Langer EMV-Technik GmbH has introduced the ICR family of near-field microprobes covering a frequency range from 0.5 MHz to 6 GHz with a resolution of 60 µm to 300 µm. Near-field probes have become indispensable in the development of electrical assemblies. They are used successfully in both high-frequency technology and EMC technology. They are used to evaluate simulation values, locate sources of interference and carry out real-time monitoring.
Near-field probes have the following advantages:
- a low feedback effect on the measuring system due to contactless measurement
- versatile application possibilities due to optimized tip design
- due to their small size, even structures that are difficult to reach can be examined
- near-field probes cover a broad frequency spectrum
- the probes can be used for measurements in the frequency and time range
- easy handling
These advantages make integrating the near-field probes into the development process easy. Another aspect and the greatest advantage of near-field analysis is the possibility of investigating various interactions in assemblies (e.g. magnetic fields). The magnetic field and the electric field can be measured separately. This makes it possible to assess the effect of the electric field separately from the effect of the magnetic field. The associated gain in degrees of freedom for assessing the correlation of effects is considerable, as distributions of currents and voltages can also be derived from the field distributions.
To utilize this advantage of near-field measurement, Langer EMV-Technik probes are designed in such a way that magnetic field probes, for example, are shielded against (the penetration of) electric fields. The ICR probes are designed to measure magnetic and electric near fields with extremely high resolution and sensitivity. An integrated preamplifier in the probe housing, powered by the BT 706 Bias Tee, ensures optimal performance. Additionally, the probes support the collision protection function of Langer scanners, which automatically stop movement when the probe touches the test object.
Another positive aspect of near-field measurement with near-field probes is the spatial resolution of measured values. Depending on the size of the near-field probe, measurement volumes can be measured with a higher or lower resolution. For example, the field distribution of entire assemblies and the smallest circuits can be measured and displayed graphically. The near-field microprobes of the ICR series are particularly suitable for the field distribution of circuits. These probes are characterized by a high spatial resolution of approx. 60 to 300 µm. With this resolution, field distributions of integrated circuits can be recorded and evaluated. Figure 1, for example, shows the field distribution of the processor chip of a Raspberry Pi at different spectral frequencies. The field distributions result from the internal switching processes of the IC.
Figure 1: Field decoupling measured with ICR HH150-27 at 25 MHz vs with ICR HH150-27 at 163.7 MHz
The figures show the different activities of the circuit at different frequencies. These activities reflect the processes and functions of the circuit and depend, for example, on the technology of the IC and the software or firmware. In comparison, the field distribution of the memory circuit of the Raspberry Pi shows the diversity of the structure.
Figure 2: Field decoupling measured at memory IC with ICR HH150-27 at 18 MHz vs ICR HH150-27 at 24 MHz
Figure 2 shows the activity of the IC distributed over the entire chip surface. It is generated by the function of the IC distributed over the chip.
Under the aspect of:
- Fault diagnosis
- quality assurance
- Optimization of integrated circuit components
this type of near-field testing is an asset not only in development but also in troubleshooting finished devices.
The advantages of the high spatial resolution and the wide frequency range are particularly useful in the investigation of safety-critical functions of integrated circuits. This is currently being used particularly in the area of circuit security. In so-called side-channel attacks, circuits are exposed to certain signals in the time domain and the reaction of the circuit is investigated at various positions using field strength increases. Langer EMV-Technik offers not only near-field probes for measuring the reaction but also pulsed field generators for feeding in the interference signals. The spatial resolution of the injected pulsed fields is also in the range of approx. 200-300 μm.
Applications of ICR Probes:
- High-resolution emission measurements over boards and ICs
- Security technology, side-channel analysis
Near fields are one of the most important sources of information for basic EMC investigations. Therefore, near-field probes are the eyes of the developers within the device.
Click here to learn more about the ICR family of near-field microprobes.
Click here to find Near Field Probes from the leading manufacturers.
