Chipless RFID Sensor for Measuring Time-Varying Electric Fields Using a Contactless Air-Filled Substrate-Integrated...

Area of Science:

• Electrical Engineering
• Electromagnetics
• Sensor Technology

Background:

• Accurate measurement of external time-varying electric fields is crucial for various applications.
• Existing methods may lack wireless capabilities, long-range interrogation, or compact form factors.

Purpose of the Study:

• To develop and demonstrate a wireless, chipless resonator-based sensor for absolute measurement of external time-varying electric fields.
• To utilize contactless air-filled substrate-integrated waveguide (CLAF-SIW) technology for enhanced performance.

Main Methods:

• The sensor employs a low-impedance electromagnetic band gap structure within an air cavity.
• Varactor diodes in the air cavity are modulated by the external electric field, altering the resonant frequency.
• Contactless air-filled substrate-integrated waveguide (CLAF-SIW) technology is used for fabrication.

Main Results:

• The fabricated CLAF-SIW sensor prototype successfully measured time-varying electric fields up to 6.9 kV/m.
• Achieved a sensitivity of 1.86 (kHz)/(V/m) and demonstrated interrogation from 80 cm.
• The sensor exhibits a high unloaded quality factor and a feasible bandwidth of 25 kHz.

Conclusions:

• The proposed wireless chipless resonator sensor offers a compact, planar, multilayer structure suitable for integration.
• It provides a viable solution for long-distance, non-contact measurement of electric fields.
• The design can be scaled for reduced size by increasing operating frequency without dielectric loss concerns.