Fig. 1. Schematic representation of a nonlinear enhanced electromagnetic transmission using a subwavelength metallic aperture with addition of a dielectric meta-atom. (a) Front view (y–z plane) of a subwavelength aperture at the center of a copper plate. (b) Front and (c) sectional views (x–z plane) of the subwavelength aperture with the inserted dielectric meta-atom. Electric field intensity distributions (x–y plane) at the (d) nonresonant frequency (11.5 GHz) and (e) resonant frequency (11.73 GHz) of the meta-atom when the metallic aperture with the added meta-atom is placed within the waveguide and the electromagnetic waves are excited from one of the waveguide ports.

Fig. 2. Principles of the nonlinear enhanced electromagnetic transmission properties of a subwavelength metallic aperture with an added dielectric meta-atom. Transmission coefficients T1, T2, and T3 at incident powers of P1, P2, and P3, respectively.

Fig. 3. (a) Measured and (b) simulated transmission spectra of the single subwavelength metallic aperture and the same aperture with an inserted ceramic meta-atom at incident electromagnetic powers ranging from 0 to 20 dBm.

Fig. 4. Transmission spectra of the subwavelength aperture with the added ceramic meta-atom over the incident power range from 0 to 20 dBm. Enhanced nonlinear transmission is shown at (a) 11.71 GHz, (b) 11.74 GHz, and (c) 11.76 GHz, while linear transmission is shown at (d) 12 GHz. Black lines represent the measured results; red lines represent the simulated results.