Frequency Converter Application

FCA includes both Scalar (SMC) and Vector (VMC) measurements and calibrations.

In this topic:

See Also

Other Application topics

FCA Options Explained

Note: The VMC of the E5080A is provided by macro.

 

Scalar Mixer Calibration

Overview

Provides highest Scalar accuracy for measurements of conversion loss/gain.

Combines SOLT and power-meter calibration.

Simpler setup than Vector Mixer Calibration.

Measurements Offered

Both forward and reverse directions.

DUT can be connected to any VNA ports.

Equipment Required

Power meter and sensor

Equipment for SMC

  • Mechanical cal kit or ECal module

See Comparison of Mixer Characterization using New Vector Characterization Techniques.

Requirements and Limitations

The following VNA features are NOT available with FCA:

How to make SMC Measurements

The following is an overview of how to make an FCA measurement:

  1. DECIDE to use either a SMC measurement. See a comparison of these two measurement types.

  2. CREATE a SMC Measurement.

  3. SETUP the measurements.

  4. CALIBRATE your measurement.

Create an SMC Measurement

  1. Press Meas > Meas Overview > Measurement Class.

  2. Select SMC.

  3. The default measurement parameter is displayed.

  4. See SMC measurements to learn about the parameters that are offered in each.

How to make SMC settings

To provide quicker access, use the Setup softkey. Learn how.

Using Hardkey/SoftTab/Softkey

Using a mouse

  1. Press Freq or Sweep > Main > Mixer Setup.

  1. Right click on the stimulus range area under grid box.

  2. Click on Sweep Setup....

Valid Mixer Configuration / Sweep Type Combinations

Configuring the SMC dialog can be challenging at first.  RED messages like this one appear at the bottom of the Setup dialog to notify you of an invalid setup.

At least one range (Input, LO, or Output) MUST be Fixed.

The following are the Valid Mixer Configurations:

Sweep Type

Input

LO

Output

Linear

Swept

Swept

Fixed

Swept

Fixed

Swept

Fixed

Swept

Swept

CW Time

Power

Fixed

Fixed

Fixed

 

Tips

Although you will soon become comfortable navigating these tabs, at first it may be best to complete the dialog in the following order:

  1. For 2-stage mixers, select Mixer Setup settings.

  2. Select Sweep tab settings.

  3. Select Mixer Frequency settings.

  4. Select Power settings.

  5. Select Mixer (LO) Power settings.

 

Sweep Tab - SMC dialog box help

Sweep Type

Linear  Sweep frequency. Measurements are displayed on a standard grid with ten equal horizontal divisions.  Learn how to select the range to display on the X-Axis.

CW Time  All ranges are set to a Fixed (CW) frequency, and the data is displayed versus time.

Segment Sweep  Sweep user-defined segments. Learn more.

Power  Sweep Input or LO power.

 

X-axis Point Spacing (Available only with Segment Sweep) - Learn about this feature

    Number of Points  Learn about this feature.

    IF Bandwidth  Learn about this feature.

     

    Learn about these buttons.

     

    Power Tab - SMC dialog box help

    Note: Set LO Power on the Mixer (LO) Power tab.

     

    Configures Input and Output power settings for an FCA measurement. Use the Mixer Power tab to set LO power.

    Power ON (All channels)  Check to turn RF Power ON or clear to turn power OFF for all channels.

    Port Powers Coupled   Check to set the same power level at the DUT Input and Output ports. The LO power is NOT coupled. Clear to set power levels independently for each test port. Uncouple power, for example, to apply more power in the reverse direction than in the forward direction  Learn more about Setting Independent Port Power

    DUT Input / Output Port

    Select the VNA port that is connected to the DUT Input and Output.

    ote: In M9485A, Only ports 1 to 4 can be set even if your unit has more than 4-port configuration.

    Power Level  Set the power level to the DUT Input port. To set power at the Output port, clear the Port Powers Coupled checkbox.

    .

    DUT Input and Output Port Power Sweep

    Available when Power (sweep) is selected on the Sweep tab.

    Input Start and Stop Power  To set Start and Stop power at the Output port, clear the Port Powers Coupled checkbox.

    Power Points  Number of power points to measure.

    Power Step (Size)  Calculated value from current Start, Stop, and Points settings. This setting can NOT be changed directly.

    Path Configuration    

     

    Learn about these buttons.

    The following tabs are shared with all Mixer / Converter Applications:

    Mixer Frequency tab - SMC Setup -dialog box help

    Learn about this dialog

     

    Mixer Setup tab - SMC Setup -dialog box help

    Learn about this dialog

     

    Mixer (LO) Power tab - SMC Setup -dialog box help

    Learn about this dialog

    FCA Segment Sweep

    The following settings appear on the Mixer Frequency tab when Segment Sweep is selected on the Sweep tab.

    Mixer Frequency tab - Segment Sweep - SMC dialog box help

    How to configure a segment:

    1. Click Add. Click Delete to remove a segment and renumber all subsequent segments.

    2. State is ON by default. Click OFF and that segment will not be included in the sweep.

    3. Configure Frequency settings for Input, LO, and Output ranges.

    • For each segment, the same sweep requirements apply as a standard (non-segment) sweep. For example, at least one range MUST be Fixed (Start = Stop frequencies).

    • The Input, Output, and LO frequencies of segments ARE allowed to overlap other segments.

    • All segments must sweep in either the forward (Start<Stop) or reverse (Start>Stop) directions. Mixed sweep directions are NOT allowed.

    • The following settings can be set independently for each segment:

    Learn about these buttons

    Apply and Interpolate FCA Cal Sets

    In general, when a Cal Set covers a wider frequency range than the channel, the VNA will offer to interpolate the Cal Set when it is applied. Learn more. However, with FCA measurements the LO frequency range may also be considered.

    These same general concepts apply to segment sweeps. However, if ALL applicable frequency ranges (SMC: Input and Output ) are NOT within those ranges of the measurement for ONE segment, then the Cal Set is NOT applied for ANY segment.

    Select X-axis Display for FCA Measurements

    Click Sweep > Main > X-Axis Type, then select the desired type.

    When Sweep Type = Linear, you can choose to show the frequency range of any of the swept parameters on the X-axis.

    Save Trace Data

    You can save your FCA measurement data in several standard formats.

    Click Save Recall > Save Other > Save Data....

    The following shows how CSV and SNP files are saved.

    Mixer Trace Data

    When you select Mixer Trace Data, the FCA data is saved to a CSV file in the following format:

    #MIXER TRACE FILE,A.01.00

    SegIndex, InputFreq, OutputFreq, LO1Freq, InputPower, LO1Power, SC21 Mag (dB), SC21 Phase (Deg)

    SNP Format

    Each record contains 1 stimulus value and 4 parameters (total of 9 values) as follows:

    Stim  Real(p1)   Imag(p1)   Real(p2)   Imag(p2)   Real(p3)   Imag(p3)   Real(p4)   Imag(p4)

    where pX is the parameter depending on measurement type:

    Measurement Type

    p1

    p2

    p3

    p4

    Scalar

    S11

    SC21 (FWD)

    SC12 (REV)

    S22

    All files contain the following Header Information: Brackets [  ] contain parameters.

    !Keysight [Instrument Model Number]: [version]
    !Mixer S2P File: [Mixer Measurement Type]
    !Parameters: [Parameter List]
    !Calibration State: [On/Off]

    !# Begin Mixer Setup
    ![Mixer Setup parameters listed here]
    ![Mixer Parameter 1]
    .
    .
    ![Mixer Parameter n]
    !# End Mixer Setup

    # [S2P data here]

    Last modified:

    18-May-2016

    First releae