RF amplifier , testing, conversions and distance for EUT

qu1nn · Jun 18, 2003

I think that I got my self confused in the units, and I am kind of new with this so you will have to bear with me....

----------Goal----------
To rent test equipment in order to perform immunity tests similar to IEC 61000-4-3
(3V/m, 26Mhz to 1GHz, 1kHz sine +/- 80%) to work out any bugs before the device goes for official testing.

-------Layout--------------
Signal Generator ---> RF Amplifier ---> Antenna

---- my logic/questions --------------
Typically the Generator has a RF output of about 13dBm ( if my conversions are correct this is equivalent to 0.02W or 120dBuV )

Since the EUT test requires a level of 3V/m ( if my conversions are again correct this is equal to 9.5dBv or 129.5dBuV)

How do I calculate what size amplifier I need along with the distance requirement?

My guess is that at the output of the signal generator I could obtain a maximum of 1V...neglecting antenna gain/loss if I were to move 1m away from the signal generator my power would be cut in half or 0.01W which would now have a signal strength of 117dBuV, or 0.71V/m. Thus if I want a level of 3V/m at say 1m so I would want an output of 6V/m or 135.5dBuV ???

Also if a an RF amplifier says that it will provide 20dB of gain... how do I calculate what the total output power?
is it just 13dBm + 20dB = 33dB ???

If I am a couple of meters away and there is free air propagation, how much free air loss can I expect?

Thanks for your time
Qu1nn

Qu1nn

jbartos · Jul 5, 2003

Suggestion: Visit

http://rf.rfglobalnet.com/library/ApplicationNotes/files/4/teststandards.htm

for:
EN 50082-1: "New Approach" generic European standard that provides radiated immunity field levels for electronic apparatus intended for use in residential, commercial, and light industrial environments. Calls out IEC 801-3 as the basic testing document to be used.

EN 50082-2: "New Approach" generic European standard that provides radiated immunity field levels for electronic apparatus intended for use in the heavy industrial environment. Calls out IEC 1000-4-3 as the basic testing document to be used.

http://www.compliance-club.com/archive1/020913.htm

http://www.interbusclub.com/en/doku/infoservice/r4_003a.pdf

http://www.delta.dk/hampiis/hampiisdenfinal.pdf

https://domino.iec.ch/webstore/webstore.nsf/artnum/029184

https://domino.iec.ch/webstore/webstore.nsf/artnum/029067

http://www.iec.ch/webstore/best/sellers_2003/norm_refs/nrefs_61000-4-3.htm

http://www.dlsemc.com/index.htm?emc/testing/ec/en61000_4_03/03.htm~mainFrame

etc. for more info

The following equation:
13dBm + 20dB = 33dB ???
has to have the same dimensions on the left side and on the right side.