Closed Aperture Current Probe - CP0

The RF Current Prove CP0 is intended as an evaluation model of the CP1 and CP2 current probes. It is simplified in its construction and therefore does not yield the same performance. The 3d files for the 3d printed body and the assembly instructions are freely available.

Commerical use (ie. selling the physical current probe) is prohibited. However, building and using probes in academia, education, hobby,... is encouraged.

Calibration

Before using the probe, your newly built measurement tool needs calibration to characterize its transfer impedance.

Here I discuss the calibration procedure using a vector network analyzer or a signal generator and some "voltmeter" (your spectrum analyzer will do). Instead of a nice calibration fixture, you can use short wires to measure the current through a 50Ω resistor.

Typical Performance

As shown above, this simple probe is perfectly usable for typical EMC measurements from 150k-30MHz. With some caution, even monitoring power levels up to 80MHz for conducted immunity applications is possible.

This measurement was done using the CP1 calibration fixture.

Remarks

The 3d model was optimized for printing with 0.28mm layer heigt using a 0.4mm nozzle.

Downloads

File	Description
CP0-3dFiles_Rev1.zip	The 3d files
CP0-Assembly_Rev1.pdf	The assembly instructions

Last updated 2024-11-21