Talk:RadiMation Application Note 104

Isn't the performing of a current sensor calibration, not simply performing a cable calibration using the attenuation/gain calibration module? The determined attenuation is a little bit higher than a standard cable, but the principle is the same.

Joro 09:13, 6 October 2015 (UTC)

Another idea: What does Google say on: "how to calibrate RF Current sensor"?

Joro 09:14, 6 October 2015 (UTC)

See: http://fischercc.com/productfiles/Current_Probe_Calibration_Rev_A_001c.pdf It is a very good description on how the current sensor can be calibrated. In RadiMation this is a cable attenuation test. Then the result is a positive cable loss. The sign of that cable loss should be inverted (-), and +34 dB should be added. This results in a dBOhm transfer impedance, which can be specified in the 'Resistance' column in a Correction file.

As a verification a Fixed signal power test at 0 dBm can be performed, while the current is also measured with the current sensor and the sensor powermeter. The measured current should be 4.4 mA. Psg == 0 dBm = I*I * R. I = sqrt(P/R) = sqrt( 1 mW / 50) = 4.4 mA.

Sast 12:51, 6 October 2015 (UTC)

The link to the fishercc.com document is not present anymore. Probably we can still find it, but we have to search it again. JORO should determine the correct procedure on how to do this current sensor calibration. Based on that we can explain how to do it with RadiMation. The correct link to Fischer CC document is: https://www.emctest.it/public/pages/strumentazione/elenco/TEGAM/91550-4%20-%20Current%20Probe/Manuali/Current%20Probe%20Calibration%20-%20Rev%20A%20001c.pdf

Another good page is: https://design-4-emc.com/2013/01/22/question-on-current-probe-calibrations/

The good procedure is probably:

• use a signal generator and powermeter (preferrable a powermeter driver that is using a spectrum analyzer)
• perform an attenuation/gain system calibration
• Attach the signal generator to the calibration jig
• position the current sensor in the calibration jig
• Attach the powermeter to the current sensor => Include a schematic drawing.
• Perform the attenuation/gain EUT calibration
• The result is the dB loss for the current sensor, however it should be converted to dB Ohm.
• Show the formula to perform the conversion => Convert the sign and Add 34 dB to get dBOhm
• Export the attenuation to excel, add 34 and paste back into correction file, which uses dBOhm resistance unit.
• Connect the correction file to the current sensor

Validation can be performed by doing with same setup a 0 dBm signal power test, and measure the current. The expected current should be: 4.4 mA (See formula's of SAST above).

The application note should also include the formula's to explain the idea...

Joro (talk) 10:04, 29 January 2019 (CET)

Radio Frequency

Decibel

Resistance expressed in Ohm in dB values.

• 1 Ohm = 0 dBOhm

• 2 Ohm = 6 dBOhm

• 10 Ohm = 20 dBOhm

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

Equipment Under Test