High-Sensitivity Differential Sensor for Characterizing Complex Permittivity of Liquids Based on LC Resonators

Area of Science:

• Electrical Engineering
• Materials Science
• Sensor Technology

Background:

• Accurate measurement of complex permittivity is crucial for characterizing liquid materials.
• Microstrip sensors offer potential for non-invasive dielectric analysis.
• Existing sensor designs may lack sufficient sensitivity or sample interaction.

Purpose of the Study:

• To develop a high-sensitivity microstrip differential sensor for liquid complex permittivity measurement.
• To optimize sensor design for enhanced interaction with dielectric samples.
• To validate the sensor's performance using ethanol-water solutions.

Main Methods:

• Designed a differential sensor by cascading two LC resonators on a stepped impedance microstrip transmission line.
• Incorporated a cylindrical micropore in the LC resonator's circular patch to house the dielectric sample.
• Optimized resonator dimensions and measured transmission coefficients for varying ethanol-water concentrations.

Main Results:

• The designed sensor demonstrated high sensitivity to changes in complex permittivity.
• Accurate measurements of complex permittivity for ethanol-water solutions were achieved.
• The average sensitivity of the sensor reached 0.76%.

Conclusions:

• The proposed microstrip differential sensor is effective for high-sensitivity liquid complex permittivity measurement.
• The sensor design, featuring LC resonators and a sample-optimized micropore, enhances dielectric analysis.
• This technology holds promise for various applications requiring precise liquid material characterization.