RadiMation Application Note 154

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

This application note explains how the MIL-STD 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 execute this test:

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

Configuration of the test sites

Calibration

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
Reflected power meter	Devices 1	The reflected power meter to use (optionally)
Sensor power meter	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
Cable current -> power meter	Cables	Cable (1) with a correction file specified for the cable loss
Cable current -> power meter	Cables	Cable (2) with the specified loss of the used attenuator
Cable current -> power meter	Cables	Cable (3) with a correction file specified for the cable loss

Verification

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
Reflected power meter	Devices 1	The reflected power meter to use (optionally)
Sensor power meter	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
Cable current -> power meter	Cables	Cable (1) with a correction file specified for the cable loss
Cable current -> power meter	Cables	Cable (2) with the specified loss of the used attenuator
Cable current -> power meter	Cables	Cable (3) with a correction file specified for the cable loss

EUT Testing

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
Reflected power meter	Devices 1	The reflected power meter to use (optionally)
Sensor power meter	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
Cable current -> power meter	Cables	Cable (1) with a correction file specified for the cable loss
Cable current -> power meter	Cables	Cable (2) with the specified loss of the used attenuator
Cable current -> power meter	Cables	Cable (3) with a correction file specified for the cable loss

Calibration procedure

Create a correction file for the test level

    File

       New

          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 critcal) / Curve 5 are configured.

Make sure to remove the Correction column and add the Current column with the unit set to dBuV.

Create calibration test setup files

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 %

    Calibration

       System calibration

          Conducted immunity

Create three test setup files, this example shows the settings for band 1.

Start

The start frequency of the test. For example 10 kHz.

End	The stop frequency of the test. For example 1 MHz.

Step	The frequency step, in this case 5%.

Test level

The test level, in this case current.

Variable

The variable test level, select the correction file created earlier.

Tolerance

The regulation tolerance.

Calibration method

Forward power.

Test equipment

Calibration test equipment.

Test engineer

The engineer that performed the calibration.

Calibration result

When the three calibrations are performed there should be three calibration files created.

Verification

Create the Test Setup File (TSF)

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 developed current is within 3 dB tolerance of the current test limit.

    Tests

       Conducted Immunity

          Multiband

Create a new multi band 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 %

Each band needs a test level defined with the test level "Current substitution method" and the appropriate calibration file attached. Make sure to select the same "Power Method" as done during the calibration, in this case "Forward Power".

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

Start

The start frequency of the test. For example 10 kHz.

End	The stop frequency of the test. For example 1 MHz.

Frequency Step

The frequency step, see 5.12.3.4.c.3.

Dwell Time

The dwell time specified see TABLE II.

Frequency Change Mode

Constant.

Modulation

Modulation is optional during the verification.

Test equipment

The equipment needed for the verification.

Location Type

Injection clamp.

Test Level

Specify the current substitution method.

Inputs

Add the current sensor as an input.

Run the verification test

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

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 5.12.3.4.c

The sensitivity of an EUT to incoming electromagnetic interference. This is equivalent to the term Immunity. RadiMation® always uses the term Immunity.

Line Impedance Stabilisation Network

Equipment Under Test

The ability of an EUT to be immune to incoming electromagnetic interference. This is equivalent to the term susceptibility that is used by some standards.

Test Setup File

Decibel

The ability of an EUT to be immune to incoming electromagnetic interference. This is equivalent to the term susceptibility that is used by some standards.