Metamaterial-inspired miniaturized microwave sensing probes

In this paper, two microstrip transmission line based metamaterial structures (sub-wavelength sized resonators) are designed and implemented in near field sensing of dielectric materials. One structure is designed for band-stop and the other for band-pass performance in the X-band region. These resonators load the microstrip lines on both the sides. Resonator on one side is used in interrogation of sample and the other side is used for reference. Upon introduction of sample, the resonance frequency shifts relative to the reference resonance frequency. This approach provides high sensitivity detection with built in reference providing high signal to noise ratio. Fabricated samples were characterized for sensing applications by loading with solid dielectric samples. An array of sensors can be linearly cascaded for high throughput sensing of multiple samples using single input output ports. Details of design, fabrication and measurements are presented in the paper for these two designs.