RadiMation Application Note 165

How to perform an IEC 61000-4-6, Conducted immunity test

This application note explains how the IEC 61000-4-6 conducted immunity test can be performed with RadiMation^®. The IEC 61000-4-6 conducted immunity test method is used for electrical and electronic equipment that may be subjected to radio-frequency disturbances conducted along cables coming from radio transmitters in the frequency range from 150 kHz up to 80 MHz. The exact requirements, calibration and EUT test methods are described in the IEC 61000-4-6 standard.

Necessary equipment

• Signal generator
• Amplifier
• Coupler
• Forward power meter
• Injection device
• Calibration jig with 100 Ohm resistors
• 50 Ohm load
• Attenuator in front of sensor power meter (optional)
• Sensor power meter

Calibration procedure

The calibration is performed to determine the power required to match the corresponding voltage test level seen at the output of the injection device.

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	Coupler
	Forward power meter	Devices 1	Forward power meter
	Injection device	Devices 2	The injection clamp or CDN
	Calibration Jig	Devices 2	The calibration jig to use
	Sensor power meter	Devices 2	Power meter
Cables
①	Cable current -> power meter	Cables	Cable with the specified loss of the used attenuator

Optional Attenuator

Before deciding whether an attenuator is required in front of the sensor power meter, the power level at the output of the calibration jig must be calculated first.

Why a factor of 6 applies

Two effects reduce the test voltage before it appears at the 50 Ω measurement port:

• Impedance conversion (150 Ω → 50 Ω): factor of 3
• Open-circuit to loaded conversion: factor of 2

Combined, this gives a total factor of 6:

$V_{\text{port}}={\frac {V_{\text{test}}}{6}}$

Conversion from test level (dBµV) to jig output (dBµV)

$L_{\text{port, dBµV}}=L_{\text{test, dBµV}}-20\log _{10}(6)$

${\displaystyle L_{\text{port, dBµV}}=L_{\text{test, dBµV}}-15.56\,{\text{$dB}}}

Conversion to power in dBm

${\displaystyle P_{\text{$dBm}}=L_{\text{port, dBµV}}-107\,{\text{dB}}}

Short form

By combining the steps:

${\displaystyle P_{\text{$dBm}}=L_{\text{test, dBµV}}-122.56\,{\text{dB}}}

Examples

The following table shows the results for common test levels:

Test Level (V, rms)	Test Level (dBµV)	Jig Output (dBµV)	Power (dBm)
1	120.0	104.44	−2.56
3	129.54	113.98	+6.98
10	140.0	124.44	+17.44

Conclusion

Using the calculated power levels, it is straightforward to determine the amount of attenuation required for a given sensor power meter.

For example, the Raditeq RPR2006C has a specified measurement range up to +10 dBm.

• At 1 V and 3 V test levels (−2.56 dBm and +6.98 dBm), no attenuation is required.
• At 10 V test level (+17.44 dBm), the input exceeds the safe range by approximately 7.5 dB.

In this case, adding at least a 10 dB attenuator ensures the sensor operates within its specified limits. Make sure to correct for this 10 dB by creating a cable device driver with a correction file attached to it, then configure this cable in the test site: Cables, Cable current -> power meter.

Configure the injection device and jig device driver

In order for RadiMation to calibrate on the correct test level, the injection device and jig device driver must be configured correctly.

Jig device driver

For a 150 Ω system the resistance is 150 Ω or uses a jig factor of 9.5 dB.

Injection device driver

For the injection device driver the impedance should also be set to 150 Ω if that is configurable.

Configure the calibration

The calibration can be configured and started from the menu by selecting:

    Calibration

       System calibration

          Conducted immunity

Start

The start frequency of the calibration. For example 150 kHz.

End	The stop frequency of the calibration. For example 80 MHz.

Step	The frequency step, in this case 1%.

Test level

The test level, in this case Voltage.

Voltage

The voltage test level, 1 V, 3 V or 10 V.

Tolerance

The regulation tolerance.

Calibration method

The power measurement that should be the result of the calibration: Forward power

Test equipment

Calibration test equipment.

Test engineer

The engineer that performed the calibration.

When the calibration has finished, RadiMation^® will ask to store the calibration file.

EUT Test

EUT testing equipment

The configuration of the RadiMation^® 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
	Injection device	Devices 2	The injection clamp or CDN to use

Configure the EUT test

To perform the actual test on the EUT, create a conducted immunity multiband test. The conducted immunity multiband test configuration, can be opened by selecting from the menu:

    Tests

       Conducted Immunity

          Multiband

Start

The start frequency of the test. For example 150 kHz.

End	The stop frequency of the test. For example 80 MHz.

Frequency Step

The frequency step, 1%.

Dwell Time

The dwell time.

Frequency Change Mode

The method that is used to change from one to the next frequency: Constant.

Modulation

Configure Amplitude Modulation with 1 kHz and 80 % duty cycle.

Test equipment

The equipment needed for the conducted immunity test.

Location Type

Injection clamp.

Test Level

Specify the Voltage substition method

Inputs

No inputs are needed, this is optional.

To configure the modulation settings click Config next to the modulation settings, click the AM tab, and enter the amplitude modulation settings.

Activate modulation

Check this checkbox to enable the amplitude modulation.

Frequency

The AM frequency 1 kHz.

Duty Cycle

A depth of 80 %.

Also apply modulation out of the dwell-time period

No need to apply modulation out of the dwell-time period.

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

Description

The description of the test level.

Calibration file

Select the calibration file created during the calibration procedure.

Test level

Constant voltage, 1 V, 3 V or 10 V.

Calibration method

Select Forward Power.

Tolerance

Specify the tolerance to use.

When all settings 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.

Conclusion

The IEC 61000-4-6 calibration can be performed by using the Conducted immunity calibration. The RadiMation® Conducted immunity multiband test can then be used to perform the IEC 61000-4-6 EUT test with a calibration file in the EUT test.

Institute of Electrical and Electronics Engineers

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.

Equipment Under Test

Coupling Decoupling Network

Decibel

Power expressed in milliWatt in dB values.

• 1 mW = 0 dBm

• 2 mW = 3 dBm

• 100 mW = 20 dBm

• 1 W = 30 dBm

• 100 W = 50 dBm

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.