Provide support for materials science research
When optimizing materials or equipment, an important step is to measure the dielectric properties. Measuring the dielectric constant allows us to determine the following material properties:
Changes (caused by aging, temperature, humidity, and pressure)
Transparency at specific electromagnetic frequencies (e.g. checking the transparency of a car bumper at radar frequencies)
Compatibility with circuits (e.g. ensuring PCB materials are compatible with RF circuits)
consistency
There are two different instruments that can measure dielectric properties, depending on the specific video rate range.
Impedance analyzers are typically used in the frequency range from millihertz to low megahertz. This low frequency is sufficient to cover many application scenarios.
Vector Network Analyzer (VNA) is more suitable for materials used in the frequency range from higher megahertz to gigahertz. For measurements in the terahertz range, a combination of VNA and up converter can be used.
Testing solutions from millihertz to terahertz
Rohde&Schwarz has accumulated profound expertise in RF technology, providing strong support for materials science research. In July 2021, Zurich Instruments joined the Rohde&Schwarz family. Zurich Instruments has developed various impedance measurement and material science solutions, greatly improving Rohde&Schwarz's product portfolio.
Impedance Analyzer - Low Frequency Measurement
Dielectric has polarization and is an electrical insulator with low conductivity in DC state. Dielectric materials can store charges in the low-frequency and mid frequency ranges. This capacitance effect allows dielectrics to be used for the storage and dissipation of charges. Understanding the dielectric constant of materials used in capacitor or thin film dielectric applications is crucial, such as:
Low loss electrical components
Energy storage devices, such as supercapacitors
High dielectric constant gates and low dielectric constant gates in semiconductor devices
Piezoelectric and ferroelectric sensors and transducers
In order to fully understand the physical properties of materials and optimize equipment performance, it is necessary to conduct impedance research on dielectrics.
Impedance analyzers are highly suitable for low-frequency measurements. The MFIA of Zurich Instruments can measure and calculate impedance parameters such as dielectric constant and loss factor in the frequency range of 1 mHz to 5 MHz.
When using an impedance analyzer for dielectric characterization, a sample with a specific geometric structure is in contact with two electrodes. This usually requires the use of parallel flat fixtures. For such geometric structures, the dielectric constant (relative dielectric constant) can be obtained based on the ratio of material capacitance to air capacitance.
Vector Network Analyzer (VNA) - High Frequency Characterization
High frequency characterization requires the use of VNA. The specific measurement method depends on the required frequency range, measurement speed, and accuracy. There are four commonly used measurement methods:
Transmission/reflection method
Free space method
Open coaxial probe method
Resonance (cavity) method
The physical and dielectric properties of materials are also important. For example, is the material solid, liquid, or powder? Is the temperature of the material high? Is the shape special? These characteristics have a significant impact on the selection of appropriate characterization methods.
The measurement method will also determine the material sample fixtures required in addition to VNA.
Understand material characterization equipment
The impedance analyzer and vector network analyzer of Rohde&Schwarz and Zurich Instruments cover the entire frequency range required for materials science research.
View our product portfolio and find suitable tools for analyzing passive and active devices:
A multifunctional and high-performance network analyzer with a frequency of up to 1.1 THz
Standard multi port solution, providing up to 48 ports
Impedance analyzer, supporting low frequency and high impedance ranges,