Select displays the DUT S-PARAM DATA dialog box. Once opened, navigate to the location of the stored DUT S-Parameter Data SnP file type. Once found, select the Open button to retrieve the file. The S-Parameter data file must be stored and available before starting noise figure measurements.
Select displays the DUT S-PARAM DATA dialog box. Once opened, navigate to the location of the stored DUT S-Parameter Data SnP file type. Once found, select the Open button to retrieve the file. The S-Parameter data file must be stored and available before starting noise figure measurements.
NF Receiver Calibration
Select displays the NF RECEIVER CAL menu.
NF Noise Calibration
Select displays the NF NOISE CAL menu.
Noise Calibration Method (Only available for 4-Port DUTs)
Select displays the DIFF. NF METHODS menu. Choose between UNCORRELATED, CORRELATED, and OUTPUT COMBINER.
In the 4-port DUT configuration case, there are three methods for analyzing differential (and common-mode) noise figure: uncorrelated, correlated and output combiner. More details are in the Calibration and Measurement Guide but, briefly,
• Uncorrelated: Ignores correlation between noise waveforms from the DUT outputs. Differential and common-mode noise powers will be equal.
• Correlated: Uses direct correlation between VNA receivers to measure correlation directly. In this method there is also a choice if the DUT output mode is dominantly differential or common-mode. This is used to help in cases where there is a sign ambiguity (narrow sweep widths).
• Output combiner: Assumes the use of a balun/combiner at the DUT output and the .s3p file for the combiner is available. This uses single-ended noise measurements of both DUT outputs and the combined measurement to compute DUT differential noise figure.
1. NF CONFIG menu – Related button field toolbars shown to the right.
2. Start Frequency field toolbar.
3. Stop Frequency field toolbar.
4. # (Number) of Points field toolbar.
5. CW Frequency field toolbar.
6. # of RMS Points field toolbar.
7. IFBW (Intermediate Frequency Bandwidth) Frequency field toolbar – Do not change the IFBW setting after calibration.
8. Temperature K – Read-only display field button.
Start
Select displays the Start frequency field toolbar to provide input for the start frequency in GHz, MHz, kHz, or Hz.
Stop
Select displays the Stop frequency field toolbar to provide input for the stop frequency in GHz, MHz, kHz, or Hz.
# of Points
Number of Points. Select displays the # of Points field toolbar to provide input for the number of sweep points.
CW
Continuous Wave Frequency. Select displays the CW field toolbar to provide input for the CW frequency in GHz, MHz, kHz, or Hz.
# RMS Points
Number of Root Mean Square Points. Select displays the # RMS Points field toolbar to provide input for the number of RMS measurement points per sweep point set above. For example, if the sweep points are set to 51, and the RMS points are set to 3,000, the total measurement points are 51 × 3,000 = 153,000.
IFBW
Intermediate Frequency Bandwidth. Select displays the IFBW field toolbar to provide input for the IFBW frequency in MHz, kHz, or Hz.
Note
Do not change the IFBW setting after calibration.
Temperature K
Temperature Kelvin. Read-only display of the IEEE default temperature of 290 K. For reference:
1. Receiver Channel:NF RECEIVER menu shows and allows setting of the receiver channel for 2-port VNA or displays receiver channels for 4-port VNA.
2. Inter/Extrapolation: Calibration Interpolation and Extrapolation Mode. Read-only display. This display indicates that the VNA calibration interpolation and extrapolation mode is ON.
3. Gain Type: Toggles between INSERTION and AVAILABLE. The default (Insertion) ignores DUT match effects (can be less accurate but is commonly used). Available gain includes the effects of DUT output match.
4. Receiver Cal Offset: Opens NF RCVR CAL OFFSET menu.
1. Receiver Cal Offset: Read-only field display and toggle. Shows the Receiver Cal Offset status. After loading the receiver cal offset file (.txt), this field becomes an ON|OFF toggle for the Receiver Cal Offset function.
2. Recall Receiver Cal Offset: Opens RECEIVER CALIBRATION OFFSET dialog box. After loading the receiver cal offset file (.txt), a CheckBox (as checked) will be shown to indicate the successful file load. Also, the menu item for “Cal Offset” will be enabled and the status will be changed to ON.
NF ADVANCED Menu – 4-port DUT
1. Receiver Cal Offset: Read-only field display and toggle. Shows the Receiver Cal Offset status. After loading the receiver cal offset file (.txt), this field becomes an ON|OFF toggle for the Receiver Cal Offset function.
2. Recall VNABx Cal Offset: Opens RECEIVER CALIBRATION OFFSET Data dialog box. After loading the receiver cal offset file (.txt), a CheckBox (as checked) will be shown to indicate the successful file load. Also, the menu item for “Cal Offset” will be enabled and the status will be changed to ON.
NF ADVANCED Menu – NW Extraction Embed/De-embed
Full Name
Network Extraction embed/De-embed
Prerequisites
• Option 48 is installed on the VNA.
• The non-compressed DUT S-Parameter Data file has been stored and is available on the VNA with the filename extension .snp or .txt.
• The APPLICATION menu mode is set to Noise Figure mode.
The S-parameters to be de-embedded are sourced from .sNp files. For a 2-port DUT and N>2, the path within the file that is to be used must be specified.
For a 4-port DUT, either two .s2p files (one for the b1 and b2 receiver paths) must be specified, or a higher-count file can be used (in which case, the path belonging to the b1 receiver path must be specified and the disjoint path will be used for the b2 receiver path).
• The non-compressed DUT S-Parameter Data .sNp (N=3 or 4 for 4-port DUT selections) or .txt (for frequency converting DUTs).
• The APPLICATION menu mode is set to Noise Figure mode.
• The DUT Configuration is set to 4 Port.
Navigation
• MAIN | Application | APPLICATION | Mode = Noise Figure | Noise Figure Setup |DIFF. NF SETUP DUT Configuration = 4 PORT | Get DUT S-Param Data
DIFFERENTIAL NF DUT Data Menu – 4-port DUT
For a 4-port DUT, a ,s3p, .s4p or .txt file can be used. The .txt format is that of the MS464XX .txt save process and assumes the gain path is in trace 1. The Reassign Ports tool is used to reconfigure a file if the ports used therein do not match what the system expects (1->2 and 1->3 as the gain paths for .s3p and 1->3 and 2->4 as the gain paths for .s4p).
DIFFERENTIAL NF DUT Data Dialog Box – 2-port DUT
The DUT S-parameters/gain information for a 2-port DUT can either be entered as a .s2p file (S21 is assumed to be the gain direction) or as a .txt file (the format of the MS464XX .txt file save process). The .txt file is used for frequency conversion devices, and it is assumed the gain variable is in trace 1.
• The non-compressed DUT S-Parameter Data .sNp or .txt file has been stored and is available on the VNA.
• The APPLICATION menu mode is set to Noise Figure mode.
Navigation
• MAIN | Application | APPLICATION | Mode = Noise Figure | Noise Figure Setup |DIFF. NF SETUP DUT Configuration = 2 PORT | Receiver Cal
NF Receiver Cal Menu – 2-port DUT
An existing receiver cal for the b2 path can be recalled (2, 3) or one can be performed now (1). Either way, it is expected that port 1 (power cal at the end of that cable optional) is connected to the input of the composite receiver with a drive level low enough to avoid compression of the composite receiver.
• MAIN | Application | APPLICATION | Mode = Noise Figure | Noise Figure Setup |DIFF. NF SETUP DUT Configuration = 4 PORT | Receiver Cal
NF Receiver Cal Menu – 4-port DUT
An existing receiver cal for the b1 path can be recalled (2,3) or one can be performed now (1). Either way, it is expected that port 1 (power cal at the end of that cable optional) is connected to the input of the composite receiver with a drive level low enough to avoid compression of the composite receiver.
• The non-compressed DUT S-Parameter Data .sNp or .txt file has been stored and is available on the VNA.
• The APPLICATION menu mode is set to Noise Figure mode.
Navigation
• MAIN | Application | APPLICATION | Mode = Noise Figure | Noise Figure Setup |DIFF. NF SETUP DUT Configuration = 2 PORT | Noise Cal
NF Noise Cal Menu – 2-port DUT
This corrects for noise power from the composite receiver on b2. Connect a termination to the input of the composite receiver and press Perform VNA B2 Cal.
• MAIN | Application | APPLICATION | Mode = Noise Figure | Noise Figure Setup |DIFF. NF SETUP | DUT Configuration = 4 PORT | Noise Cal
NF Noise Cal Menu – 4-port DUT, Correlated or Uncorrelated Noise Cal Methods
This corrects for noise power from the composite receivers. Connect a termination to the input of the composite receiver and press the appropriate Perform VNA Bn Cal button.
In the uncorrelated or correlated method,
1. Select displays the NF NOISE CALIBRATION menu. Select Perform VNA Bn Cal, which opens the NOISE CALIBRATION (VNA Bn) dialog box. Once open, follow the procedure below to calibrate the noise:
2. Connect the termination to the preamplifier at the reference plane of the noise figure measurement. The dialog box figure shows the placement of the required components.
3. Select the Start Noise Cal button on the dialog box to start the calibration.
NF Noise Cal Menu – 4-port DUT, Single Combiner Measurement
NF Noise Cal Menu – 4-port DUT, Single Combiner Measurement
In the 'single' combiner method, three calibration-like steps are required:
1. Perform the noise cal on both b1 and b2 receiver paths, as with the other methods for 4-port DUTs.
2. Load .s3p data for the combiner (port 3 is assumed to be the combined port)
3. Collect single-ended noise power data for the DUT (combiner not present).
NF Noise Cal Menu – 4-port DUT, Double Combiner Measurement
NF Noise Cal Menu – 4-port DUT, Double Combiner Measurement
In the 'double' combiner method, four calibration-like steps are required:
1. Perform the noise cal on both b1 and b2 receiver paths as with the other methods for 4-port DUTs.
2. Load .s3p data for the combiner (port 3 is assumed to be the combined port).
3. Collect single-ended noise power data for the DUT (combiner not present).
4. Collect combined noise power data in the swapped configuration (i.e., the interconnects between the DUT and combiner are swapped).
NF Noise Cal Menu – 4-port DUT, Get Combiner s3p Data Dialog Boxes
NF Noise Cal Menu – 4-port DUT, Get Combiner s3p Data Dialog Boxes
When loading the combiner .s3p data file, it is expected that port 3 represents the common port. If this was not the case when the .s3p data was acquired, use the 're-assign ports' dialog to remap the ports.
