Near-field probe measures magnetic fields up to 10 GHz

September 24, 2015 // By Jean-Pierre Joosting
The high measurement resolution of the SX probe heads from Langer EMV-Technik allows the developer to pinpoint RF sources of between 1 GHz and 10 GHz on densely packed printed circuit boards or on IC pins.

The compact pin shape of the EMC near-field probes provides the developer with convenient working conditions on a PCB.

High clock rates of 2 GHz, for example, may result in 5th order harmonics of up to 10 GHz. These harmonics are coupled out by RF sources on the PCB such as conductor sections, ICs and other components. They may stimulate other structural parts of the PCB to resonate and generate emissions. In view of the high internal fundamental frequency of current PCBs, the measurement of harmonics of this frequency is an important step towards reliable EMC.

The latest SX1 near-field probe set contains three near-field probes with high resolution for measurements in the upper frequency range.

The SX-E 03 is an E-field probe for frequencies between 1 GHz and 10 GHz with an electrode on the underside of the probe head sized approx. 4 x 4 mm. This probe can be used to pinpoint small E-field sources such as conductors, individual components on a printed circuit board, etc. The head of the near-field probe is usually placed directly on the object of the measurement (high electric field strength).

The SX-R 3-1 is an H-field probe for frequencies between 1 GHz and 10 GHz with a very small probe head to identify even the smallest components as a source of interference. This small probe head is also ideal for carrying out measurements in hard-to-reach locations such as in the vicinity of IC pins. The SX-R 3-1 detects magnetic field lines that emerge from the object of the measurement in an orthogonal direction. Magnetic field lines that enter the probe sideways are not detected. What is new in the SX 1 set is the SX-B 3-1 H-field probe for frequencies between 1 GHz and 3 GHz whose measurement coil is arranged orthogonally to the probe shaft and thus rests directly on the surface of the printed circuit board when the probe head