Ohmic loss in frequency-selective surfaces

Abstract

Articles you may be interested inInfrared transparent frequency selective surface based on metallic meshes AIP Advances 4, 027112 (2014); 10.1063/1.4866292 Enhancing and broadening absorption properties of frequency selective surfaces absorbers using FeCoB-based thin filmFrequency selective surfaces as near-infrared electromagnetic filters for thermophotovoltaic spectral controlThe present study was undertaken in order to quantify absorption effects due to ohmic loss in frequency-selective surfaces ͑FSS͒ at infrared frequencies. The structures considered in this work act as electromagnetic filters, and as such, are of interest for use as thermophotovoltaic spectral control devices. For this application, absorption is of primary concern since it leads to reduced filter efficiency. This work focuses on the behavior of single-layer, free-standing FSS arrays comprised of circular apertures ͑holes͒ and circular loop apertures ͑rings͒. Numerical calculations of the transmission, reflection, and absorption characteristics of various arrays were carried out for wavelengths between 1 and 15 m using a commercial finite-element software package. Absorption effects were included using measured optical properties as input parameters to a surface impedance boundary condition. Analytical techniques were then employed to determine the absorption behavior in the static limit. An interesting result of this analysis is the fact that absorption at 15 m is predicted by the finite-element calculations to increase versus aperture radius ͑for fixed aperture separation͒, while in the static limit absorption was found ͑through the use of analytical techniques͒ to decrease. The results of the finite-element calculations were confirmed using another numerical method based on the periodic moment method. We are thus led to the conclusion that the qualitative relationship for absorption versus aperture radius must reverse for some frequency regime yet to be investigated.

A Wide-Band, Polarization-Insensitive and Wide-Angle Terahertz Metamaterial Absorber

“…The dielectric loss of the substrate is minor compared with the metallic absorption. This is different from previous studies on frequency selective surfaces (FSSs) where metallic absorption was relatively insignificant in comparison with dielectric loss of the substrate [21].…”

PMM-GA METHOD TO SYNTHESIZE QUASI-OPTICAL FREQUENCY SELECTIVE SURFACE ON SiO₂ SUBSTRATE

“…There is a slight alteration in TM case, on which the FSS is provide a 3 dB bandwidth of 32 GHz (approx. from 168 GHz to 200 GHz), insertion loss [18,19] of 0.21 dB, and operating frequency of 184.3 GHz, which could be acceptable in practical applications. The frequency response curves of S parameters for full wave at 45 • incidence are reported in Figure 6.…”

A Circuit-Based Model for the Interpretation of Perfect Metamaterial Absorbers

“…Ohmic losses, which come from the currents flowing on an imperfect conductor, are instead increasingly important as the working frequency raises. In THz range, the ohmic resistor is comparable with the dielectric one while in optical regime ohmic losses dominate [36].…”