- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
UWB Dual-polarized Dipole Array with Dielectric and FSS Superstrate and 65o Scanning
摘要： We report the design of an ultra‐wideband, dual‐polarized, tightly coupled dipole array (TCDA) with an integrated balun for wide angle scanning. A dual‐pol dipole design enables massive bandwidth, large scanning volume, and high polarization purity, concurrently. To achieve wide angle impedance matching without exciting surface waves, two types of superstrates are evaluated on a finite array: 1) dielectric superstrate and 2) novel planar frequency selective surface (FSS). The latter architecture is capable of scanning 70° in E Plane and 65° in H Plane and shows, on average, 5° scanning improvement to the former. The impedance bandwidth is 5.25:1 (0.8‐4.2 GHz) at the broadside (VSWR<2). The bandwidth reduces to 4.3:1 (0.9‐3.9 GHz) when maximum scanning angle or θmax increases to 65° for the H plane and 70° for the E plane (VSWR < 3.2). The proposed array is a great candidate for wide‐angle wide‐band scanning applications covering the entire L and S bands.
关键词： dielectric superstrate,FSS,wide angle scanning,TCDA,Ultra-wideband,frequency selective surface,dual-polarized,tightly coupled dipole array,integrated balun
更新于2025-09-10 09:29:36
-
DUAL-BAND COMPOSITE WIDEBAND ABSORBING MATERIAL FOR BROADBAND ANTENNA IN-BAND RADAR CROSS SECTION REDUCTION
摘要： A composite wideband absorbing material (WAM) covering dual bands is designed, to reduce the in-band radar cross section (RCS) for broadband antenna in this paper. The upper layer is a traditional absorber while the lower one is a dual-band frequency selective surface (FSS), which is formed by a square ring and an improved Jerusalem cross structure. The absorbing band has been broadened to 112% compared with the magnetic sheet without FSS. Over C and X bands, the absorption rate is over 90%. By using the FSS-based WAM as the ground plane of a Vivaldi antenna, substantial RCS reduction is obtained from 2–18 GHz. Moreover, the RCS is reduced remarkably over ?80?–80? incident angles except for minority angles, with the radiation performance preserved at the same time. The experimental results are in good agreement with the simulated ones.
关键词： Vivaldi antenna,frequency selective surface,radar cross section reduction,dual-band,composite wideband absorbing material
更新于2025-09-10 09:29:36
-
Spurious-Free Dual-Band Bandpass Frequency-Selective Surfaces With Large Band Ratio
摘要： Frequency-selective surfaces (FSSs) are widely employed in antenna’s radar cross section (RCS) reduction, which plays a key role in improving survivability and penetration ability of future military systems. In practical, dual-band bandpass FSSs with large band ratio (BR) are urgently needed for some military equipment, such as homing head, that can detect both middle and far range targets. In this paper, a novel method for designing dual-band bandpass FSS with large BR is proposed. The method can provide a large BR response, by utilizing a spurious-free structure and combing resonant and non-resonant elements. Detailed analysis is presented with the aid of equivalent circuit model (ECM) as well as closed-form equations to reveal the operating mechanism. A design example is simulated, fabricated and then measured. Two excellent passbands are obtained with a large BR value of 15.3 in experiment. Moreover, a -10 dB fractional bandwidth (FBW) of 164.3% is realized from 1.31 GHz to 13.35 GHz, without observing any spurious transmission windows. In conclusion, our proposed method fills the gap of the existing dual-band FSSs to obtain a large BR value of more than 6.0 and could be a good guidance for designing future multi-band FSSs.
关键词： frequency selective surface,spurious-free structure,Dual-band response
更新于2025-09-10 09:29:36
-
Extremely low-profile second-order bandpass frequency selective surface using third harmonics of resonant elements
摘要： In high-order (N > 1) frequency selective surfaces (FSSs), the surfaces are usually cascaded vertically and separated by a dielectric substrate to achieve desired responses. The dielectric substrate thickness is a critical parameter in designing such structures. It is usually high for most traditional designs. In this article, we present a novel approach for designing extremely low-profile high-order bandpass FSSs. The structure is built by using the coupling of the third harmonics instead of the fundamentals of the resonators to achieve a bandpass response. By using the proposed design method, the coupling between the third harmonics can be very weak with a very thin substrate, and a flat response can be achieved. The thickness of the structure is reduced to one third in term of wavelength when compared with the structure using the fundamental mode. The overall thickness of a second-order FSS can be reduced to λ/75, where λ is the free space wavelength. A prototype of the proposed bandpass FSS is designed, fabricated, and experimentally characterized. The measurement results of this device show a very good and stable frequency response with respect to the angle of incidence up to (cid:1)45(cid:3) as predicted.
关键词： third harmonics,low profile,frequency selective surface,second order,Bandpass FSS
更新于2025-09-09 09:28:46
-
[IEEE 2018 12th International Conference on Communications (COMM) - Bucharest (2018.6.14-2018.6.16)] 2018 International Conference on Communications (COMM) - Applications of a Frequency Selective Surface Based on a Combination of a Jerusalem Cross and a Circular Ring
摘要： Screening applications of a frequency selective surface (FSS) built on a FR4 substrate with two metal periodic patterns are reported. The square shaped unit cell contains a Jerusalem Cross (Jcross) metal pattern on one face and a circular ring one on the other. Broadband, X band and WLAN filters are proposed and assessed for TE and TM plane wave incidence up to an angle of 45o. The operation of the FSS is demonstrated by computer simulation. Two commercial solvers are used to verify the consistency of the results.
关键词： periodic structures,electromagnetic screening,filtering,Frequency Selective Surface
更新于2025-09-09 09:28:46
-
DESIGN AND ANALYSIS OF A CONTROLLABLE MINIATURIZED TRI-BAND FREQUENCY SELECTIVE SURFACE
摘要： A novel miniaturized combined-element frequency selective surface (CEFSS) with simple design process is proposed for multiband applications. In this article, complementary meandered structures and complementary grid structures are combined to realize controllable tri-band characteristics, which allow the designed FSS to transmit different frequency signals at 3.3, 4.5 and 5.4 GHz while reflecting signals at 4.0 and 4.9 GHz. The miniaturized combined-element FSS in this paper has the advantage of smaller size comparing to traditional tri-band FSSs due to the use of meandered structures, which contributes to its independence of both angle and polarization. The associated equivalent circuit is provided to analyze its transmission characteristics. Furthermore, the performances of the proposed structure are evaluated by simulation and measurement, and they agree well.
关键词： complementary grid structures,complementary meandered structures,combined-element,miniaturized,tri-band,Frequency selective surface (FSS)
更新于2025-09-09 09:28:46
-
A MINIATURIZED BANDPASS FREQUENCY SELECTIVE SURFACE WITH HIGH SELECTIVITY BASE ON SLOT COUPLING
摘要： A Ku-band bandpass frequency selective surface (FSS) with high selectivity and miniaturization is proposed in this paper. We use two metallic strips and one slot to design the frequency selective surface structure which contains both electrical and magnetic couplings. A metallic via is introduced in the FSS element for miniaturization. With the via inserted at the end of the metallic strip, the FSS unit size is reduced to half compared to that without via inserted. To investigate the operating principle of the slot-coupled FSS, an equivalent-circuit model is given and analysed using the odd- and even-mode method. The constructed out-of-phase signal path causes two transmission zeros (TZs) near the skirts of the narrow pass band, thereby enhancing the selectivity. A prototype of the proposed FSS operating at 16 GHz is fabricated and measured. The measured results agree well with the full-wave and circuit simulation results, thus verifying the FSS design.
关键词： slot coupling,Ku-band,bandpass frequency selective surface,metallic via,high selectivity,equivalent-circuit model,transmission zeros,miniaturization
更新于2025-09-09 09:28:46
-
Multiband FSS with Fractal Characteristic Based on Jerusalem Cross Geometry
摘要： This paper proposes a new Frequency Selective Surface (FSS) with modifications on the Jerusalem Cross (JC) geometry to provide a multiband response. Fractal levels are created by introducing concentric self-similar JC copies in the original unit cell. This modification results in new dipoles at the structure which allows for the appearance of new bands proportional to these diploles’ lengths, while maintaining total unit cell size. Three fractal levels of the JC FSS are studied in this paper, and third level presents five resonant frequencies which are f1=1.78 GHz, f2=6.42 GHz, f3=8.69 GHz, f4=10.94 GHz and f5=12.98 GHz. Simulation results for the insertion loss (S21), surface current distribution and measurement results are presented.
关键词： Jerusalem Cross,Frequency Selective Surface,Fractal,Multiband Response
更新于2025-09-09 09:28:46
-
[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Ultra-Wideband Harmonic-Suppressed Bandpass/stop Frequency-Selective Surface Based on L-C Lumped Elements
摘要： Ultra-wideband harmonic rejection bandpass and bandstop frequency-selective surfaces (FSS) based on L-C lumped elements are proposed. The bandpass response is achieved by parallel combination of LC resonant circuit. While is accomplished by series combination. Detailed analysis with the aid of an equivalent circuit models is provided to explain the operating principles and parasitic effects for both FSSs. Bandwidths of 19:1 and 24.5:1 harmonic rejection are achieved between the fundamental frequency and the first harmonic for bandpass and bandstop FSSs, respectively. Controllable resonant frequency and bandwidth are possible by controlling the lumped element’s value. To validate the simulated results, a bandpass FSS prototype is fabricated and measured. It is shown that this methodology is suitable for low frequencies due to the parasitic capacitor associated with the lumped inductor at high frequencies and the change of the component’s value with frequency.
关键词： lumped components,Bandpass frequency-selective surface,Bandstop frequency-selective surface,ultra-wideband harmonic suppression,dual-polarization
更新于2025-09-04 15:30:14
-
A OUTSTANDING MINIATURIZED FREQUENCY SELECTIVE SURFACE BASED ON CONVOLUTED INTERWOVEN ELEMENT
摘要： Based on convoluted interwoven element, a miniaturized frequency selective surface (FSS) with stable band-stop response is proposed in the paper. By extending the four dipoles into the adjacent elements, the equivalent inductance and capacitance are increased, and therefore the proposed FSS realizes promising miniaturization characteristics. The simulation results indicate that the resonant frequency is 1.19 GHz, and the dimension is only 0.027λ0. Compared to traditional crossed elements, the size is reduced by 94.6%. Besides, the FSS has excellent angle-stability under both TE and TM waves. Finally, the proposed FSS is fabricated and measured, and the experiment results prove the satisfactory consistency with the simulation results.
关键词： miniaturized,angle-stability,band-stop response,convoluted interwoven element,frequency selective surface
更新于2025-09-04 15:30:14