Noise Figure on Converters (NFX) - Opt 028, Opt 029, and Opt S9x029A/B

This topic discusses Noise Figure on Converters:

• Requirements and Limitations

• How to Configure your Hardware

• Create a NFX Measurement

• NFX Parameters

• Valid Mixer Configuration / Sweep Type Combinations

• • Frequency tab

  • Power tab

  • Noise Figure Setup tab

  • Mixer Frequency tab (separate topic)

  • Mixer Power tab (separate topic)

  • Mixer Setup tab (separate topic)

The following general information (contained in Noise Figure Application for Amplifiers) is also relevant for NFX measurements:

• Noise Figure Hardware and Software Options Explained

• Features and Requirements

• Noise Concepts

• How the Noise Figure Application Works

• Scalar Noise Figure Measurements

• Perform Calibration

• Noise Figure Measurement Tips

• Noise Model and the Noise Correlation Matrix

Other Application Topics

Requirements and Limitations

Noise Figure on Converters requires Noise Figure (Option 0pt 028 or 029 and S9x029A/B).

Learn more about Noise Figure requirements.

Limitations

• Upconverters OR downconverters ONLY (not both).

• Image rejection is NOT provided in NFX.

The following VNA features are NOT available with NFX:

• Analog Sweep (Stepped sweep mode only)

• Independent IFBW, Power Levels, or Sweep Time in a segment table is NOT supported.

• Log frequency sweeps

• ECal User Characterization

• Time Domain

• Balanced measurements

• Save Formatted Citifile data.

• Some Fixturing Features

• External Test Set Control (Option S93551A/B)

• External DC Devices

• Pulse measurements

• See Frequency Limitations

• Option 205 or Option 425

• Segmented sweeps (an alternative is to set up a separate channel for each frequency band)

Embedded LO measurements ARE supported in NFX. Learn more.

How to Configure your Hardware

The PNA-X is extremely versatile, and can be configured in many ways to make NFX measurements. While not all conceivable configurations are documented here, a few of the most common examples are provided to show the basic concepts.

DUT Configuration

Learn more about connecting the DUT input and output to the VNA.

The DUT LO can be connected to an external source OR VNA internal second source (if available).

Select an LO Source on the Mixer Setup tab.

Note: Noise that is present on the LO source will be directly transferred to the DUT output. This noise can NOT be calibrated out of the noise measurement. Therefore, choose a low-noise source for the LO, such as an Keysight ESG or PSG, which is better than the VNA internal source.

External LO Source though Port 3 or Port 4  (4-port PNA-X only)

• Connect the DUT LO to PNA-X Port 3 or Port 4.

• Connect external source to rear-panel J7 (Rear-panel load on below diagram) for Port 3; J3 for Port 4.

• • For Port 3, NO switching is required.

  • For Port 4, switch Port 4 Bypass Switch to Rear Panel.

PNA-X Internal LO Source

• SRC 2 Out 1 or Out 2 on front-panel or 2-port / 2-source PNA-X

• Port 3 or Port 4  on 4-port PNA-X

Using the Noise Figure Application

Use the following general procedure to make measurement with the Noise Figure App:

1. Connect Tuner and Noise Source.

2. Create a Noise Figure Measurement.

3. Make Noise Figure Settings.

4. For Opt 029 and H29, copy your Noise Source ENR file to the VNA C:\Program Files(x86)\Keysight\Network Analyzer\Noise folder.

5. Perform Calibration

6. Connect the DUT. Learn more.

7. Measure Noise Figure.

8. Optional  Click File, then Save to save Noise Figure data in the following formats: (available ONLY when NF correction is ON.)

   • *.CTI  Citifile

   • *.PRN  

   • *.nco  Noise Correlation Matrix data in S2P format.  See Noise Model.

See Also: Measurement Tips

Connect Noise Tuner and Noise Source

1. Connect the noise source to the 28V connector on the PNA-X rear panel. NOT required for Opt 028.  The Noise Source is turned ON and OFF automatically as needed during a calibration. Connect the noise tuner to Port 2 reference place when prompted during calibration.

2. Connect the noise tuner (ECal module). NOT required for 50 GHz models and  Scalar Noise Figure measurements.

   1. On the VNA front panel, remove the Port 1 jumper cable SOURCE OUT / CPLR THRU. Opt 028 allows Noise Figure measurements using any two VNA ports. Connect the noise tuner to the front-panel jumpers for the source (DUT input) port.

   2. Connect M-F tuner (N4691B-M0F) using the supplied cable (N5242-20137) and adapter (85052-60013).

   3. When using F-F ECal module (N4691B-00F), order a 3.5 mm M-M adapter (85052-60014).

Create a Noise Figure Measurement

1. On the VNA front panel, press Meas > S-Param > Meas Class....

2. Select Noise Figure Converters, then either:

   • OK delete the existing measurement, or

   • New Channel to create the measurement in a new channel.

3. A Noise Figure measurement is displayed. Do the following to add or change parameters to display.

NFX Parameters

The same Noise parameters that are available in the Noise Figure application are also available in the NFX application. Learn more.

In addition, the following Mixer and Raw Receiver parameters are available in an NFx channel:

Mixer Parameters

• SC21- Conversion Loss

• SC12 - Reverse Conversion Loss

• S11 - Input match

• S22 - Output match

• IPWR - Input power to mixer/converter. Same as R1 (Source1)

• OPWR - Output power to mixer/converter. Same as B (Source1)

• RevIPWR - Power applied to mixer/converter Output. Same as R2 (Source2)

• RevOPWR - Power measured at mixer/converter Input. Same as A (Source2)

Raw Receiver Parameters

Specify a receiver to measure at LO1 frequencies with the notation:

• <Receiver>LO1

• For example: ALO1 or R1LO1

Specify a receiver to measure using a source port, with the notation:

• <Receiver>_<source port>

• For example: A_3 or R1_1

Valid Mixer Configuration / Sweep Type Combinations

The following are the Valid Mixer Configurations:

For determining a valid mixer configuration with 2 LOs, one Fixed LO and one Swept is equivalent to having a single-stage Swept LO.

If you create an invalid Sweep Type / Mixer Configuration, a red message appears like the following:

If this occurs, change the Sweep Type on the Frequency tab.

See other rules for configuring a mixer.

The following tabs are available on the NFX Setup dialog:

• Frequency

• Power

• Noise Figure Setup

• Mixer Frequency (separate topic)

• Mixer Power (separate topic)

• Mixer Setup (separate topic)