Energy-Tunneling Dielectric Sensor Based on Substrate Integrated Waveguides

In this paper, we propose a dielectric sensing device based on a wire-loaded substrate-integrated-waveguide (SIW) structure that supports energy-tunneling phenomenon. The extremely intense electromagnetic fields that are created around the resonant wire can be exploited to design highly sensitive dielectric sensor. We show that by constructing two SIWs connected through a thin metallic wire, fine changes in dielectric constant of solid as well as liquid samples placed at high-energy points can be detected by observing the resonant frequency shifts. When the metallic wire is loaded with extremely small sized (1.9 mm³) solid and liquid samples, the respective resonance shifts of 0.2 and 1 GHz are measured. Based on the proposed SIW tunneling structure, a new class of highly sensitive, low cost, and rugged sensors can be designed that are suitable for biomedical and forensic applications.