In this letter, we present a theoretical device that can produce electromagnetic near-field patterns with deep subwave-length resolution. The device consists of a single slit in a corrugated metallic surface. The surface exhibits a nonperiodic series of grooves symmetrically positioned about a waveguide-fed slit. A procedure for designing such a device is described in detail. The electromagnetic response of the corrugated surface is shown to be as theoretically predicted, producing a subwavelength focal pattern with a null-to-null beamwidth of λ/10. In addition, the effect of losses on the performance of the device is studied. Finally, it is shown that the device can be impedance-matched to its waveguide feed. Such devices will find use in noncontact sensing and near-field probing applications.
- Corrugated surface
- Diffraction limit
- Near field
ASJC Scopus subject areas
- Electrical and Electronic Engineering