of Marker Search dialog, select Bandwidth or Notch.

  4. Specify the Level in dB from the peak or valley where bandwidth / notch is measured.

  5. Press Execute or check Tracking. Learn more.

Bandwidth Search

The bandwidth search is a function for determining the bandwidth of the trace, center frequency, cut-off points (on the higher frequency and the lower frequency sides), Q and insertion loss based on the position of the active marker or peak marker. The definitions of the parameters determined through the bandwidth search are shown in below.

 

Notch Search

The notch search function is used to obtain the bandwidth, center frequency, cutoff points (high-frequency side and low-frequency side), Q and insertion loss of a trace based on the active marker or peak marker position. The notch search function starts from the left side of the active marker position and ends when points that meet the conditions are found.

The figure and the table below shows the definition of parameters obtained by notch search function. The notch value in figure below must be specified by the user.

The following values are displayed for Bandwidth and Notch Search:

Bandwidth/Notch Parameter:

Definition:

Bandwidth (BW)

The difference in frequency between the higher frequency cut-off and lower frequency cut-off points (High - Low).

Center frequency (cent)

Frequency at the middle point between the lower frequency cut-off and higher frequency cut-off points. (High + Low)/2.

Lower frequency cut-off point (Low)

Lower frequency of 2 measurement points, both separated by the defined bandwidth / notch value from the active marker position.

Higher frequency cut-off point (High)

Higher frequency of 2 measurement points, both separated by the defined bandwidth / notch value from the active marker position.

Q

Ratio of Center Frequency to Bandwidth (Center Frequency / Bandwidth).

Insertion loss (loss)

The measured value of the position of the center frequency at the time the bandwidth/notch search is executed.

Compression Search

Uses the active marker to find the specified gain Compression Level.

Note: Valid ONLY for S21 (Gain) measurements with a Power Sweep.  

How to create Compresssion Search

Using Hardkey/SoftTab/Softkey

Using a mouse

  1. Press Search > Comp & Sat.

  2. Click Compression Search to turn ON/OFF.

  3. Specify the Comp Level in dB.

  4. Optionally click Tracking to search for the specified compression level with each sweep. Learn more.

  1. Move a cursor on a marker.

  2. Right-click on the maker and then select Search....

  3. From Search Type of Marker Search dialog box, select Compression.

  4. Enter the Y-axis (Power OUT) difference between the first point and the compression marker.

  5. Press Execute or check Tracking. Learn more.

Linear gain is defined as the Y-axis value (gain) of the first data point of the Search Domain (Full Span by default).

Marker > N - X-axis value and Y-axis value.

Comp Pin - Input power (marker X-axis value).

Comp Pout - Output power (Pin + gain).

Comp Level - Compression level found.

Comp. Not Found - Displayed when the requested compression level is not found.

 

About PSAT and PNOP Search

Compression measurements based on the Pout vs Pin curves are common in the satellite test industry. In the case of Travelling Wave Tube (TWT) amplifiers, PSAT markers identify the normal operating point near saturation, and the amplifiers are operated with the power slightly backed-off approximately 0.03 to 0.1 dB. For TWT amplifiers, the saturation curve always "folds over" and produces a maximum power out.

For Solid State Power Amplifiers (SSPA), the saturation is not as well defined. A common reference is the Normal Operating Point, which is a power backed-off by 8 to 10 dB from the maximum power. In this case, the normal operating point marker replaces the Psat with the PNOP values. Also, because the backoff is important, the backoff output and input powers are displayed (PBO Out), (PBO in) as well as gain at back off (PBO Gain).

Power Saturation (PSAT) Search

If the Marker: Use single marker for marker search preference is cleared, this search uses Markers 1, 2, and 3 to quickly identify output power saturation parameters of an amplifier. If the Marker: Use single marker for marker search preference is set, then only one marker is used for the search and 2 notational markers are displayed. The notational markers may not be moved. These markers are for display purposes only.

Back-off is a point at which the output power is sufficiently lower than the saturated output power so that the device under test behaves in a more linear fashion.

Note: Valid ONLY for Power IN vs Power OUT measurements.  

How to make Power IN (X-axis) vs Power OUT (Y-axis) measurement

Using Hardkey/SoftTab/Softkey

  1. Press Preset.

  2. Press Sweep > Main > Sweep Type.

  3. Select Power Sweep.

  4. Press Trace > Trace Setup > Measure... and set Trace Meas to "B" Receiver

  5. Connect DUT input to port 1.

  6. Connect DUT output to port 2.

 

How to create PSAT Search

Using Hardkey/SoftTab/Softkey

Using a mouse

  1. Press Search > Comp & Sat.

  2. Click left side Saturation Search small button to turn ON/OFF.

  3. For PMax Back-Off, enter the Y-axis (Power OUT) difference between the Max Power marker (3) and the Back-off marker (2).

  4. Optionally click Tracking to search for the specified power saturation level with each sweep. Learn more.

  1. Move a cursor on a marker.

  2. Right-click on the marker and then select Search > Search....

  3. From Search Type of Marker Search dialog box, select Power Saturation.

  4. For PMax Back-Off, enter the Y-axis (Power OUT) difference between the Max Power marker (3) and the Back-off marker (2).

  5. Press Execute or check Tracking. Learn more.

This setting uses three markers to calculate and display 10 values.

The three markers:

The 9 displayed values:

Param

Description

Calculated from...

PSat Out

Output power at the saturation point.

Marker 2 Y-axis value

PSat In

Input power at the saturation point.

Marker 2 X-axis value

Gain Sat

Gain at the saturation point.

Psat Out - Psat In

Comp Sat

Compression at the saturation point.

Gain Sat - Gain Linear

PMax Out

Maximum output power.

Marker 3 Y-axis value

PMax In

Input power at the maximum output power.

Marker 3 X-axis value

Gain Max

Gain at the maximum output power.

PMax Out - PMax In

Comp Max

Compression at the maximum output power.

Gain Max - Gain Linear

Gain Linear

Linear gain at the first data point.

Marker 1 - Y-axis value MINUS X-axis value

Power Normal Operating Point (PNOP) Search

If the Marker: Use single marker for marker search preference is cleared, this search uses Markers 1, 2, 3, and 4 to quickly identify Normal Operating Point parameters of an amplifier. If the Marker: Use single marker for marker search preference is set, then only one marker is used for the search and 2 notational markers are displayed. The notational markers may not be moved. These markers are for display purposes only.

Back-off is a point at which the output power is sufficiently lower than the saturated output power so that the device under test behaves in a more linear fashion.

The power normal operating point is the output power where the input is offset from the back-off input power by the Pin Offset.

Note: Valid ONLY for Power IN vs Power OUT measurements.

See Power Saturation to learn how to make a Power IN (X-axis) vs Power OUT (Y-axis) measurement.

How to create PNOP Search

Using Hardkey/SoftTab/Softkey

Using a mouse

  1. Press Search > Normal Op Pt.

  2. Click left side Normal OP Search small button to turn ON/OFF .

  3. For Back-Off, enter the Y-axis (Power OUT) difference between the Max Power marker (3) and the Back-off marker (2).

  4. For Pin Offset, enter the X-axis (Power IN) difference between Back-off marker (2) and PNOP marker (4).

  5. Optionally click Tracking to search for the specified power normal operating point level with each sweep. Learn more.

  1. Move a cursor on a marker.

  2. Right-click on the marker and then select Search > Search....

  3. From Search Type of Marker Search dialog box, select Normal Operating Pt.

  4. For Back-Off, enter the Y-axis (Power OUT) difference between the Max Power marker (3) and the Back-off marker (2).

  5. For Pin Offset, enter the X-axis (Power IN) difference between Back-off marker (2) and PNOP marker (4).

  6. Press Execute or check Tracking. Learn more.

This setting uses four markers to calculate and display 12 values.

The four markers:

The 11 displayed values:

Param

Description

Calculated from...

Pnop Out

Output power at the power normal operating point.

Marker 4 Y-axis value

Pnop In

Input power at the power normal operating point.

Marker 4 X-axis value

Pnop Gain

Gain at the power normal operating point.

Pnop Out - Pnop In

Pnop Comp

Compression at the power normal operating point.

Pnop Gain - Linear Gain*

PMax Out

Maximum output power.

Marker 3 Y-axis value

PMax In

Input power at the maximum output power.

Marker 3 X-axis value

Gain Max

Gain at the maximum output power.

PMax Out - PMax In

Comp Max

Compression at the maximum output power.

Gain Max - Linear Gain*

PBO Out

Output power at the back-off point.

Marker 2 Y-axis

PBO In

Input power at the back-off point.

Marker 2 X-axis

PBO Gain

Gain at the back-off point.

PBO Out - PBO In

*Linear Gain (not shown): Marker 1 - Y-axis value MINUS X-axis value

Search Range

Search domain settings restrict the stimulus values (X-axis for rectangular format) to a specified span. Set the User Start and User Stop stimulus settings of these User spans. If User Start is greater than User Stop, the marker will not move. Learn how to set Search Range.

 The graphic below shows examples of search domains.

 

Search Range Indicators

A search range will be indicated with a pair of small, outlined triangles sitting on the X-axis. Although there can be multiple search ranges in use on various markers, only the current-selected search range for the active marker is displayed. This rule prevents the possibility of the X-axis being cluttered with many search range triangles. This rule applies even when there are multiple traces in a window.

Only one search range will be displayed on a grid at any time. The displayed search range will correspond to the active trace and active marker. The color of the range indicators will match that of the active trace.

Range indicators will appear automatically when appropriate and cannot be disabled. The mouse or touchscreen can't be used to “click-and-drag” the position of the range indicators which will alter the search range definition.

Search Within

The zoomed frequency range becomes the User 16 Search Domain span.

A marker is created if not already present on the trace. If markers are already present on the trace, the lowest marker is moved to the found value.

  1. Left-click the mouse or use a finger, then drag across a portion of a trace.

  2. Release the mouse or lift the finger.

  3. Select Search Within.

  4. Then choose from the following:

Marker Functions - Change Instrument Settings

The following settings change the relevant analyzer  settings to the position of the active maker.

How to change Instrument settings using markers

Using Hardkey/SoftTab/Softkey

Using a mouse

  1. Press Marker > Marker->Functions.

  1. Move a cursor on a marker.

  2. Right-click on the marker and then select Functions.

  3. Select the desired search function.

  4. Click Function... to show the Marker Function Dialog box.

Marker Function dialog box help

 

Note: Marker Functions do not work with channels that are in CW or Segment Sweep mode.

Marker =>Start  Sets the start sweep setting to the value of the active marker.

Marker =>Stop  Sets the stop sweep setting to the value of the active marker.

Marker =>Center  Sets the center of the sweep to the value of the active marker.

Marker =>Ref Level  Sets the screen reference level to the value of the active marker.

Marker =>Delay  The phase slope at the active marker stimulus position is used to adjust the line length to the receiver input. This effectively flattens the phase trace around the active marker. Additional Electrical Delay  adjustments are required on devices without constant group delay over the measured frequency span. You can use this to measure the electrical length or deviation from linear phase.

This feature adds phase delay to a variation in phase versus frequency; therefore, it is only applicable for ratioed measurements. See Measurement Parameters.

Marker =>Span  Sets the sweep span to the span that is defined by the delta marker and the marker that it references. Unavailable if there is no delta marker.

Marker =>CW Freq  Sets the CW frequency to the frequency of the active marker. NOT available when the channel is in CW or Power Sweep. Use this function to first set the CW Frequency to a value that is known to be within the current calibrated range, THEN set Sweep Type to Power or CW.

Note: Some Marker Functions do not work with channels that are in certain Sweep Types.

Marker Function

Sweep Type

Lin/Log Freq.

Segment

Power

CW Time

Start, Stop, Center

S

 

S

 

Span

S

 

S

 

Ref Level

S

S

S

S

Delay

S

S

S

S

CW Freq.

S

S

 

 

S: Available in only Standard Class

 

SA Analysis Markers

The following markers are specific to Spectrum Analyzer measurement channels.

Spectrum Analysis markers

Using Hardkey/SoftTab/Softkey

Using a mouse

  1. Press Marker > SA Analysis.

  1. Click Response.

  2. Select Marker.

  3. Select the desired marker.

Band Power – Provides a readout of the total power obtained by integrating over the specified frequency range defined by Band Span, centered at the marker position.

The Average detector type makes the display more consistent with Band Power markers. With this detector type the marker readouts and the estimated power values or delta from the display have a good match. Many legacy spectrum analyzers need to set the detector type to average to do band power measurements. analyzer -SA does not need to select the average detector to compute the right band power measurements, it’s only useful to check the values between marker readouts and display estimates.

Band Density – Selections are Off, Noise, Power, Tone, NPR, or ACPR

Note: The band-density markers can be set to Delta ON mode which is very useful for NPR and ACPR, which are defined as distortion power in a specified band divided by in-band power. For these ratioed measurements, the reference marker can be set to Tone Band Density, with a Band Span that covers the in-channel bandwidth (for NPR, see Equivalent Span below to account for the reduction in channel power due to the notch). The ACPR and NPR delta markers will have a Band Span defined by the adjacent-channel bandwidth or the notch bandwidth respectively.

Band Span – Sets the frequency range over which Band Power and Band Density measurements are calculated.

Equivalent Span – Sets the frequency range over which Power and Tone Band Density measurements are normalized. This feature is useful for calculating the power density of a wideband signal with a notch (or multiple notches), where the power in the notch(es) is significant and cannot be ignored. Adjusting the Equivalent Span is essential for calculating the correct tone powers of a noise-power-ratio (NPR) signal. For example, for a 100 MHz signal with a 10 MHz notch, the Equivalent Span would be 90 MHz. For measuring the power in the notch, the Equivalent Span and Band Span are the same (10 MHz in this example).

Density BW – Sets the frequency range over which Tone Band Density measurements are calculated.

Occupied BW – Enables/disables the frequency range that contains a defined percentage of the overall band power as specified by OBW Percent.

OBW Percent – Sets the percentage used to calculate Occupied BW.

 

NPR Measurement Example

Noise-Power-Ratio (NPR) measurements are displayed using a fixed reference marker (set to Tone Band Density) that calculates the power density of the main signal, and a delta marker (set to NPR Band Density) that calculates the power density of the distortion signals within the notch. The Equivalent Span of the main signal is set to the Band Span minus the notch bandwidth – for example, for a 100 MHz wide NPR signal with a 10 MHz notch, the Equivalent Span would be 100 MHz - 10 MHz = 90 MHz. For the notch in this same example, the Equivalent Span would be set to 10 MHz.

 

Calculations for Band Power and Density Markers

All the band-power and band-density markers are computed from Discrete Fourier Transform (DFT) data, before the data is processed into the display points shown on the screen as traces. As a result, these markers are not affected by the number of display points, or by the detection algorithm used (average, sample, peak, etc.). There are two ways to access the DFT data if a user wishes to do their own calculations of power, or to perform other mathematical processing:

  1. Set the Detector Type to Bypass, which works if the number of DFT points is below 100,003 (the trace-size limit).

  2. Use the SA Data feature (accessed via the Advanced tab of the SA Setup dialog). In general, the display points do not provide an accurate representation of band-power or band-density values.

There are many more DFT data points than display points, and the data reduction performed by the detection algorithm causes band-power accuracy to degrade at signal discontinuities, where there is a wide change in power values. In addition, when using peak detection, the algorithm takes the largest power value of the DFT data-set to produce a single display point, so the displayed value does not represent the average power of the band covered for that point. For these reasons, it is impossible to compute an accurate band-power or band-density value from display points using the peak detector. This is why the SA band-power and band-density markers are computed from the underlying DFT data.

Marker Display

The marker display dialog allows you to change how markers and the associated readout is displayed on the analyzer  screen. Several marker display features also apply to Statistics display.

How to change Marker Display settings

Using Hardkey/SoftTab/Softkey

Using a mouse

  1. Press Marker > Marker Setup > Marker Display....

OR

  1. Press Display > Display Settings > Customize Display....
  2. Select Markers tab.

  1. Move a cursor to the marker data area on top right corner of grid box.

  2. Right click on the marker data display area.

  3. Select Marker Display....

OR

  1. Right click on any window area.

  2. Click Customize Display....

  3. Select Markers tab.

Customize Display dialog box help

 

The following settings apply to readouts of ALL currently-displayed marker, bandwidth, and trace statistics.

These settings revert to their defaults on Preset but ARE stored with Instrument State and User Preset.

Marker Readout

Checked - Shows readout information.

Cleared - Shows NO readout information.

Large Readout

Checked - Shows the marker readout in large font size for easy reading. However, all readout lines may not be visible.

Cleared - Shows the marker readout in normal font size.

Active Trace Only

Checked - Shows the marker readout for the active trace only.

Cleared - Shows all marker readouts.

Readouts Per Trace

Choose the quantity of marker readouts to show in the window for each trace. Choose to display up to 16 readouts per trace, up to 20 readouts per window. When more markers are present than the specified quantity of readouts, the marker numbers for which readouts are displayed can change depending on the marker number that is active. Readouts Per Trace can be set independently for each window.

Symbol

Choose from the following marker symbols.

Triangle

Flag

Line

Line symbols are NOT used on Smith or Polar display formats.

Symbols can be set independently for each window.

Symbols Above Trace

Cleared - ONLY the active marker is displayed above the trace. Inactive markers are displayed below the trace.

Checked - ALL marker symbols are displayed above the trace. The active marker is always filled solid.

Decimal Places

Choose the marker readout resolution to display. These values also apply to the readouts that are displayed in the marker table. Decimal Places can be set independently for each window.

Stimulus (X-axis)  - Choose from 2 to 6 places after the decimal point. Default is 3.

Response (Y-axis) - choose from 1 to 4 places after the decimal point. Default is 2.

Readout Position

Choose where to place the marker readouts.  Marker readouts are right-justified on the specified X-axis and Y-axis position. The default position (10.0, 10.0) is the upper-right corner of the grid. Position (1.0,1.0) is the lower-left corner. Readout position can also be set independently for each window.

Note:  Readout Position can also be changed using a mouse by left-clicking on the top readout and dragging to the new position.

Marker Colors  Starts the Display Colors dialog with only the marker colors available. Learn more.

Marker Table

You can display a table that provides a summary of marker data for the active trace. The marker data is displayed in the specified format for each marker.

How to view the Marker Table

Using Hardkey/SoftTab/Softkey

  1. Press Marker > Marker Setup > Marker Table.