Dual-Band Planar Microwave Solid Complex Dielectric Constant Sensor System Based on E-Interdigital Structure.

Area of Science:

• Electrical Engineering
• Materials Science
• Microwave Engineering

Background:

• Accurate measurement of complex dielectric constant is crucial for material characterization.
• Existing methods may be sensitive to environmental variations or require complex setups.

Purpose of the Study:

• To introduce a novel dual-band planar microwave sensor system.
• To enable precise measurement of the complex dielectric constant of solid materials.
• To develop a system with inherent environmental compensation capabilities.

Main Methods:

• Design of a sensing probe with E-interdigital structures exhibiting dual resonant frequencies (3 GHz and 3.92 GHz).
• Integration of a circuit module for signal generation and processing.
• Utilizing a broadband coupler for signal differentiation.
• Operating principle based on resonant frequency and peak attenuation variations.

Main Results:

• A prototype sensor system was fabricated and tested.
• The system demonstrated high sensitivity in measuring the complex dielectric constant.
• Differential operation effectively mitigated environmental influences.
• The sensor achieved accurate measurements independently.

Conclusions:

• The proposed dual-band planar microwave sensor system is effective for dielectric property measurement.
• The design offers high sensitivity, low cost, and environmental robustness.
• The system's independence from auxiliary equipment enhances its practicality.