Enhanced Transmission Through Single Sub-Wavelength Apertures Using Miniaturized Planar Resonators

An in-plane two-layer meandered wire resonator structure is utilized to enable transmission through a subwavelength aperture. The structure exhibits effectively 100% transmission at approximately 1.94 GHz through a λ 0/33 square aperture. The extremely high Q resonance presents a transmission greater than -10 dB over a bandwidth of 0.007%. A complementary subwavelength resonator is also proposed, which exhibits a narrow band transmission response operating at 1.92 GHz with a fractional bandwidth of 0.04% at an overall electrical size of λ0/43. A good agreement between measured and simulated results is achieved for both designs. The subwavelength structures show a slight sensitivity to fabrication tolerances, but are realizable with modern printed circuit fabrication techniques due to their planar nature.