Compact Chipless CLAF-SIW Sensor with Integrated Aperture-Coupled Antenna for Measuring Time-varying Electric Field

In this paper, a compact wireless electric field sensor based on a chipless, contactless air-filled substrate-integrated waveguide (CLAF-SIW) resonator integrated with an aperture-coupled microstrip patch antenna is presented. CLAF-SIW technology provides a high Q-factor, enabling wireless far-field interrogation with increased distance. The integrated aperture-coupled antenna provides a compact, thin planar structure. The time variation of the external electric field results in variation of the resonance frequency of the CLAF-SIW sensor which is detected by analyzing the back-scattered ringback signals from the sensor. An experimental setup is developed to perform wireless measurement of a time-varying external electric field. The experiments show that the sensor can measure an external time-varying electric field up to 7 kV/m in the frequency range of 3 Hz to 1 kHz. The measured sensitivity of the CLAF-SIW sensor and the interrogation distance are 342 (Hz)/ (V/m) and 55 cm, respectively.