Design of conformal dual stop band frequency selective surface for microwave applications

Dual stop band frequency selective surface for C and WLAN band applications

This work presents a miniaturized angularly stable frequency selective surface (FSS) on a single layer substrate. Unit cell comprises of convoluted circular rings connected cross dipole and linear arrow headed dipole printed on both sides of the substrate. A closely spaced dual stop band resonances are obtained at 10 and 14.3 GHz with frequency ratio of 1.43. FSS shows a − 10 dB stopband bandwidth (BW) from 7.32 to 11.05 GHz (40.61%) and 12.68 to 15.97 GHz (22.97%) with >30 dB stop band rejection at center frequencies. FSS poses the features of stable performance under change in polarization and angularly stable response up to 60° incident angle. Later the proposed FSS is printed on grounded thick dielectric substrate and it shows broadband reflection type co to cross polarization conversion from 7.2 to 17.32 GHz (82.54%) with polarization conversion ratio >80% and oblique angle stability up to 35°. To the best of authors' knowledge, this is the first time in literature a single unit cell geometry with two different properties, spatial filtering on transmission and polarization conversion on reflection have been designed and analyzed in details. A finite array with size 25 × 25 of the proposed FSS is fabricated and the measured filter response shows a good agreement with simulated performance at normal and oblique incidences. The proposed FSS is used as a reflector of a dual band monopole antenna and the simulation results shows gain improvement of 5.51 and 3.8 dB at the two stopband frequencies.

This paper presents a band-stop frequency selective surface (FSS) design method based on equivalent circuit. This method first constructs a band-stop filter circuit that meets the design goals, and then extracts the corresponding equivalent circuit parameters for rough FSS design. Finally, the original FSS structure is optimized by the full wave method to achieve the design goal. The article gives examples of single stop band FSS and dual stop band FSS, which proves that the method is simple and effective.

This paper presents a dual band and multiple band frequency selective surface (FSS) on energy saving glass (ESG). In this paper, there are two designs that have been presented, namely Design A which is a combination of double strip in vertical and horizontal position and Design B is a combination of double strip in vertical and horizontal position using complementary techniques. Design A and Design B are simulated using CST Microwave Studio software. The simulation process is based on the characteristics of the reflection coefficient (S11) and transmission coefficient (S21) of the FSS. The Design A resonates at two frequencies of 1.75 GHz and 3.4 GHz. The Design B resonates at three frequencies of 0.8 GHz, 1.8GHz and 3.4 GHz.

In this paper, a dual-band band-stop frequency selective surface(FSS) is designed. Structure of the FSS is composed of upper and lower metal patches on a dielectric substrate. The metal patches consist of a square metal strip on one side of the dielectric substrate and a folded ring part on both sides of the dielectric substrate. The dual-band FSS can operate on 1.6 GHz and 2.4 GHz which TE mode bandwidth is 0.1 GHz~0.18GHz and 0.4 GHz~0.68GHz (-15dB stop-band bandwidth), and TM mode bandwidth is 0.04 GHz~0.1GHz and 0.2 GHz~0.4GHz (-15dB stop-band bandwidth), respectively. The whole dimension of miniaturized unit cell of elements is 0.085λ × 0.085λ. The miniaturization element of FSS and stable center frequency is achieved.

Recent progress in microstrip antennas has improved their size and efficiency, particularly in mobile, satellite, and Wi-Max technologies. These enhancements are crucial for advancing wireless communication systems, benefiting applications like telemedicine and GPS technology. The chapter introduces a dual-band unit cell of frequency selective surface (FSS) resonating at 4 GHz and 5.5 GHz, using a combination of I-shaped and modified I-shaped metal strips for dual-band filtering. The research focuses on individual shape analyses and aims to contribute to the development of compact and efficient dual-band FSS designs. The research introduces a dual-band FSS unit cell resonating at 4 GHz and 5.5 GHz, combining I-shaped, H shaped, and modified I-shaped and H shaped metal strips for dual-band filtering. The proposed FSS design, with a 10x10 mm2 unit cell dimension and FR-4 dielectric, exhibits broad frequency band characteristics, aligning well with simulated and measured results.

This paper presents a new design of dual band frequency selective surface (FSS) for band pass microwave transmission application. FSS can be used on energy saving glass to improve the transmission of wireless communication signals through the glass. The microwave signal will be attenuate when propagate throughout the different structure such as building. Therefore, some of the wireless communication system cannot be used in the optimum performance. The aim of this paper is designed, simulated and analyzed the new dual band FSS structure for microwave transmission. This design is based on a quadruple L slot combined with cross slot to produce pass band at 900 MHz and 2.4 GHz. The vertical of pair inverse L slot is used as the band pass for the frequency of 2.4GHz. While, the horizontal of pair inverse L slot is used as the band pass at frequency 900MHz. This design is simulated and analyzed by using Computer Simulation Technology (CST) Microwave Studio (MWS) software. The characteristics of the transmission (S21) and reflection (S11) of the dual band FSS were simulater and analyzed. The bandwidth of the first band is 118.91MHz which covered the frequency range from 833.4MHz until 952.31MHz. Meanwhile, the bandwidth for the second band is 358.84MHz which covered the frequency range from 2.1475GHz until 2.5063GHz. The resonance/center frequency of this design is obtained at 900MHz with a 26.902dB return loss and 2.37GHz with 28.506dB a return loss. This FSS is suitable as microwave filter for GSM900 and WLAN 2.4GHz application.

The design of multiband frequency selective surfaces (FSS) has attracted much attention. It is clear that by arraying dual-band elements it is possible to obtain a dual band FSS. On the other hand, the multiband properties of antennas designed using fractal shapes have been previously demonstrated. It appears a natural choice to explore the feasibility of a dual-band FSS based on fractal elements. A preliminary design of a FSS based on the Sierpinski gasket dipole is presented. The FSS is designed by periodically arraying a two iteration Sierpinski dipole. A fundamental constrain of this approach is the band limitation imposed by the excitation of grating lobes. It is for this reason that the design of a dual band FSS has been addressed, instead of a more general multiband design. The performance of the Sierpinski FSS is compared with a design based on the bow-tie element. It is been shown that it is possible to exploit the multiband properties of fractal antennas to design a dual band FSS.

A single layer tri-band frequency selective surface (FSS) is proposed in this paper. It is composed of two transmission poles and one stop band filter, thus behaving as good isolation between two transmission bands .i.e. C and X-band. The design consists of two square slots with a center square patch and two cross dipole patch diagonally arranged in a two-dimensional unit cell. Two band pass filter is at 6.04 GHz and 9.60 GHz resonant frequency with a band width of 0.89 GHz and 0.87 GHz respectively. One stop band filter at 7.6 GHz resonant frequency in between these C-band and X-band play an important role for the good isolation for wireless communication. The size of unit cell FSS is 0.40&#x03BB;<inf>0</inf>&#x00D7;0.40&#x03BB;<inf>0</inf> and thickness of 0.016&#x03BB;<inf>0</inf>, where &#x03BB;<inf>0</inf> is the first lower resonant frequency. Both pass band resonant frequencies are spaced with a good shielding providing the frequency ratio of 1.57.

The paper proposes a simple band stop frequency selective surface (FSS) design method based on spoof surface plasmon polaritons (spoof-SPPs). The novel FSS design is obtained by combing three-dimension (3-D) FSS and ultra-thin periodic corrugated metallic strip which supports spoof-SPPs. By placing electric-LC (ELC) resonators on the FSS surface at the bottom centre of the corrugated strip, the tight coupling occurs and we show that the SPP modes are rejected near the resonance frequencies of ELC resonators. The steep roll-off at both sides of the stopband can be demonstrated by the ELC resonators, which can find potential applications in wideband antenna radome. In addition, the 3-D FSS shows relatively stable performance with different oblique incidence angles.

In this work, a highly directional ultra-wideband (UWB) microstrip patch antenna as a single-element is suggested. The proposed antenna’s gain is enhanced with a novel dual-band frequency selective surface (FSS) placed beneath it. The FSS design has a hexagonal structure with meander line inductances and a capacitance-like structure connecting all of the corners to the middle. There is no metallic layer on the other side of the substrate, which shows transmission zeros at 4.95 GHz and 12.7 GHz, and a modified U-shaped monopole antenna is developed. First, the performance characteristics of the antenna and FSS are analyzed from the simulation results, and they are validated experimentally after fabrication, followed by measurement. The compact configuration comprises an antenna loaded with the proposed FSS results S11 less than -10 dB from 3.15 GHz to 22.65 GHz, covering the UWB band together with the X, Ku-band with a bandwidth of 19.5 GHz (151.16% FBW). The antenna’s overall physical dimensions would be 38.8 mm×38.8 mm×25.2 mm (0.407λo×0.407λo×0.265λo), with λo denoting the lowest frequency’s free-space wavelength. The FSS loading results in a 9.9 dBi maximum gain at 10 GHz. The antenna’s small size increases bandwidth, and its high peak gain makes it ideal for use in real-time applications.

The design FSS structure consists of square Frequency Selective Surface (FSS) structures placed on the FR4 and glass. The circular and square slot is added on the FSS to design and simulate by using the CST Microwave Studio software for 2.4 GHz and 5.2GHz based on industrial, scientific and medical bands (ISM) standard. The reflection (S11) and transmission (S21) of the design FSS structure is analyzed based on the six types of configuration that have been set up. The hybrid material (FR4+glass) affects the transmission and reflection of the FSS. The highest efficiency for 2.4 GHz and 5.2 GHz are 73% and 89% respectively by using configuration 2.

A novel double layer Dual Band Frequency Selective Surface (FSS)with miniaturized element is presented, in which each periodic cell consists of parallel metallic patch of two different sizes. The FSS with such structure is designed, The simulated results show that the FSS dimension is miniaturized to 0.06 λ (λ refers to the resonant wavelength of 2GHz). In addition, it also has good stability to oblique incidence waves for both TE and TM polarization, and there is no other resonance frequency up to 10 GHz. The influence of dimension parameters on FSS performances has been investigated. Then, dual-band FSS operated at 2GHz and 3.45GHz is designed. Simulated results indicate that the miniaturized FSS also provides good transmission response.

This work presents the design of a dual-band frequency selective surface (FSS) which works as a bandpass filter in the 28 GHz and 38 GHz bands. The proposed FSS is a single layer, easy to fabricate structure and consists of non-uniform unit cells arranged in a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2\times 2$</tex> grid. Furthermore, the proposed FSS is compact and can be placed at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\lambda/21$</tex> distance from the antenna. The design of FSS is validated by using it as a superstrate for two microstrip patch antennas operating at 28 GHz and 39 GHz, and it is demonstrated that the antennas maintain their radiation characteristics, even with the FSS located at sub-wavelength heights over the antennas. With a slim design, the FSS can be employed as a cover for the antenna of 5G mobile terminals operating in the millimeter-wave bands.

This paper proposes a frequency selective surface (FSS) design with two transmission bands which operate at 4.86~7.43GHz and 10.69~12.69GHz, respectively. To exhibit the performance of the proposed FSS model we also make an analysis by equivalent circuit method (ECM). We illustrate the relationship between the FSS structure and the equivalent circuit. There is a good matching from the frequency response of equivalent circuit and the S12 parameters of FSS structure. Finally we use the surface current distribution to make a more detailed description of the characteristics of the frequency selective surface.