How To Use an Electromagnetic Probe

AKA EM probe, H-field probe, RF probe…

All of our target boards are all designed to allow you to obtain power traces from a shunt resistor. On some other targets, this is not possible; one solution is to instead measure the electromagnetic field using a probe such as our CW505 H-Field Probe.

Whether you’re using our probe or a third-party probe, start by reviewing the CW505 page linked above. It includes a video that provides hints for positioning the probe. The quality (SNR) of the traces you’ll get is highly depending on probe placement; this is the tricky part of using these probes. Some trial-and-error (and patience) is required.

The video uses the old ChipWhisperer GUI (which is no longer supported) but the principles are the same. For modern ChipWhisperer installations, we have a new demo notebook.