Material Characterization

Material Characterization

Material characterization techniques and applications

Supporting material science research

Measuring dielectric properties is an important part of optimizing a material or device. By measuring the dielectric constant, it is possible to establish the following material properties:

  • Changes due to aging, temperature, humidity and stress
  • Transparency at certain electromagnetic frequencies (e.g., checking the transparency of a car bumper at radar frequencies)
  • Compatibility to circuits (e.g., ensuring that PCB materials are compatible with RF circuits)
  • Consistency

There are two different instruments for measuring dielectric properties. The choice depends on the frequency range.

  • Impedance analyzers are commonly used in the mHz to low MHz ranges. For many real-world applications, low frequencies are enough.
  • Vector network analyzers (VNA) are more suitable for materials used at higher MHz to GHz ranges. For measurements in the THz range, a VNA can be combined with up-converters.
Test solutions from mHz to Thz
Test solutions from mHz to Thz

Rohde & Schwarz supports material science research with its strong background in RF technology. In July 2021, we also welcomed Zurich Instruments to the Rohde & Schwarz family. Zurich Instruments provides impedance measurement and material science solutions that perfectly complement the Rohde & Schwarz portfolio.

Impedance analyzer - low frequency measurements

A dielectric is an electrical insulator with a very low conductivity at DC because of its polarizability. It can also store charges in the low and mid frequency ranges. This capacitive effect makes dielectrics useful for charge storage and dissipation. It’s important to understand the dielectric constant of a material being used in a capacitor or thin-film dielectric applications, such as:

  • Low-loss electrical components
  • Energy storage devices, such as supercapacitors
  • High-k and low-k gates in semiconductor devices
  • Piezo- and ferro-electric sensors and transducers

An impedance study of dielectrics is necessary to fully understand the material physics as well as to optimize device performance.

An impedance analyzer is the instrument of choice for measurements at low frequencies. The Zurich Instruments MFIA can conduct measurements over a frequency range of 1 mHz to 5 MHz and calculate impedance parameters, such the dielectric constant and dissipation factor.

Dielectric characterization with an impedance analyzer is carried out on a sample with a well-defined geometry, contacted with two electrodes. Typically, this is achieved with a parallel plate fixture. Based on this geometry, the dielectric constant (permittivity) can be extracted, since the dielectric constant is the ratio of the material capacitance to the air capacitance.

Vector network analyzer (VNA) - high frequency characterization

High frequency characterization requires a VNA. The measurement method depends on the required frequency range and the desired measurement speed and accuracy. The four most commonly used methods are:

  • Transmission/reflection method
  • Free space method
  • Open-ended coaxial probe method
  • Resonant (cavity) method

The physical and dielectric properties of the material are also important. For example, is the material a solid-state material, a liquid or a powder? Is it very hot, or does it have a particular shape? These properties have a strong influence on which characterization method is the most suitable.

The measurement method also determines the material sample fixtures that are needed in addition to the VNA.

Explore material characterization equipment

Rohde & Schwarz and Zurich Instruments provide impedance analyzers and vector network analyzers that cover the entire frequency range needed for material science research.

Browse our portfolio and discover the perfect tools for analyzing passive and active components:

  • Versatile, high-performance network analyzers that go up to 1.1 THz
  • Standard multiport solutions up to 48 ports
  • Impedance analyzers capable of covering the low frequency and high impedance range that is beyond traditional impedance analyzers

Benefits of our material characterization instruments

Rohde & Schwarz material characterization solutions cover a uniquely wide frequency range. We work with reliable test fixture suppliers who provide drivers for our solutions - making our instruments plug-and-play. Additional benefits include:

  • Efficient, high-speed measurements
  • Easy configuration and operation
  • Seamless integration into existing setups
  • Ongoing support and technical resources

Related Products

Impedance Analyzers

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Vector Network Analyzers

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Related content for material characterization

Webinar: Measuring dielectric properties of material

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