Conducted immunity fixed voltage algorithm

Question

What is the algorithm that is used for the Conducted Immunity Fixed Voltage test?

Answer

Algorithm

The following steps are taken in the Conducted Immunity Fixed Voltage test:

1. Initialize all the equipment that should be used
2. Set the carrier frequency to the first frequency
3. Determine the Voltage level that should be levelled:
   • Fixed voltage test level
   • Variable voltage test level: Retrieve value from specified correction file
4. Determine the maximum accepted voltage test level:
   • Maximum accepted voltage test level = 10 ^(20 * Log10(VoltageTestLevel) + Tolerance) / 20^
5. Set the signal generator to the lowest carrier level
6. Regulate the power level to the new power level, while regulating to the power level, monitor the injected current, and stop regulating if the specified current level is reached.
7. Measure the voltage input. Depending on the configured 'Voltage measuring device':
   • Multimeter
     1. Read out the multimeter for the measured voltage
8. Oscilloscope
   1. Retrieve a measurement of the oscilloscope
      1. Quadrate all the values of the measurement, and add them to eachother to a total
      2. Divide the total by the number of points in the measurement
      3. Take the square root of the divided total.
9. Sensor power meter
   1. Retrieve the power measured at the powermeter (optionally corrected by the correction file, that is attached to the used powermeter)
      1. Convert the measured power to Watt
      2. Multiply the value in Watt by 50 Ohm, and take the square root
10. Spectrum analyzer
    1. Select the peak detector
       1. Select Auto RBW and Auto VBW
       2. Select Zero span, on the tested carrier frequency
       3. Take sweep with the spectrum analyzer
       4. Determine the maximum measured dBuV level during the sweep
       5. Correct the maximum value with the value that is specified in the correction file that is attached to the used spectrum analyzer)
       6. Convert the value to Volts
       7. Divide the maximum measured Volts value by the square root of 2. (to calculate the correct RMS voltage)
11. If the power is out of the accepted range (step 3. and 4.), and the current is below the specified current limit, adjust the signal generator level and continue at step 6.
12. Calculate if the power level should be changed to apply 'modulation conservation'
13. Measure the AD channels for the 'Before' measurement
14. Adjust the power level for the 'modulation conservation'
15. Measure:
    • Forward power
    • Reflected power
16. Turn the specified modulation on (if specified)
17. Wait the specified dwell time
18. Measure the AD convertors for the 'During' measurement
19. Turn the modulation off
20. Measure:
    • Voltage (See step 7)
    • Current
21. Check if the test should be stopped, or Manual mode should be activated
22. Go to the next frequency and continue at step 3.
23. Deinitialize all the equipment that is used

Used Equipment

Device Type	Optional	Tab-blad
Signal Generator	Needed	Standard 1
Amplifier	Needed	Standard 1
Forward Power meter	Optional	Standard 1
Reflected Power meter	Optional	Standard 1
Coupler	Needed when Forward or Reflected power meter is used	Standard 1
Switch matrix	Optional	Standard 1
EUT Controller	Optional	Standard 1
AD Convertor	Optional	Standard 2
Cables	Optional	Cables

A voltage measuring device must be used. Which Device type is used for the measuring of the voltage is depending on the selection of the 'Voltage Measuring device' in the TSF-File of the test-configuration. The voltage measuring device can be one of:

Device Type	Optional	Tab-blad
Multimeter	see note above	Standard 1
Oscilloscope	see note above	Standard 1
Spectrum analyzer	see note above	Standard 2
Sensor Power meter	see note above	Standard 2

If besides the voltage measuring, also the 'current' needs to be measured, the following equipment is also needed:

Device Type	Optional	Tab-blad
Sensor power meter	Needed	Standard 2
Current Sensor	Needed	Standard 2

Some random remarks:

1. If the 'Sensor power meter' is used for measuring the Voltage or the current, this can be a real powermeter, but it can also be spectrum analyzer that is controlled through a powermeter device driver. For most spectrum analyzers, also a device driver to control the spectrum analyzer as a powermeter is available.
2. Depending on the used setup, a coupling device will be used to inject the generated power into the cables of the EUT. This 'coupling device' is not included in the list of used equipment.
3. If the Sensor power meter is used as the voltage measuring device, it is not possible to also measure the current.