Figure 2
Multipole modes excitation in spoof local surface plasmons (S-LSPs) resonators excited by a normal incidence plane wave. (a) The schematics of the X-band frequency selective surface consist of spoof local surface plasmons (S-LSPs) resonators with the periodicity of P = 15 mm at normal incidence. The incidence wave vector lies along the z direction, with the electric field along the y direction. (b) Simulated and measured transmission spectra of the X-band frequency selective surface. (The simulated structure is infinite in x and y direction; the measured structure is a 225 units array with 15 rows and 15 lines in x and y direction). (c) The simulated near field modes patterns of vertical electric field (Ez) on the plane 0.5 mm above the S-LSPs: (M1) dipole mode at 8.85 GHz, (\({{\rm{M}}}_{3}^{{\rm{a}}}\), \({{\rm{M}}}_{3}^{{\rm{b}}}\) and \({{\rm{M}}}_{3}^{{\rm{c}}}\)) the transforming hexapole modes at 9 GHz, 10 GHz and 11 GHz, respectively, (M3) the hexapole mode at 11.77 GHz.
