Resonance microwave reflectometry for high-resolution surface imaging

Abstract

Novel high-resolution near field imaging technique based on microwave resonance reflectometry is presented. Two types of microwave resonance probes are considered - a small helix antenna and a resonantly loaded aperture in conductive screen. It is shown that these probes possess the electromagnetic (EM) characteristics essential for high-resolution near field imaging device: (i) they enable very tight near field collimation with full width at half maximum less than λ/10, λ is a wavelength of radiation; (ii) the probes near field coupling to the imaged samples is based on the high-quality resonance energy transmission which allows their operation at very low excitation power level with high receive signal-tonoise ratio. Additionally, the resonance nature of these probes enables accurate microwave spectroscopic characterization of a wide range of dielectric materials. To the best of the authors' knowledge resonance microwave probes of considered types have never been applied to near field imaging before.