The RF-K 7-4 near-field probe detects circularly curved magnetic field lines that enter the probe head in opposite directions. Such magnetic field lines occur, for example, on cables, rod-shaped structural parts, cable connections and the edges of flat structural parts. The probe works in a similar way to a current coupling clamp.
The RF-K 7-4 is a passive near-field probe. Compared to the RF-U 5 near-field probe, the RF-K 7-4 H-field probe is shielded against field lines hitting the probe head from the side. The near-field probe detects inhomogeneous magnetic fields that enter the base of the probe head. Superimposed homogeneous fields are not detected by the special probe head. Like the RF-U 5 H-field probe, the RF-K 7-4 H-field probe works in a similar way to a current coupling clamp. The near-field probe is small and easy to handle. It has a sheath current attenuation and is electrically shielded. The near-field probe is connected to a spectrum analyzer or an oscilloscope with a 50 Ω input. The H-field probe does not have an internal 50 Ω terminating resistor.