The work in this article focuses on developing and improving the performance of new leaky-wave antenna configurations that can be adapted for use in radar systems. The study focused on the W-band, where we demonstrate...The work in this article focuses on developing and improving the performance of new leaky-wave antenna configurations that can be adapted for use in radar systems. The study focused on the W-band, where we demonstrated the possibility of modifying resonant frequencies and reducing the number of patches required. The antenna was designed using HFSS, based on the finite element method. It we designed enabled us to observe the influence of the number of patches on the radiation pattern, and also to achieve low levels of minor’s lobes. and good directivity at the operating frequency. These patches are arranged in the shape of an inverted T. The interest of this study is to meet the requirements of radar antennas dedicated to detection.展开更多
The development of space telecommunications in recent years has necessitated the design and the realization of compact, high-performance equipment operating at increasingly high frequencies. The use of high-precision ...The development of space telecommunications in recent years has necessitated the design and the realization of compact, high-performance equipment operating at increasingly high frequencies. The use of high-precision radars for surveillance, detection and mobile communication systems orients research toward the antennas to electronic sweep. In this article, we present a microstrip leaky-wave antenna with periodic patches. Its design is based on an integral formulation solved by software using HFSS finite elements. A parametric study of this antenna is validated by simulations and compared with other results found in the literature. Analysis of the antenna’s radiation parameters shows that the main beam direction and levels of minor’s lobes can be controlled from these geometrical parameters. The interest of this study is to meet the requirements of antennas dedicated telecommunications systems.展开更多
In this paper, we propose a single-port dual-beam leaky-wave antenna(LWA) in the terahertz(THz) band based on a composite spoof surface plasmon polariton(SSPP) waveguide. The antenna can generate three independent tra...In this paper, we propose a single-port dual-beam leaky-wave antenna(LWA) in the terahertz(THz) band based on a composite spoof surface plasmon polariton(SSPP) waveguide. The antenna can generate three independent transmission channels by exciting two independent modes inherent to hole and groove structures, respectively. By periodic modulation of the hole and groove structures, we achieve dual-beam scanning through a broad radiation angle using only the -1st space harmonics of the two modes, hence avoiding the instability of the -2rd space harmonic. Within the operating frequency range of 0.62—0.85 THz, the gain ranges from 13.5 d Bi to 17 d Bi for the backward beam, and from 6 d Bi to 11.8 d Bi for the forward beam. The antenna can accomplish continuous backward beam through broadside to forward beam scanning with a total scanning range of 116° and an average efficiency of about 92%. The antenna exhibits a great potential in the design of multi-transceiver radar system in the THz band and multi-beam LWAs.展开更多
A simple and efficient design scheme of the continuous long slot leaky-wave antenna is developed. The key steps involved in the scheme are summarized. First, the cut-off frequencies of slot waveguides with different s...A simple and efficient design scheme of the continuous long slot leaky-wave antenna is developed. The key steps involved in the scheme are summarized. First, the cut-off frequencies of slot waveguides with different slot offsets are obtained by 3D finite-difference time-domain （FDTD） method, Second, the attenuation function a^a is estimated by the aperture distribution, and the attenuation function αrs is determined by the slot radiation. Finally, the attenuation function αrs is combined with the attenuation function αrs by the coefficient K. And an example in Ka band is presented. Moreover, the return loss of the E-plane Tee-junction （ET） and the radiation pattern of leaky-wave antenna are simulated. The scheme is verified by comparing with the experimental result.展开更多
A novel leaky-wave antenna(LWA)utilizing spoof surface plasmon polaritons(SSPPs)excitation is proposed with continuous scanning range from endfire to forward.The designed transmission line unit supports two SSPPS mode...A novel leaky-wave antenna(LWA)utilizing spoof surface plasmon polaritons(SSPPs)excitation is proposed with continuous scanning range from endfire to forward.The designed transmission line unit supports two SSPPS modes,of which the 2nd order mode is applied in the design.A novel strategy has been devised to excite the spatial radiation of the-1st order harmonics by arranging periodic counter changed sinusoidal structures on both sides of the SSPPs transmission line.Both full-wave simulation and measurement results show that the proposed LWA presents wide scanning angle from endfire to forward.In the frequency range from 4 GHz to 10 GHz,LWAs achieve scanning from 90°to+20°,covering the entire backward quadrant continuously.展开更多
In this paper, we first propose a metamaterial structure by etching the same two interdigital fingers on the upper ground of quarter mode substrate integrated waveguide（QMSIW）. The simulated results show that the pr...In this paper, we first propose a metamaterial structure by etching the same two interdigital fingers on the upper ground of quarter mode substrate integrated waveguide（QMSIW）. The simulated results show that the proposed QMSIWbased metamaterial has a continuous phase constant changing from negative to positive values within its passband. A periodic leaky-wave antenna（LWA）, which consists of 11 QMSIW-based metamaterial unit cells, is designed, fabricated,and measured. The measured results show that the fabricated antenna achieves a continuous beam scanning property from backward-43° to forward ＋32° over an operating frequencyrange of 8.9 GHz–11.8 GHz with return loss better than 10 d B.The measured antenna gain keeps consistent with the variation of less than 2 d B over the operating frequency range with a maximum gain of 12 d B. Besides, the measured and simulated results are in good agreement with each other, indicating the significance and effectiveness of this method.展开更多
Since leaky-wave antennas(LWAs)have the advantages of high directivity,low loss and structural simplicity,LWAs are very suitable for designing millimeter-wave(mmW)antennas.The purpose of this paper is to review the la...Since leaky-wave antennas(LWAs)have the advantages of high directivity,low loss and structural simplicity,LWAs are very suitable for designing millimeter-wave(mmW)antennas.The purpose of this paper is to review the latest research progress of LWAs for 5G/B5G mobile communication systems.Firstly,the conventional classification and design methods of LWAs are introduced and the effects of the phase constant and attenuation constant on the radiation characteristics are discussed.Then two types of new LWAs for 5G/B5G mobile communication systems including broadband fixed-beam LWAs and frequencyfixed beam-scanning LWAs are summarized.Finally,the challenges and future research directions of LWAs for 5G/B5G mobile communication systems are presented.展开更多
An array of two substrate-integrated waveguide(SIW)periodic leaky-wave antennas(LWAs)with sum and difference beam scanning is proposed for application in target detection and tracking.The array is composed of two peri...An array of two substrate-integrated waveguide(SIW)periodic leaky-wave antennas(LWAs)with sum and difference beam scanning is proposed for application in target detection and tracking.The array is composed of two periodic LWAs with different periods,in which each LWA generates a narrow beam through the n=-1 space harmonic.Due to the two different periods for the two LWAs,two beams with two different directions can be realized,which can be combined into a sum beam when the array is fed in phase or into a difference beam when the array is fed 180?out of phase.The array integrated with 180?hybrid is designed,fabricated,and measured.Measurement results show that the sum beam can reach a gain up to 15.9 dBi and scan from-33.4?to 20.8?.In the scanning range,the direction of the null in the difference beam is consistent with the direction of the sum beam,with the lowest null depth of-40.8 dB.With the excellent performance,the antenna provides an alternative solution with low complexity and low cost for target detection and tracking.展开更多
We propose a uniform backfire-to-endfire leaky-wave antenna(LWA)based on a topological one-way waveguide under external bias magnetic field.We systematically analyze the dispersion,showing that the proposed structure ...We propose a uniform backfire-to-endfire leaky-wave antenna(LWA)based on a topological one-way waveguide under external bias magnetic field.We systematically analyze the dispersion,showing that the proposed structure supports leaky mode arisen from total internal reflection.By means of tuning frequency or magnetic field,we obtain fixed-bias frequency and fixed-frequency bias LWA with continuous beam scanning from backward,broadside to forward direction.More importantly,we,for the first time,demonstrate that this proposed LWA shows mechanical tunability,allowing us to manipulate the radiation direction from backward,broadside to forward direction by mechanically tuning the air layer thickness.The simulated results show that our system exhibits super low 3dB beam width,high radiation efficiency as well as high antenna gain.Being provided such multiple controlled(especially mechanically)beam scanning manners,the present LWA paves an advanced approach for continuous beam scanning,holding a great potential for applications in modern communication and radar system.展开更多
A compact high-scanning-rate circular-polarized leaky-wave antenna(LWA)based on a meandering substrate integrated waveguide(SIW)with defected ground structures(DGSs)is presented.The meandering-SIW design is employed t...A compact high-scanning-rate circular-polarized leaky-wave antenna(LWA)based on a meandering substrate integrated waveguide(SIW)with defected ground structures(DGSs)is presented.The meandering-SIW design is employed to enhance the beam scanning rate,while circular polarization is achieved by etchingπ-shaped slots on the top plane.To suppress the open stopband at broadside,offset circular DGSs are periodically etched on the ground plane.Their impact on the reflection coefficient and axial ratio is then analyzed through a parametric study.A prototype of the antenna is simulated,fabricated,and measured.Both simulated and measured results indicate a scanning rate of approximately 8.6,with continuous beam scanning from-41°to 59°across the 11.3-12.7 GHz operating band.The antenna maintains an axial ratio below 3 dB within the 11.5-12.3 GHz range.This design shows promise for use in wireless communication systems,particularly in environments with increasingly limited spectrum resources.展开更多
The Fabry-Perot resonator (FPR) antenna has found wide applications in microwave and millimeter waves and recently attracted considerable interest. In this paper, a summary of planar and cylindrical structures, analyt...The Fabry-Perot resonator (FPR) antenna has found wide applications in microwave and millimeter waves and recently attracted considerable interest. In this paper, a summary of planar and cylindrical structures, analytic models and research development is presented, and a comparison between these structures and analytic models is made, showing that such analytic models as the FP cavity mode, electromagnetic band gap (EBG) defect mode, transmission line mode, and leaky-wave mode are consistent when applied to analyze this type of resonator antenna. Some interesting topics under recent research, including dual or multi-band, improvement of gain bandwidth, low profile and beam control, are surveyed.展开更多
Due to the exponentially growing global mobile data of wireless communications evolving from 5 G to 6 G in recent years,research activities of leveraging terahertz(THz)waves to obtain larger channel capacities have sh...Due to the exponentially growing global mobile data of wireless communications evolving from 5 G to 6 G in recent years,research activities of leveraging terahertz(THz)waves to obtain larger channel capacities have shown an ever-increasing pace and reached an unprecedented height than before.Historically,the past few decades have already witnessed much progress in THz generation and detection technologies,which have been recognized for a long time as the bottleneck preventing the THz waves from being tamed by human beings.How-ever,the importance of developing advanced components such as antennas,transmission lines,filters,power amplimers,etc.,which constitute the basic building blocks of a THz wireless system,should not be overlooked for the sake of exploiting the THz spectra for future advanced wireless communications,sensing and imaging applications.While producing a scannable highly-directive antenna beam proves to be indispensable in the pe-riod of microwaves,the significance of such functionality is more critical in the THz era,considering that THz waves have more intractable challenges such as the severity of free-space propagation losses,the susceptibility to atmospheric environments,and the unavailability of efficient signal sources.This article is structured under this background,which is dedicated to reviewing several enabling beam-scanning antenna concepts,structures,and architectures that have been developed for THz wireless systems.Specifically,we divide these THz beam-scanning solutions into four basic groups based on different mechanisms,i.e.,mechanical motion,phased array,frequency beam-scanning,and reconfigurable metasurfaces.展开更多
文摘The work in this article focuses on developing and improving the performance of new leaky-wave antenna configurations that can be adapted for use in radar systems. The study focused on the W-band, where we demonstrated the possibility of modifying resonant frequencies and reducing the number of patches required. The antenna was designed using HFSS, based on the finite element method. It we designed enabled us to observe the influence of the number of patches on the radiation pattern, and also to achieve low levels of minor’s lobes. and good directivity at the operating frequency. These patches are arranged in the shape of an inverted T. The interest of this study is to meet the requirements of radar antennas dedicated to detection.
文摘The development of space telecommunications in recent years has necessitated the design and the realization of compact, high-performance equipment operating at increasingly high frequencies. The use of high-precision radars for surveillance, detection and mobile communication systems orients research toward the antennas to electronic sweep. In this article, we present a microstrip leaky-wave antenna with periodic patches. Its design is based on an integral formulation solved by software using HFSS finite elements. A parametric study of this antenna is validated by simulations and compared with other results found in the literature. Analysis of the antenna’s radiation parameters shows that the main beam direction and levels of minor’s lobes can be controlled from these geometrical parameters. The interest of this study is to meet the requirements of antennas dedicated telecommunications systems.
基金supported by the Natural Science Foundation of Tianjin (No.19JCYBJC16100)the Tianjin Innovation and Entrepreneurship Training Program (No.202210060027)。
文摘In this paper, we propose a single-port dual-beam leaky-wave antenna(LWA) in the terahertz(THz) band based on a composite spoof surface plasmon polariton(SSPP) waveguide. The antenna can generate three independent transmission channels by exciting two independent modes inherent to hole and groove structures, respectively. By periodic modulation of the hole and groove structures, we achieve dual-beam scanning through a broad radiation angle using only the -1st space harmonics of the two modes, hence avoiding the instability of the -2rd space harmonic. Within the operating frequency range of 0.62—0.85 THz, the gain ranges from 13.5 d Bi to 17 d Bi for the backward beam, and from 6 d Bi to 11.8 d Bi for the forward beam. The antenna can accomplish continuous backward beam through broadside to forward beam scanning with a total scanning range of 116° and an average efficiency of about 92%. The antenna exhibits a great potential in the design of multi-transceiver radar system in the THz band and multi-beam LWAs.
基金This project was supported by the National Natural Science Foundation of China (60271012)the National High Technology Research and Development Program of China (2006AA12A110).
文摘A simple and efficient design scheme of the continuous long slot leaky-wave antenna is developed. The key steps involved in the scheme are summarized. First, the cut-off frequencies of slot waveguides with different slot offsets are obtained by 3D finite-difference time-domain （FDTD） method, Second, the attenuation function a^a is estimated by the aperture distribution, and the attenuation function αrs is determined by the slot radiation. Finally, the attenuation function αrs is combined with the attenuation function αrs by the coefficient K. And an example in Ka band is presented. Moreover, the return loss of the E-plane Tee-junction （ET） and the radiation pattern of leaky-wave antenna are simulated. The scheme is verified by comparing with the experimental result.
文摘A novel leaky-wave antenna(LWA)utilizing spoof surface plasmon polaritons(SSPPs)excitation is proposed with continuous scanning range from endfire to forward.The designed transmission line unit supports two SSPPS modes,of which the 2nd order mode is applied in the design.A novel strategy has been devised to excite the spatial radiation of the-1st order harmonics by arranging periodic counter changed sinusoidal structures on both sides of the SSPPs transmission line.Both full-wave simulation and measurement results show that the proposed LWA presents wide scanning angle from endfire to forward.In the frequency range from 4 GHz to 10 GHz,LWAs achieve scanning from 90°to+20°,covering the entire backward quadrant continuously.
基金Project supported by the National Natural Science Foundation of China(Grant No.61372034)
文摘In this paper, we first propose a metamaterial structure by etching the same two interdigital fingers on the upper ground of quarter mode substrate integrated waveguide（QMSIW）. The simulated results show that the proposed QMSIWbased metamaterial has a continuous phase constant changing from negative to positive values within its passband. A periodic leaky-wave antenna（LWA）, which consists of 11 QMSIW-based metamaterial unit cells, is designed, fabricated,and measured. The measured results show that the fabricated antenna achieves a continuous beam scanning property from backward-43° to forward ＋32° over an operating frequencyrange of 8.9 GHz–11.8 GHz with return loss better than 10 d B.The measured antenna gain keeps consistent with the variation of less than 2 d B over the operating frequency range with a maximum gain of 12 d B. Besides, the measured and simulated results are in good agreement with each other, indicating the significance and effectiveness of this method.
基金the National Natural Science Foundation of China(NSFC)under Grants 62071306 and 61801299in part by the Mobil⁃ity Program for Taiwan Young Scientists under Grant RW2019TW001and in part by Shenzhen Science and Technology Program under Grants GJHZ20180418190529516 and JSGG20180507183215520.
文摘Since leaky-wave antennas(LWAs)have the advantages of high directivity,low loss and structural simplicity,LWAs are very suitable for designing millimeter-wave(mmW)antennas.The purpose of this paper is to review the latest research progress of LWAs for 5G/B5G mobile communication systems.Firstly,the conventional classification and design methods of LWAs are introduced and the effects of the phase constant and attenuation constant on the radiation characteristics are discussed.Then two types of new LWAs for 5G/B5G mobile communication systems including broadband fixed-beam LWAs and frequencyfixed beam-scanning LWAs are summarized.Finally,the challenges and future research directions of LWAs for 5G/B5G mobile communication systems are presented.
基金Project supported in part by the National Natural Science Foundation of China(No.62171480)in part by the Guangdong Basic and Applied Basic Research Foundation,China(No.2020B1515020053)。
文摘An array of two substrate-integrated waveguide(SIW)periodic leaky-wave antennas(LWAs)with sum and difference beam scanning is proposed for application in target detection and tracking.The array is composed of two periodic LWAs with different periods,in which each LWA generates a narrow beam through the n=-1 space harmonic.Due to the two different periods for the two LWAs,two beams with two different directions can be realized,which can be combined into a sum beam when the array is fed in phase or into a difference beam when the array is fed 180?out of phase.The array integrated with 180?hybrid is designed,fabricated,and measured.Measurement results show that the sum beam can reach a gain up to 15.9 dBi and scan from-33.4?to 20.8?.In the scanning range,the direction of the null in the difference beam is consistent with the direction of the sum beam,with the lowest null depth of-40.8 dB.With the excellent performance,the antenna provides an alternative solution with low complexity and low cost for target detection and tracking.
基金This work was supported by the National Natural Science Foundation of China(NSFC)(Grant No.61372005)the National Natural Science Foundation of China(NSFC)under the key project(Grant No.41331070)+1 种基金the Natural Science Foundation of Ningbo(No.2019A610081)Zhejiang Provincial Natural Science Foundation of China(No.LY20F050006).
文摘We propose a uniform backfire-to-endfire leaky-wave antenna(LWA)based on a topological one-way waveguide under external bias magnetic field.We systematically analyze the dispersion,showing that the proposed structure supports leaky mode arisen from total internal reflection.By means of tuning frequency or magnetic field,we obtain fixed-bias frequency and fixed-frequency bias LWA with continuous beam scanning from backward,broadside to forward direction.More importantly,we,for the first time,demonstrate that this proposed LWA shows mechanical tunability,allowing us to manipulate the radiation direction from backward,broadside to forward direction by mechanically tuning the air layer thickness.The simulated results show that our system exhibits super low 3dB beam width,high radiation efficiency as well as high antenna gain.Being provided such multiple controlled(especially mechanically)beam scanning manners,the present LWA paves an advanced approach for continuous beam scanning,holding a great potential for applications in modern communication and radar system.
文摘A compact high-scanning-rate circular-polarized leaky-wave antenna(LWA)based on a meandering substrate integrated waveguide(SIW)with defected ground structures(DGSs)is presented.The meandering-SIW design is employed to enhance the beam scanning rate,while circular polarization is achieved by etchingπ-shaped slots on the top plane.To suppress the open stopband at broadside,offset circular DGSs are periodically etched on the ground plane.Their impact on the reflection coefficient and axial ratio is then analyzed through a parametric study.A prototype of the antenna is simulated,fabricated,and measured.Both simulated and measured results indicate a scanning rate of approximately 8.6,with continuous beam scanning from-41°to 59°across the 11.3-12.7 GHz operating band.The antenna maintains an axial ratio below 3 dB within the 11.5-12.3 GHz range.This design shows promise for use in wireless communication systems,particularly in environments with increasingly limited spectrum resources.
基金Project (Nos. 60671016 and 60621002) supported by the National Natural Science Foundation of China
文摘The Fabry-Perot resonator (FPR) antenna has found wide applications in microwave and millimeter waves and recently attracted considerable interest. In this paper, a summary of planar and cylindrical structures, analytic models and research development is presented, and a comparison between these structures and analytic models is made, showing that such analytic models as the FP cavity mode, electromagnetic band gap (EBG) defect mode, transmission line mode, and leaky-wave mode are consistent when applied to analyze this type of resonator antenna. Some interesting topics under recent research, including dual or multi-band, improvement of gain bandwidth, low profile and beam control, are surveyed.
基金supported by grants from the Natural Science Foundation of Jiangsu Province(BK20241276)the University Grants Committee/Research Grants Council of the Hong Kong Special Administrative Region,China(AoE/E-101/23-N and CityU 9610655)+3 种基金the Start-up Research Fund of Southeast University(RF1028623258)the Key Laboratory for Information Science of Electromagnetic Waves,Fudan University(EMW202401)the National Key Research and Development Program of China(2023YFB2906103)the National Natural Science Foundation of China(62122019).
文摘Due to the exponentially growing global mobile data of wireless communications evolving from 5 G to 6 G in recent years,research activities of leveraging terahertz(THz)waves to obtain larger channel capacities have shown an ever-increasing pace and reached an unprecedented height than before.Historically,the past few decades have already witnessed much progress in THz generation and detection technologies,which have been recognized for a long time as the bottleneck preventing the THz waves from being tamed by human beings.How-ever,the importance of developing advanced components such as antennas,transmission lines,filters,power amplimers,etc.,which constitute the basic building blocks of a THz wireless system,should not be overlooked for the sake of exploiting the THz spectra for future advanced wireless communications,sensing and imaging applications.While producing a scannable highly-directive antenna beam proves to be indispensable in the pe-riod of microwaves,the significance of such functionality is more critical in the THz era,considering that THz waves have more intractable challenges such as the severity of free-space propagation losses,the susceptibility to atmospheric environments,and the unavailability of efficient signal sources.This article is structured under this background,which is dedicated to reviewing several enabling beam-scanning antenna concepts,structures,and architectures that have been developed for THz wireless systems.Specifically,we divide these THz beam-scanning solutions into four basic groups based on different mechanisms,i.e.,mechanical motion,phased array,frequency beam-scanning,and reconfigurable metasurfaces.
