Tunneling of electromagnetic energy through wires in guided media

Tunneling of electromagnetic energy can take place in narrow (sub-wavelength) channels filled with either the epsilon-near-zero materials or resonant wires. Since the tunneling is accompanied by very intense electric fields, the resulting frequency response is highly selective. In this paper, a microstrip bend is studied that supports energy tunneling. It has been shown, through full-wave simulations, that the tunneling mode is highly frequency selective and depends on the wire length and substrate permittivity. Hence very high-Q resonant cavities can be designed that may have potential applications in filtering and sensing applications. The microstrip technology, compared to the rectangular waveguides, is low cost, robust, easily fabricated and suitable for planar integration.