Measurement technology of complex permittivity based on split resonant cavity and hybrid field solution

Area of Science:

• Electromagnetics
• Materials Science
• Measurement Technology

Background:

• Characterizing complex permittivity is crucial for material analysis.
• Traditional methods often require specific sample fabrication and can be destructive.
• Developing non-destructive techniques with high accuracy remains a challenge.

Purpose of the Study:

• To propose and validate a new measurement technology for complex permittivity.
• To enable non-destructive testing of planar materials.
• To overcome limitations of traditional resonant cavity methods.

Main Methods:

• Utilizing a split resonant cavity operating in TE01p modes (p=1, 3, 5) within the 2-7 GHz range.
• Employing a hybrid field solution combining cylindrical cavity fields and eigenmode expansion for electromagnetic analysis.
• Applying the mode-matching method for precise complex permittivity determination of planar samples.

Main Results:

• The split resonant cavity achieved a high quality factor (7×10^4), ensuring good frequency selectivity and testing sensitivity.
• The proposed hybrid field solution and mode-matching method accurately determined complex permittivity.
• Both simulation and experimental results confirmed the high measurement accuracy of the developed technology.

Conclusions:

• The developed measurement technology based on a split resonant cavity is highly accurate for non-destructive characterization.
• The open design of the split cavity eliminates the need for specific sample sizes, enhancing versatility.
• This technique is well-suited for evaluating the complex permittivity of various planar materials.