Left-handed metastructures with selective frequency transmission window for gigahertz shielding applications

Abstract

Experimental evidence of left-handed properties of the Fe-, CoFe-, and Co-based glass-covered amorphous microwires in free standing systems is demonstrated. A new broadband frequency shielding metastructure with selective transmission frequency in the microwave range is presented. The X-band microwave-guide and the free-space methods were used as experimental techniques in the frequency range from 1 to 12 GHz. The X-band experimental results show that the mixed metastructure presents left-handed behavior between 8.5 and 10.5 GHz. The mixed metastructure for large areas presents broadband frequency domains, with left-handed properties between 6.5 and 10.5 GHz (the sum of intrinsic ferromagnetic and antiferromagnetic resonance frequencies domains of individual microwires) and a transmission window between 7.6 and 10.5 GHz. Double negative characteristics of the metastructures are in agreement with the computed results calculated based on Landau–Lifshitz–Gilbert equations and Nicolson-Ross-Weir analytical method.

Vertical interface augmented tunability of scattering spectra in ferromagnetic microwire/silicone rubber metacomposites

“…Metacomposites containing ferromagnetic glass-coated microwires have attracted much attention owing to their multiple emerging properties and associated broad range of applications such as structural health monitoring, microwave absorption and electromagnetic shielding [1][2][3][4][5]. Strong responses from the microwires to the incident electromagnetic wave are possible due to their distinguished giant magneto-and stress-impedance effects, soft magnetic character and emerging double-negative (DNG) properties arising from their arrangement in the matrix [4,[6][7][8]. Moreover, it is possible to further tune the scattering spectra of microwire metacomposites through external stimuli such as magnetic field, temperature or stress.…”

Left-handed properties dependence versus the interwire distance in Fe-based microwires metastructures

“…A microwire length of L = 8 mm was used. The interwire distance, d, was chosen so that the dielectric negative frequency domain would be superimposed over the negative magnetic frequency domain due to plasma frequencies values, 8 The left-handed characteristics of the metastructures were determined by measuring the reflection, S 11 (dB), and the transmission, S 21 (dB), coefficients by using a WR90 type X-band microwave guide connected to a PNA L5230 Agilent Vector Network Analyzer (VNA) after a SOLT (short-openload-through) calibration of the set-up, 3 in the frequency range 8.2÷12 GHz. The magnetic field, H, applied parallel with the long axis of the microwires (as shown in Figure 1) is ranging from 0 to 32 kA/m.…”

“…[1][2][3] The properties of such metastructures are dependent on their geometrical parameters and also on the intrinsic properties of the used microwires, offering flexibility for achieving different engineering requirements. [4][5][6] A specific parallel arrangement of GCAWs in metastructures present a plasma-behavior in the presence of incident electromagnetic field and, consequently, negative dielectric characteristics of metastructures are obtained, 7,8 while the ferromagnetic resonance of the GCAWs leads to a negative magnetic response.…”

Dual band low loss metamaterial structure at millimetre wave band

“…The base theory of these materials is introduced by Russian scientist veslago in 1967 [3]. The unusual electromagnetic characteristics of the MMs enable a lot of practical applications such as using the MMs for shielding, clocking, transfer power, enhance antenna performance, superlens, resolution imaging enhancers [4][5][6][7][8][9].…”