Vector Signal Analyzer (VSA - Option 095)

Configure VSA settings

Using Hardkey/SoftTab/Softkey

Using a mouse

1. Press Freq > Main > VSA Setup....

1. Click Stimulus

2. Select VSA Setup

VSA Setup Dialog tab help

Frequency (See Example configurations)

Sets the SA (receiver) frequency range. Use either of the following pairs of settings to determine the frequency range.

Start /Stop - Specifies the beginning and end frequency of the swept receiver range. Start is the beginning of the X-axis and Stop is the end of the X-axis. When the Start and Stop frequencies are entered, then the X-axis annotation on the screen shows the Start and Stop frequencies.

Center /Span - Specifies the value at the center and frequency range. The Center frequency is at the exact center of the X-axis. The Frequency Span places half of the frequency range on either side of center. When the Center and Frequency Span values are entered, then the X-axis annotation on the screen shows the Center and Span frequencies.

CF Step Size - Manually sets the amount Center frequency change that occurs when ▲|▼ is clicked (next to the value).

Auto - Each press of the ▲|▼ arrows increments or decrements the Center frequency by 5% of the current frequency span.

Receiver Attenuator

Receiver Attenuation is used to protect the test port receivers from damage or compression. Receiver attenuation causes the reported power at the receiver to be less than the power at the test port by the specified amount of attenuation.

Receiver Attenuators are offered as an option. Learn more.

Type or select independent attenuation values for each test port receiver.

A preference can be set to mathematically offset (or NOT) the reported power at the test port receivers by the amount of receiver attenuation. By default, All PNA/PNA-X models offset the display. Learn how to set the preference.

Connect VSA

Check to launch the VSA software for further signal evaluation.

IF Dialog tab help

IF Gain

Auto - Selects the appropriate amount for gain versus RF frequency bands for each receiver IF Path.

Or select a specific amount of gain (in dB) for IF receiver paths.

Couple all IF paths - When checked, all receivers assume the same setting. When cleared, each receiver can assume an individual setting.

IF Config - Accesses the IF Path Configuration dialog. Learn all about IF Path Configuration.

ADC Filter - Selects between a narrow and wide IF filter anti-aliasing path.

Narrow 11MHz - Selects the ADC 11 MHz IF filter path. A warning message will appear if the Narrow IF filter path is selected and the Resolution Bandwidth is > 1 MHz.

Wide 38MHz - Selects the ADC 38 MHz IF filter path.

ADC Sampling Frequency - Select between 100 MHz and 25 MHz.

ADC Dithering - Check to allow ADC dithering to average out the characteristic "stair steps" produced during the ADC conversion process.

Advanced Settings Dialog tab help

LO Side

Low- Selects the low LO side: LO Freq = VSA Center - IF Offset.

High - Selects the high LO side:  LO Freq = VSA Center + IF Offset.

IF Offset - Sets the IF offset.

ADC Stacking - Stack ADC samples by the specified number (≥1) and store result in memory. For example, if an ADC record size of 1,000 samples is acquired and ADC Stacking is set to 1, then 1,000 samples will be added to 1,000 samples and the result (1,000 samples) will be stored in memory. Stacking helps to reduce noise and increase dynamic range. However, this feature should only be used when the source frequency is coherent with the current ADC record size. A value of 0 means no stacking.

If the ADC stacking range is set over the limit, an error message appears and the value will be changed to the upper limit value automatically.

Stream data to file - Check to allow saving of FFT data and raw ADC data to disk. Data files are stored in C:\Users\Public\Documents\Network Analyzer\VSALink. For each measurement sweep and each trace, two .csv files are stored. The preferred method is to use single sweep mode.

The filenames are in the following format.

FFT_CH_1_Rcvr_B.csv

IFFT_CH_1_Rcvr_B.csv

The numbers/letters in red are dependent on the current channel number and which test receiver is measuring the trace. For example, if traces A, B, and R1 are being measured on channel 1, then 6 files are created after a single sweep:

FFT_CH_1_Rcvr_A.csv
IFFT_CH_1_Rcvr_A.csv
FFT_CH_1_Rcvr_B.csv
IFFT_CH_1_Rcvr_B.csv
FFT_CH_1_Rcvr_R1.csv
IFFT_CH_1_Rcvr_R1.csv

The filenames are automatically defined by firmware.

Source Setup tab help

Power On (All Channels)  Check to enable source power for all channels. Only turns power ON if the port State setting is ON.

Source Cells

Name - Lists the test ports through which an internal source is available. If an external source has been configured, it will appear at the bottom of the list.

State

• ON  Source power is ALWAYS ON. Turning ON port 1 will also turn ON port 2 and vice versa. The same is true for port 3 and port 4. Learn about internal second source restrictions.

• OFF  Source power is never ON, regardless of the measurement requirements. Use this setting to prevent damage to a sensitive DUT test port.

• No Control  Available ONLY on external sources. The VSA application will NOT control the external source.

Type (Sweep)

CW - The source is set to a CW frequency.

Linear - The source is set to sweep from the Start to Stop frequency.

Frequency - Click in the cell, then click Edit, to start the Frequency Settings dialog (below).

Power - Sets the power level at the output of the source.

Modulation - Choose from OFF, ON, Pulse.

Buttons

Path Configuration

The configuration above shows a 4-port PNA-X with option 423 installed (combiner and mechanical switches).

If configuring an external modulation source, select the Combiner Path in the Port 1 Bypass Switch. Learn more

Pulse Setup  Learn more

External Devices

1. Enter a name for your source in the Name field.
2. For Device Type, select Source.
3. For Driver, select the source (MXG or EXG).
4. Select the Interface that is used to connect the device to the PNA/PNA-X.
5. From the Available list, select the device that is connected to the specified IO Interface.
6. Check Active - Show in UI and Enable IO.

For more information about configuring an external device, see Configure an External Device.

Power and Attenuator  Learn more

(Source) Frequency Settings dialog help

In the Source Setup Tab (above):

> When (Sweep) Type = CW, set the CW Frequency.

> When (Sweep) Type = Linear, the following dialog appears:

Settings

Sets the source frequency range. Use either of the following pairs of settings to set the frequency range.

Start /Stop - Specifies the beginning and end frequency of the swept range.

Center /Span - Specifies the value at the center and frequency range.

Source Number of Steps - Sets the number of steps the source will make across the specified source frequency range.

SA Sweeps / Source Step - Sets the number of SA (receiver) sweeps for each Source Step. This setting is common to all sources.

How to select and configure Measurement Parameters

Using Hardkey/SoftTab/Softkey

Using a mouse

1. Press Trace, then select trace.

2. Press Meas, then select a parameter.

1. Click Instrument, Trace, Add Trace.

2. Click Response, Meas, then select a parameter.

Measure dialog help

Select one of the test port receivers to make a measurement. Test ports are identified in both traditional PNA/PNA-X notation and Receiver Notation. Learn more.

Create in New Window - When checked, the selected measurements are created in a new window.

Connect to VSA

Using the VSA Toolbar

Using Hardkey/SoftTab/Softkey

Using a mouse

1. Press Freq > Main >  VSA Setup....

2. Check Connect VSA

1. Click Stimulus

2. Select VSA Setup...

3. Check Connect VSA

VSA Toolbar

The VSA toolbar is located in the upper-left part of the PNA/PNA-X interface.

Connect VSA -  Launches the 89600 VSA interface. The PNA/PNA-X channel must be running the VSA application to connect to the 89600 VSA interface.

Minimize - Minimizes the PNA/PNA-X interface.

Show VSA - Displays the 89600 VSA interface and minimizes the PNA/PNA-X interface.

X - Closes the VSA toolbar. To open the toolbar again, select Response, Display, Toolbars, then VSA.

PNA/PNA-X Measurement Channel to VSA Physical Channel Mapping

The 89600 VSA application supports up to ten VSA stream channels for a 4-port PNA/PNA-X or eight VSA stream channels for a 2-port PNA/PNA-X. These channels are mapped to a maximum of two PNA/PNA-X measurement channels running the VSA application. The VSA stream channels are divided into two groups called CHA and CHB. The suffix (for example, "R" in R_CHA) corresponds to an active PNA/PNA-X receiver.

When the PNA/PNA-X channel connects to the 89600 VSA, one of the VSA stream channel groups is assigned to the PNA/PNA-X channel if available and a new VSA measurement is created. VSA measurements are configured as synchronous measurements.

Viewing Channel Mapping

By hovering over the trace window tab shown below (for example, A:Ch1 Spectrum), the mapping assigned to this window is displayed.

Measurement - Displays the PNA/PNA-X channel number (PNA_CH1 or PNA_CH2).

Measurement Channel - Displays the VSA measurement channel for the active measurement. For example, Ch1 corresponds to the first channel of this particular VSA measurement.

Logical Channel - Displays the interface between the physical channel hardware ports and the measurement channels.

Physical Channel - Displays the PNA/PNA-X receiver/VSA stream channel (x_CHA and x_CHB where "x" is the reference or test receiver).

DataName - Displays the name of the window.

Verifying Mapping with the Channel Configuration Dialog

In the 89600 VSA interface select Input, Channels, then Custom to view the Channel Configuration dialog which shows the current mapping between the PNA/PNA-X measurement channels and the VSA physical channels.

The following graphic is an example of a channel configuration for a 4-port VNA and ten VSA stream channels:

Note: For more information, refer to the 89600 VSA online help.

Mapping a Measurement Channel to a VSA Trace Window

Change the mapping of a displayed trace window by selecting the down arrow (or right-clicking) on the trace window tab, selecting the measurement channel, then selecting from the list of available channel trace data for this channel as shown below.

Note: Trace data selections vary with instrument configuration and measurement type. For more information, refer to the 89600 VSA online help.

By hovering over the B:Ch2 Spectrum trace window tab shown below, the new mapping assigned to this window is displayed.

Drag and Drop to Change Connections Using the Channel Configuration Dialog

To customize the mapping, select Input, Channels, then Custom to view the Channel Configuration dialog then "drag and drop" to move connections as shown below.

Error Message

If two PNA/PNA-X channels are currently connected and you attempt to connect a third PNA/PNA-X channel, the following error message is displayed and the third channel will not be connected:

89600 VSA Graph Trace Configuration

There are several graphs that can be selected in the 89600 VSA for each trace window. Configure the graphs using the X-Y Graph dialog accessed by selecting Trace then Graph Settings as shown below.

The dialog below is displayed and is used to configure stimulus-response measurements for the active trace. These settings only apply to graph traces.

Graph Settings Tab

Trace x - Select the trace to apply the settings.

- Adds/deletes a trace.

Visible - Check to make the trace visible.

Copy To... - Copy these settings to multiple traces.

Auto - Check to have the 89600 VSA choose a valid stimulus and response automatically.

Stimulus Data - Selects the measurement channel corresponding to the stimulus (x-axis) time data to use in the graph trace.

Response Data - Selects the measurement channel corresponding to the response (y-axis) time data to use in the graph trace.

Compensation - Check to perform amplitude normalization, time alignment, and phase error compensation before calculating the points for a graph trace. After compensation, a polynomial curve is fitted to the data if Polynomial is checked.

Time Reference - Determines whether the time axis of the graph trace corresponds to other graph traces or to the original data before compensation.

Draw As - Specifies how to draw the points in the active trace. This parameter only applies to graph traces.

Graph Results Tab

The Graph Results tab shows information about the graph calculation for the active trace.

Refresh - Refreshes summary results from trace.

Copy to clipboard - Copies summary results to clipboard.

Copy to register - Copy polynomial trace to data register.

Selecting a Graph

Selecting the down arrow (or right-clicking) on the trace window tab as shown below accesses the various graphs for the active trace. The graph selection below would select an AM/PM graph specific to trace "C".

The results below show a typical AM/PM graph.

Note: For more information, refer to the 89600 VSA online help.

Switching Between PNA/PNA-X and 89600 VSA

There are several methods that can be used to switch between the PNA/PNA-X interface and the 89600 VSA interface.

Windows Taskbar

In the Windows Taskbar, click on the PNA/PNA-X or 89600 VSA icon.

VSA Toolbar

While viewing the PNA/PNA-X interface, click on the Show VSA button in the VSA toolbar.

Alt-Tab

Using an external computer keyboard, press and hold the Alt key and press the Tab key to switch between applications.

External Monitor

With an external monitor connected to the PNA/PNA-X, view the PNA/PNA-X interface on the PNA/PNA-X display and the 89600 VSA interface on the external monitor.