A Compact Frequency Selective Surface With Stable Response for WLAN Applications
TL;DR: In this paper, a compact frequency selective surface (FSS) composed of a modified swastika unit cell having the smallest dimension of 7 × 7 mm2 is proposed, aimed at the rejection of 5 GHz WLAN band.
Abstract: In this letter, a compact frequency selective surface (FSS) composed of a modified swastika unit cell having the smallest dimension of 7 × 7 mm2 is proposed. The design is aimed at the rejection of 5-GHz WLAN band. The unit-cell geometry resembles the shape of crossed dipoles to achieve compactness. The proposed FSS provides 400 MHz bandwidth with 20 dB insertion loss. The proposed design holds a stable response for TE and TM modes of polarization as well as oblique incidence angles, thus ensuring polarization and angular independent operation. The simulated results are validated with measured results obtained from the fabricated FSS.
Citations
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TL;DR: In this article, a review of recent developments in the field of frequency selective surface (FSS)-based advanced electromagnetic (EM) structures is presented, which is a type of filter consisting of an array of periodic metallic patches or apertures on a dielectric substrate.
134 citations
TL;DR: In this article, an anchor-shaped loop unit-cell structure for compact frequency selective surfaces (FSSs) with dual-bandstop behavior in two wireless local area network (WLAN) frequencies 2.4 and 5.0 GHz is proposed.
Abstract: In this letter, we propose an anchor-shaped loop unit-cell structure for compact frequency selective surfaces (FSSs) with dual-bandstop behavior in two wireless local area network (WLAN) frequencies 2.4 and 5.0 GHz. The proposed FSS possesses 230- and 300-MHz bandwidths with insertion loss less than ${-}$ 20 dB around the two central operating frequencies 2.4 and 5.0 GHz, respectively. In addition, the FSS exhibits excellent miniaturization with 0.065 $\lambda \times 0.076 \lambda$ unit cells, where $\lambda$ represents the free-space wavelength. Furthermore, the unit-cell structure provides a stable performance for both TE- and TM- polarizations under incident angles 0 $^{\circ}$ –60 $^{\circ}$ . A prototype of the proposed FSS is fabricated and measured. Good agreement between the simulated and measured results is obtained.
110 citations
Cites background from "A Compact Frequency Selective Surfa..."
...0 GHz in [7] were obtained, respectively....
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...In recent years, with the rapid development of wireless communication technology, the use of FSSs in telecommunication, wireless security, and interference mitigation between adjacent wireless local area networks (WLANs) have been researched extensively [3]–[7]....
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TL;DR: In this article, a band-stop frequency selective surface (FSS) is proposed to provide effective shielding in X-band, with attenuation of at least 56 dB, and the proposed FSS provides 3-dB fractional bandwidth of 48% which is necessary to cover Xband.
Abstract: In this paper, a novel and miniaturized band-stop frequency selective surface (FSS) is presented. This FSS provides effective shielding in X-band, with attenuation of at least 56 dB. The proposed FSS provides 3-dB fractional bandwidth of 48% which is necessary to cover X-band. Moreover, the proposed design is polarization independent as it provides a stable frequency response at normal and oblique angles of incidences for both perpendicular TE and parallel TM wave modes. The copolarized and cross-polarized scattering parameter $S_{21}$ is analyzed at the selected band-stop/notch frequencies. More importantly, the proposed FSS is suitable for conformal applications and hence finds wider employability. A prototype of the proposed FSS is fabricated and tested. The measured results are in good agreement with the simulated results.
93 citations
Cites background from "A Compact Frequency Selective Surfa..."
...In [27], [28], FSSs are proposed with band-pass and band-stop characteristics for WLAN applications....
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...However, in most of the applications, the function of the FSS is limited to narrow bandwidth [18], [19], [21], [22], [28]....
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TL;DR: In this article, the frequency selective surface (FSS) properties of a uniplanar electromagnetic band-gap unit cell are studied and a 13 × 13 array of these unit cells is used as a superstrate at a distance ≈ 0.5λ from the center frequency of the FSS passband.
Abstract: In this letter, frequency selective surface (FSS) properties of a uniplanar electromagnetic band-gap (EBG) unit cell are studied. The unit cell consists of meander-line inductor and interdigital capacitors on one side of a substrate. Simulation results indicate that the unit cell exhibits passband characteristics centered at 10.04 GHz. FSS property of the structure is verified by measurement using X-band waveguides. The measured results show passband characteristics at 9.45 GHz. A 13 × 13 array of these unit cells (FSS screen) is used as a superstrate at a distance ≈ 0.5λ
0
over a patch antenna operating at 10.8 GHz, offset from center frequency of the FSS passband. Directivity improvement of 6.95 dB is observed along 0° in the measurements of patch antenna with FSS superstrate as compared to the patch antenna without superstrate.
90 citations
Cites background from "A Compact Frequency Selective Surfa..."
...F REQUENCY selective surfaces (FSSs) are resonant structures having either stopband [1]–[5] or passband [6]–[11] performance, due to which they are widely used as radomes, spatial filters, electromagnetic absorbers, and shielding structures....
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TL;DR: In this paper, the angular independent dual-band FSS with closely spaced response is discussed, and the proposed single layer FSS comprises of unit cell resembling crooked cross geometry convoluted and branched to provide dual resonant paths.
Abstract: A novel angular independent dual-band FSS with closely spaced response is discussed in this letter. The proposed single layer FSS comprises of unit cell resembling crooked cross geometry convoluted and branched to provide dual resonant paths. The FSS functioning as a band stop filter at 2.54 and 3.54 GHz works as a shielding component for S band operation. The unit cell size of the proposed FSS is $0.088 \lambda \times 0.088 \lambda$ where $\lambda$ corresponds to the wavelength of the first resonant frequency. Both the bands are closely spaced providing the frequency ratio of upper to the lower resonant frequency value of 1.39. Additionally, the proposed dual-band FSS is symmetrical in nature, thereby providing identical stop-band response for both TE and TM operation modes. It also exhibits highly stable angular stability. Prototype of the proposed FSS is fabricated and its simulated results are compared with the experimental results.
61 citations
Cites background or methods from "A Compact Frequency Selective Surfa..."
...Dual-band FSSs implementing periodic cell perturbation technique [13] and using concentric square elements with two different slot sizes [14] are...
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...It is a single layer FSS resembling the shape of the conventional crooked cross design [14], modified by convoluting the arms and to branch out for dual-band operation....
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...Presence of minor deviations in the experimental result can be attributed to the lossy FR4 substrate used for fabrication, and also due to edge reflections and scattering of the EM waves encountered during the measurement [14]....
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...Many techniques are followed to realize the dual frequency response FSS using miniaturized unit cells [4]–[14]....
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References
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Book•
26 Apr 2000
TL;DR: In this article, the authors present a comparison of band-pass and Dichroic filter designs for one and two-dimensional periodic structures, and present an overview of the current state-of-the-art.
Abstract: General Overview. Element Types: A Comparison. Evaluating Periodic Structures: An Overview. Spectral Expansion of One- and Two-Dimensional Periodic Structures. Dipole Arrays in a Stratified Medium. Slot Arrays in a Stratified Medium. Band-Pass Filter Designs: The Hybrid Radome. Band-Stop and Dichroic Filter Designs. Jaumann and Circuit Analog Absorbers. Power Handling of Periodic Surfaces. Concluding Remarks and Future Trends. Appendices. References. Index.
3,896 citations
TL;DR: In this paper, a bandpass frequency selective surface (FSS) is proposed, which is made up of periodic array of metallic patches separated by thin air-gaps backed by a wire mesh having the same periodicity.
Abstract: We demonstrate a new class of bandpass frequency selective surface (FSS), the building block of which, unlike the traditional FSSs, makes use of resonant dipole and slot structures that have dimensions much smaller than the operating wavelength. This design allows localization of bandpass characteristics to within a small area on the surface which in turn facilitates flexible spatial filtering for an arbitrary wave phasefront. The proposed FSS is made up of periodic array of metallic patches separated by thin air-gaps backed by a wire mesh having the same periodicity (Ltlambda). The array of metallic patches constitute a capacitive surface and the wire mesh a coupled inductive surface, which together act as a resonant structure in the path of an incident plane wave. Like traditional FSSs, the capacitive and inductive surfaces of the proposed FSS can easily be fabricated using printed circuit technology on both sides of microwave substrates. It is shown that by cascading such bandpass surfaces in a proper fashion, any arbitrary multipole filter or non-commensurate multiband response can be obtained. The frequency response of the proposed miniaturized-element frequency selective surface (MEFSS) is demonstrated for various incident angles and it is shown that one-pole designs are less sensitive than two-pole designs to the angle of incidence. Dual band designs are also possible based on two-pole designs, but are more sensitive to incident angle than single band designs because of their larger (in terms of wavelengths) spacing. Prototypes of single-pole and dual-pole MEFSSs are fabricated and tested in a waveguide environment at X-band frequencies and excellent agreements between the measured and simulated results are demonstrated
544 citations
"A Compact Frequency Selective Surfa..." refers background in this paper
...FSSs made of miniaturized elements are also discussed in [10] and [11]....
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TL;DR: In this paper, a single-layer substrate frequency selective surface (FSS) made of miniaturized elements is proposed, with two controllable passbands obtained, each FSS element consists of a loop wire on the top metal layer and its complementary pattern etched at the bottom one, which provides two transmission poles separated by a transmission zero.
Abstract: A single-layer substrate frequency selective surface (FSS) made of miniaturized elements is proposed, with two controllable passbands obtained. Each FSS element consists of a loop wire on the top metal layer and its complementary pattern etched at the bottom one, which provides two transmission poles separated by a transmission zero. An equivalent circuit model is given for predicting the characteristics of the designed FSS, and a good agreement between the simulated and measured transmission coefficients is obtained. Furthermore, the cases of oblique wave incidence and cascading FSSs are also measured and examined.
164 citations
"A Compact Frequency Selective Surfa..." refers background in this paper
...FSSs made of miniaturized elements are also discussed in [10] and [11]....
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TL;DR: In this paper, a novel miniaturized periodic element for constructing a bandpass frequency selective surface (FSS) is proposed, which has better miniaturization performance with the dimension of a unit cell only 0.061 λ × 0.61, where λ represents the wavelength of the resonant frequency.
Abstract: In this letter, a novel miniaturized periodic element for constructing a bandpass frequency selective surface (FSS) is proposed. Compared to previous miniaturized structures, the FSS proposed has better miniaturization performance with the dimension of a unit cell only 0.061 λ × 0.061 λ , where λ represents the wavelength of the resonant frequency. Moreover, the miniaturization characteristic is stable with respect to different polarizations and incident angles of the waves illuminating. Both simulation and measurement are taken, and the results obtained demonstrate the claimed performance.
102 citations
"A Compact Frequency Selective Surfa..." refers methods in this paper
...Spiral elements with different combinations are brought together for miniaturized passband FSS in [7], and in [8], passband FSS with excellent miniaturization is achieved....
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TL;DR: In this article, a miniaturized periodic element was proposed for constructing a band-pass frequency selective surface (FSS) that demonstrates an excellent resonance stability performance with respect to different polarizations and incidence angles.
Abstract: In this letter, we propose a miniaturized periodic element for constructing a band-pass frequency selective surface (FSS) that demonstrates an excellent resonance stability performance with respect to different polarizations and incidence angles. In contrast to traditional periodic elements with sizes comparable to a half of the wavelength at the resonant frequency, the size of the proposed element is reduced highly to only a tenth-wavelength. We created and examined a prototype of the miniaturized-element FSS. Both the simulated and measured results obtained demonstrate the claimed performance.
91 citations
"A Compact Frequency Selective Surfa..." refers methods in this paper
...Spiral elements with different combinations are brought together for miniaturized passband FSS in [7], and in [8], passband FSS with excellent miniaturization is achieved....
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