H-field probe: how to characterize with up to GHz magnetic field?

[BelgianEngineer]

Hey all,

I've built a set of near-field (H-field) EMC probes which I would like to characterize. I noticed that a common characterization curve is the amplitude vs. frequency for a fixed magnetic field curve (see page 4: https://www.beehive-electronics.com/datasheets/100SeriesDatasheetCurrent.pdf). Does anyone has an idea on how they manage to generate an oscillating magnetic field up to such a high frequency (>1GHz)?

I was tempted to think that an Helmholtz coil directly driven by a signal generator/tracking generator would do the trick but looking a bit more into it, it seems difficult to reach that kind of frequency due to the increasing coil impedance with frequency.

Alternatively i looked at characterizing the probes on a 50Ohm microstrip driven by a signal generator but that does not seem to be a commonly used approach and I doubt I can make any assumptions on a fixed magnetic field intensity with that setup.

I am looking into making a DIY solution if possible such that I learn a bit with it at the same time 

Any lead is welcome!

[knudch]

Try to look into TEM or GTEM cells

They are very often used for calibration of field sensors

[BelgianEngineer]

Try to look into TEM or GTEM cells

They are very often used for calibration of field sensors

Wouldn't TEM or GTEM cells usually be used for electric field characterization rather than magnetic field? How would you go at showing the response of a H-field probe to 0.1uT at different frequencies with them? 

[knudch]

As TEM & GTEM has far field condition....both magnetic and electric field strength are predictable (upper sit orientation )

But you are challenge by that factor how well your sensors suppress electrical field
So will it also been in the application of the sensors

[knudch]

Suppression of electrical field:

That's why magnetic sensors often has a electrical shielding build in

You can get an indication of field suppression by turning the probe 90 deg  (in the TEM/GTEM cell)

[knudch]

A simple way to get an reasonable idea of transfer function is to place 2 identical probes on top of each other and measure the transfer function, divide by 2

Measuring magnetic field strength reliable in xxx MHz range will anyway in practice be challenging