Langer EMV - Shielding Measurement System

Shielding Measurement System

The Shielding Measurement System (SDM) enables reproducible measurement of the shielding effectiveness of thin, conductive shielding materials and analysis of their material properties. Local inhomogeneities and differences in shielding effectiveness depending on material orientation (anisotropy) can also be measured.

Shielding Effectiveness Based on the Langer Method - Reliable material characterization for magnetic near-field shielding

Langer EMV-Technik GmbH introduces a new test and analysis system for evaluating the shielding effectiveness of conductive materials against magnetic near fields. The system is designed for material development, comparison and quality assurance — especially for manufacturers of EMC shielding materials, test laboratories and R&D teams requiring reliable magnetic field shielding.

Test station for magnetic near-field shielding measurements — **Figure 1:** Test station for evaluating the shielding effectiveness of conductive materials against magnetic near fields.

Measurement principle

The test station uses a new measurement principle based on two coupled microstrip lines. The sample is positioned between them. The first microstrip line is fed by a current, generating a magnetic field, which induces a voltage in the second microstrip line.

By comparing the signal with and without the material, the shielding effectiveness is determined directly. This provides a reproducible, high-resolution and material-focused method for gaining deeper insight into shielding performance.

Key Advantages

Wide frequency range: Measurement from 30 kHz to 1 GHz with a dynamic range of more than 100 dB.

**Figure 2:** Nonwoven and woven shielding materials used for comparison of material structure.

**Figure 3:** Shielding effectiveness over frequency for copper, nonwoven fabric and woven fabric; below 1 MHz the woven and nonwoven materials show nearly no shielding effect.

Excellent reproducibility: Defined measurement geometry ensures stable results without setup-dependent variations.
Direct material evaluation: Determines material-related shielding parameters instead of system-dependent values.
Better insight for material development: Supports material optimization — not just a single attenuation value.
High spatial resolution: Detects local inhomogeneities and variations in material structure or coating quality.
Detection of anisotropy: Identifies direction-dependent shielding behavior, e.g. in structured, woven or process-oriented materials.

Direction-dependent shielding effectiveness and material inhomogeneities — **Figure 4:** Direction-dependent shielding behavior and material inhomogeneities can lead to differences in shielding effectiveness.

Defined sample compression: Measurements can be performed under controlled force to evaluate material behavior under realistic mounting conditions.
Smaller sample size: Requires less material than many established methods and reduces preparation effort.
No point-based fixation effects: Unlike conventional specimen holders with localized clamping or screw fixation, the Langer method uses flat, area-based specimen support to reduce mechanical influence on the material.

Conventional shielding measurements often depend strongly on the test setup, sample holder or mounting conditions. The Langer method reduces these influences and delivers highly comparable, reproducible and application-relevant results.

The result: better comparability, deeper material understanding and more effective shielding solutions.