An experimental concentric near-field plate

Mohammadreza F. Imani, Anthony Grbic

Research output: Contribution to journalArticlepeer-review

20 Scopus citations


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.

Original languageEnglish (US)
Article number5621935
Pages (from-to)3982-3988
Number of pages7
JournalIEEE Transactions on Microwave Theory and Techniques
Issue number12 PART 2
StatePublished - Dec 2010
Externally publishedYes


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

ASJC Scopus subject areas

  • Radiation
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


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