An Experimental Concentric Near-Field Plate

作者：Imani Mohammadreza F^*; Grbic Anthony

来源：IEEE Transactions on Microwave Theory and Techniques, 2010, 58(12): 3982-3988.

DOI：10.1109/TMTT.2010.2088136

• Electromagnetic (EM) probes
• EM theory
• metamaterial
• near-field imaging
• super resolution techniques

We present a concentrically corrugated near-field plate that can form a subwavelength near-field focal spot. The experimental plate consists of a coaxial aperture surrounded by nonperiodic concentric corrugations. The measured subwavelength patterns are shown to be significantly narrower than those created by a coaxial probe (without corrugations) of similar dimensions. Close agreement between simulated and measurement results is observed. Further, the subwavelength beam emitted by the corrugated near-field plate is shown to be narrower that of the coaxial probe, confirming the superior electromagnetic confinement achieved by the near-field plate over a focal length. Finally, the near-field plate is used to image two sources separated by subwavelength distances. The images obtained using the near-field plate exhibit significantly higher resolution than those obtained using a coaxial probe. The reported near-field plate will find use in near-field probing and microscopy applications.

• 出版日期2010-12