RadiMation Application Note 154

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How to perform a MIL-STD-461 CS114, Conducted susceptibility, bulk cable injection test

This application note explains how the MIL-STD-461 CS114, Conducted susceptibility, bulk cable injection test can be performed with RadiMation®

The exact requirements and test methods for the CS114 are specified in the MIL-STD-461.

Necessary equipment

The following devices are necessary to run the calibration, verification and EUT test:

  • Signal generator
  • Amplifier
  • Coupler
  • Forward power meter
  • Current sensor
  • Sensor power meter / Analyser
  • 50 Ohm load
  • 50 Ohm attenuator
  • Current injection device
  • Current injection calibration jig (Calibration fixture)
  • Cable drivers with corrections

Tips

Information.png
Note: If the current unit is shown as uA, it can be changed to dBuA by clicking Units, select Current and click Edit to change this.

Define the test level

Create a correction file for the test level

   Menu.png File
      Menu.png New
         Menu.png Correction

First create a correction file in RadiMation® and specify the applicable test level (See 'TABLE IV CS114 limit curves.' and 'FIGURE CS114-1. CS114 calibration limits.'). In this example the limits for 'Aircraft (External or safety critical) / Curve 5 are configured.

Ensure that the correction file has a Frequency column and a Current column with the unit set to dBuA.

CS114 Test level.png


   Menu.png File
      Menu.png Save correction

Store the test level as correction file on disk.

This correction file with the test level will be used during the calibration, verification and the EUT testing.

Calibration procedure

Calibration equipment

CS114 Calibration.png

The configuration of the calibration test site should contain the following devices:

# Device name Tab in testsite configuration window note
Signal Generator Devices 1 The signal generator to use
Amplifier Devices 1 The amplifier to use
Coupler Devices 1 The coupler to use
Forward power meter Devices 1 The forward power meter to use
Sensor powermeter Devices 2 The power meter or analyser to use for measuring the current
Current Sensor Devices 2 The current sensor to use with transfer factor attached to the driver
Injection device Devices 2 The injection clamp to use
Jig Devices 2 The jig to use
Cables
① Cable current -> power meter Cables Cable (1) with a correction file specified for the cable loss
② Cable current -> power meter Cables Cable (2) with the specified loss of the used attenuator
③ Cable current -> power meter Cables Cable (3) with a correction file specified for the cable loss

Configure the calibration

There are three frequency ranges that have to be calibrated with the following settings (see TABLE III).

Band Frequency range Step size
Band 1 10 kHz - 1 MHz 5 %
Band 2 1 MHz - 30 MHz 1 %
Band 2 30 MHz - 200 MHz 0.5 %

These three bands can be configured and performed in three different calibrations. The calibration can be started from the menu by selecting:

   Menu.png Calibration
      Menu.png System calibration
         Menu.png Conducted immunity

This example shows the settings for band 1.

CS114 Calibration band 1.png

ScreenElementDescription.png Start The start frequency of the test. For example 10 kHz.
ScreenElementDescription.png End The stop frequency of the test. For example 1 MHz.
ScreenElementDescription.png Step The frequency step, in this case 5%.
ScreenElementDescription.png Test level The test level, in this case current.
ScreenElementDescription.png Variable The variable test level, select the correction file created earlier.
ScreenElementDescription.png Tolerance The regulation tolerance.
ScreenElementDescription.png Calibration method Forward power.
ScreenElementDescription.png Test equipment Calibration test equipment.
ScreenElementDescription.png Test engineer The engineer that performed the calibration.


Calibration result

When the calibration is performed, the engineer is asked, to save the results of that calibration to a calibration (.CAL) file. It is possible to give the .CAL file any clear and distinct name. All three bands have to calibrated, and at the end, there should be three different calibration files that are generated.

Verification

Verification equipment

CS114 Verification.png

The configuration of the verification test site should contain the following devices:

# Device name Tab in testsite configuration window note
Signal Generator Devices 1 The signal generator to use
Amplifier Devices 1 The amplifier to use
Coupler Devices 1 The coupler to use
Forward power meter Devices 1 The forward power meter to use
Sensor powermeter Devices 2 The power meter or analyser to use for measuring the current
Current Sensor Devices 2 The current sensor to use with transfer factor attached to the driver
Injection device Devices 2 The injection clamp to use
Cables
① Cable current -> power meter Cables Cable (1) with a correction file specified for the cable loss
② Cable current -> power meter Cables Cable (2) with the specified loss of the used attenuator
③ Cable current -> power meter Cables Cable (3) with a correction file specified for the cable loss

Configure the verification

CS114 requires to perform a verification of the setup with the probes in the calibration setup. With this verification it is important to verify that the forward power of the calibration is followed and that the generated current is within 3 dB tolerance of the current test limit. The verification can be performed in RadiMation® by doing an actual conducted immunity test. This test can be started by selecting from the menu:

   Menu.png Tests
      Menu.png Conducted Immunity
         Menu.png Multiband

Create a new multiband conducted immunity test and define three bands with the following settings:

Band Frequency range Step size
Band 1 10 kHz - 1 MHz 10 %
Band 2 1 MHz - 30 MHz 2 %
Band 2 30 MHz - 200 MHz 1 %

CS114 Verification Setup.png

ScreenElementDescription.png Start The start frequency of the test. For example 10 kHz.
ScreenElementDescription.png End The stop frequency of the test. For example 1 MHz.
ScreenElementDescription.png Frequency Step The frequency step, see 5.12.3.4.c.3.
ScreenElementDescription.png Dwell Time The dwell time specified see TABLE II.
ScreenElementDescription.png Frequency Change Mode Constant.
ScreenElementDescription.png Modulation Modulation is optional during the verification.
ScreenElementDescription.png Test equipment The equipment needed for the verification.
ScreenElementDescription.png Location Type Injection clamp.
ScreenElementDescription.png Test Level Specify the current substitution method.
ScreenElementDescription.png Inputs Add the current sensor as an input.


Each band needs a test level defined with the test level Current substitution method and the appropriate calibration file attached.

CS114 Current Testlevel Configuration.png

ScreenElementDescription.png Description The description of the test level.
ScreenElementDescription.png Calibration file Select the calibration file to use.
ScreenElementDescription.png Test level Variable current, and specify the correction file for the applicable test level.
ScreenElementDescription.png Calibration method Select Forward Power.
ScreenElementDescription.png Tolerance Specify the tolerance to use.


Next to the test level add an input Current sensor, this will ensure that the current is measured during the test.

Run the verification test

When all settings are configured press Start Test to run the verification test.

CS114 Verification Result.png

Verification result

With the result of the verification it should be possible to determine if the measured current is within the 3 dB tolerance of the current test limit as specified in clause 5.12.3.4.c of the MIL-STD-461.

EUT Testing

EUT Testing equipment

CS114 EUT Testing.png

The configuration of the eut test site should contain the following devices:

# Device name Tab in testsite configuration window note
Signal Generator Devices 1 The signal generator to use
Amplifier Devices 1 The amplifier to use
Coupler Devices 1 The coupler to use
Forward power meter Devices 1 The forward power meter to use
Sensor powermeter Devices 2 The power meter or analyser to use for measuring the current
Current Sensor Devices 2 The current sensor to use with transfer factor attached to the driver
Injection device Devices 2 The injection clamp to use
Cables
① Cable current -> power meter Cables Cable (1) with a correction file specified for the cable loss
② Cable current -> power meter Cables Cable (2) with the specified loss of the used attenuator
③ Cable current -> power meter Cables Cable (3) with a correction file specified for the cable loss

Configure the EUT test

To perform the actual test on the EUT, create a conducted immunity multiband test with 3 bands. The conducted immunity multiband test, can be started by selecting from the menu:

   Menu.png Tests
      Menu.png Conducted Immunity
         Menu.png Multiband

The following bands should be configured.

Band Frequency range Step size
Band 1 10 kHz - 1 MHz 5 %
Band 2 1 MHz - 30 MHz 1 %
Band 2 30 MHz - 200 MHz 0.5 %

CS114 Test Setup.png

ScreenElementDescription.png Start The start frequency of the test. For example 10 kHz.
ScreenElementDescription.png End The stop frequency of the test. For example 1 MHz.
ScreenElementDescription.png Frequency Step The frequency step, see Table III.
ScreenElementDescription.png Dwell Time The dwell time.
ScreenElementDescription.png Frequency Change Mode Constant.
ScreenElementDescription.png Modulation Configure Pulse Modulation with 1 kHz and 50% duty cycle.
ScreenElementDescription.png Test equipment The equipment needed for the conducted immunity test.
ScreenElementDescription.png Location Type Injection clamp.
ScreenElementDescription.png Test Level Specify the current substitution method. Also add a "Measured Current Limit"
ScreenElementDescription.png Inputs No inputs are needed.


To configure the pulse modulation settings click Config next to the modulation settings, click the PM tab, and enter the pulse modulation settings as defined in 5.12.3.4.d.1. CS114 Modulation settings.png

ScreenElementDescription.png Activate modulation Check this checkbox to enable the pulse modulation.
ScreenElementDescription.png Frequency The PM frequency 1 kHz.
ScreenElementDescription.png Duty Cycle A duty cycle of 50%.
ScreenElementDescription.png Also apply modulation out of the dwell-time period Check this checkbox to enable modulation outside the dwell-time.


At TestLevel click Add to add a new Test level and select TestLevel - Current substitution method

CS114 Current Testlevel Configuration.png

ScreenElementDescription.png Description The description of the test level.
ScreenElementDescription.png Calibration file Select the calibration file to use for this band.
ScreenElementDescription.png Test level Variable current, and specify the correction file for the applicable test level.
ScreenElementDescription.png Calibration method Select Forward Power.
ScreenElementDescription.png Tolerance Specify the tolerance to use.


Next to the test level add a limit, At TestLevel click Add to add a new Limit and select Limit - Measured Current Limit

With this limit the level will not be regulated higher than the measured current in the cable even if the forward power is not reached yet.

CS114 Current limit.png

ScreenElementDescription.png Description The description of the limit
ScreenElementDescription.png Constant current The current to limit on.


When all bands are configured press Start Test to run the EUT test.

EUT Test Result

Once the test is finished, the results of this test are stored in the EUT file and available as one of the performed Tests in the EUT file. Selecting the corresponding test result and pressing on Info will show the test results again.

CS114 Test Result.png

Conclusion

The RadiMation® Conducted Immunity multiband test can be used to perform the CS114 verification and the EUT test with a calibration file and the current sensor used as a limit in the EUT test.

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