Transmission Of Frequency Selective Surface Research Articles

A Frequency-Selective Surface Rasorber Based on Four Functional Layers

In this article, a frequency-selective surface (FSS) rasorber based on four metallic FSS functional layers is proposed. The rasorber consists of two metallic FSS absorption layers, two metallic FSS transmission layers, and four corresponding dielectric isolation layers. The top absorption layer and third absorption layer are applied to generate a wide absorption band at high frequency and low frequency, respectively. The second and bottom transmission layers are adopted to generate a low-pass transmission band and bandpass transmission band, respectively. The multilayer structure of the rasorber guarantees the great span, broad bandwidth, and stable scattering characteristics. Moreover, we adopt the equivalent circuit model (ECM), surface current distribution, and loss distribution to comprehend the physical mechanism of the rasorber. The simulated results show that the transmission is -0.67 dB at 6.5 GHz, and the reflection below -10 dB ranges 1.5-4.6 and 9.2-13.7 GHz. To validate our design, we fabricated and measured the prototypes, and the measurement results show reasonable agreement with the simulated results.

An Infrared Frequency Selective Surface with Dual Stopband

In order to get the low transmission rate in both mid infrared atmospheric window and far infrared atmospheric window, an infrared frequency selective surface composed of two layers based on hexagonal ring structure was designed. Simulation analysis using CST electromagnetic software shown that the frequency selective surface had two stopbands in both 3μm~5μm and 8μm~15μm regions, of which the average transmittance is lower than 2.5%. Therefore, this frequency selective surface realized two stopbands in infrared wavebands; This paper analyzed the filtering mechanism of the frequency selective surface based on the effective medium theory. In the end, this paper researched the effect of electromagnetic wave polarization mode, incident angle and dielectric layer thickness on the transmission properties of the frequency selective surface. The results revealed that the transmission of frequency selective surface is insensitive to polarization mode and incident angle, while the dielectric layer thickness is an important factor to the transmittance of frequency selective surface.

Design and analysis of infrared frequency selective surface with dual-stopband

A dual-band frequency selective surface (FSS) with double screen was designed to cover the mid-infrared atmospheric window (3 μm~5 μm) and the far-infrared atmospheric window (8 μm~14 μm). This structure is com-posed of hexagonal metallic mesh and hexagonal resonant ring array. Simulation results show that the average transmission of FSS in atmospheric window is lower than 5%, and this structure is insensitive to the incident angle. The effect of the parameters on transmission properties was analyzed. The results show that adjusting the size of hexagonal ring structure can effectively adjust the -10 dB stopband bandwidth in 3 μm~5 μm, and increasing the size of metallic mesh can move the stopband in 8 μm~14 μm to long wave direction.

Significant Factors in the Inkjet Manufacture of Frequency-Selective Surfaces

Additive fabrication of electromagnetic structures by inkjet printing technology is both cost effective and compatible with a wide range of environmentally friendly substrates, enabling the fabrication of frequency-selective surface (FSS) arrays with line dimensions less than 0.1 mm, which is difficult to achieve with conventional subtractive techniques. Several approaches, such as savings in ink by depositing it at the edges of dipole elements where the surface current tends to maximize, have been investigated in order to produce low-cost frequency-selective panels with acceptable level of isolation. The FSS transmission characteristics were improved by jetting multiple ink layers on the whole elements and at the edges. The electrical resistance of various arrays have been measured and analyzed and has been used to assess the performances of the FSS.

Experimental characterization of FSS for WLAN applications with low‐cost UWB elliptical microstrip monopole antennas

ABSTRACTIn this work, we propose an elliptical microstrip monopole antenna with ultrawideband (UWB) characteristics to be applied in low cost measurements of frequency selective surfaces (FSSs). The −10‐dB impedance bandwidth of the elliptical antenna is 1.0–13.5 GHz, which is about 172% broader. To demonstrate the antenna application in FSS measurements, we also propose a dual‐band band‐stop FSS with metallic patches based on teragon fractal geometry designed to reject wireless local area network signals. Theoretical analysis of the elliptical monopole and FSS is done using Ansoft HFSS and Ansoft DesignerTM commercial softwares, respectively. Prototypes of designed antenna and FSS were built and measured. Through the use of UWB monopole antennas, we obtained an excellent agreement between simulated and measured FSS transmission coefficients. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1331–1333, 2014

A Third-Order Bandpass Frequency Selective Surface With a Tunable Transmission Null

We present the design and analysis of a frequency selective surface (FSS) capable of providing a third-order bandpass response. The transfer function of the proposed FSS has a transmission null, the frequency of which can be tuned to suppress strong interference signals with frequencies close to or within the main transmission band. The principles of operation of the device are presented along with an approximate analytical procedure for synthesizing the desired FSS response. Two prototypes are fabricated and characterized using a free-space measurement setup and the FSS's different modes of operation are experimentally demonstrated. Finally, the tuning performance of the FSS's transmission null is experimentally demonstrated in a WR-90 waveguide environment.

Multiband fractal cross dipole frequency selective surface

Fractal structures has self-similar properties so that they can be applied in the field of frequency selective surface (FSS) as unit cell and the fractal FSS has the nature of simple ,multi-band characteristics on single layer FSS which can be used as spatial pass filters for the incident angle, polarization and the frequency of the electromagnetic wave. Take fractal cross dipole as example, which we can obtain by recursive algorithm and iterative technique, this work gives the expressions of the fractal elements’ geometry and then characterizes the FSS transmission response by the electric field integral equation for the current distribution on the single FSS screen derived from the Floquet's periodic theory unden impedance boundary condition. Genetic algorithm was applied to globally optimize the structure parameters in order to get the design of the double resonant FSS. Finally, FSS sample was prepared by optical lithography and measured in the anechoic chamber. Experimental results show good agreement with the calculations we made for the design of FSS with resonant frequencies 9.2 GHz and 29.4 GHz, which was what we expected from the periodic method of moment.

Effects of manufacturing artifacts on infrared filter performance

AbstractThe effect of manufacturing artifacts on the performance of infrared frequency selective surfaces (FSS) is investigated in this article. For cross‐slot structures, these artifacts include slot length variation, slot width variation, the variation of spacing among elements, structural center broadening, and slot edge rounding. Quantitative measures of these effects on FSS transmission spectrum are obtained via a three‐dimensional (3D) periodic finite‐difference time‐domain method. The study shows that peak transmission intensity, resonant wavelength, and half‐max bandwidth of the transmission spectrum can be significantly affected by these manufacturing artifacts. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1749–1754, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21752