A novel phased array antenna consisting of 256 elements is presented and experimentally verified for 5G millimeter-wave wireless communications.The antenna integrated with a wave control circuit can perform real-time ...A novel phased array antenna consisting of 256 elements is presented and experimentally verified for 5G millimeter-wave wireless communications.The antenna integrated with a wave control circuit can perform real-time beam scanning by reconfiguring the phase of an antenna unit.The unit,designed at 28 GHz using a simple patch structure with one PIN diode,can be electronically controlled to generate 1 bit phase quantization.A prototype of the antenna is fabricated and measured to demonstrate the feasibility of this approach.The measurement results indicate that the antenna achieves high gain and fast beam-steering,with the scan beams within±60°range and the maximum gain up to 21.7 dBi.Furthermore,it is also tested for wireless video transmission.In ZTE Shanghai,the antenna was used for the 5G New Radio(NR)test.The error vector magnitude(EVM)is less than 3%and the adjacent channel leakage ratio(ACLR)less than−35 dBc,which can meet 5G system requirements.Compared with the conventional phased array antenna,the proposed phased array has the advantages of low power consumption,low cost and conformal geometry.Due to these characteristics,the antenna is promising for wide applications in 5G millimeter-wave communication systems.展开更多
In this work, we performed first-principles electromagnetic-kinetic simulations to study a phased antenna array and its interaction with deuterium plasmas within the lower hybrid range of frequency. We first gave wave...In this work, we performed first-principles electromagnetic-kinetic simulations to study a phased antenna array and its interaction with deuterium plasmas within the lower hybrid range of frequency. We first gave wave accessibility and resonance results, which agree well with theoretical prediction. In addition, we further investigated the antenna power spectrum with different antenna phases in the presence of the plasma and compared it with that in a vacuum,which directly indicates wave coupling and plasma absorption. Furthermore, for the case with zero phasing difference, our simulation results show that, albeit the launch is away from the accessibility region, tunneling effect and mode conversion occurred, which enhanced coupling and absorption. Moreover, consistent interactions between the injected wave and the plasma concerning various antenna phase differences are shown. We presented the inchoate response of the plasma in terms of the launching directions. Our results could be favorable for the engineering design of wave heating experiments with a tunable phased antenna array in linear devices, such as simple magnetic mirrors or tandem mirrors.展开更多
Designing a sparse array with reduced transmit/receive modules(TRMs)is vital for some applications where the antenna system’s size,weight,allowed operating space,and cost are limited.Sparse arrays exhibit distinct ar...Designing a sparse array with reduced transmit/receive modules(TRMs)is vital for some applications where the antenna system’s size,weight,allowed operating space,and cost are limited.Sparse arrays exhibit distinct architectures,roughly classified into three categories:Thinned arrays,nonuniformly spaced arrays,and clustered arrays.While numerous advanced synthesis methods have been presented for the three types of sparse arrays in recent years,a comprehensive review of the latest development in sparse array synthesis is lacking.This work aims to fill this gap by thoroughly summarizing these techniques.The study includes synthesis examples to facilitate a comparative analysis of different techniques in terms of both accuracy and efficiency.Thus,this review is intended to assist researchers and engineers in related fields,offering a clear understanding of the development and distinctions among sparse array synthesis techniques.展开更多
In this paper,an antenna array composed of circular array and orthogonal linear array is proposed by using the design of long and short baseline“orthogonal linear array”and the circular array ambiguity resolution de...In this paper,an antenna array composed of circular array and orthogonal linear array is proposed by using the design of long and short baseline“orthogonal linear array”and the circular array ambiguity resolution design of multi-group baseline clustering.The effectiveness of the antenna array in this paper is verified by sufficient simulation and experiment.After the system deviation correction work,it is found that in the L/S/C/X frequency bands,the ambiguity resolution probability is high,and the phase difference system error between each channel is basically the same.The angle measurement error is less than 0.5°,and the positioning error is less than 2.5 km.Notably,as the center frequency increases,calibration consistency improves,and the calibration frequency points become applicable over a wider frequency range.At a center frequency of 11.5 GHz,the calibration frequency point bandwidth extends to 1200 MHz.This combined antenna array deployment holds significant promise for a wide range of applications in contemporary wireless communication systems.展开更多
The beam scan with variable linear polarization directions of antenna arrays using MM/C transmit-receive (T/R) modules is explored. It is shown that the beam scan and the polarizations of electric fields can be contro...The beam scan with variable linear polarization directions of antenna arrays using MM/C transmit-receive (T/R) modules is explored. It is shown that the beam scan and the polarizations of electric fields can be controlled simultaneously if the forms of module arrangement are chosen properly and the amplitudes and the phases of array excitation are determined by the method presented in this article. Moreover, the calculations of the amplitudes and the phases of array excitation are simplified greatly while using the bounded conditions properly, and the desired beam sweep rate is achieved.展开更多
In this paper, a novel direction of arrival(DOA) estimation algorithm using directional antennas in cylindrical conformal arrays(CCAs) is proposed. To eliminate the shadow effect, we divide the CCAs into several subar...In this paper, a novel direction of arrival(DOA) estimation algorithm using directional antennas in cylindrical conformal arrays(CCAs) is proposed. To eliminate the shadow effect, we divide the CCAs into several subarrays to obtain the complete output vector. Considering the anisotropic radiation pattern of a CCA, which cannot be separated from the manifold matrix, an improved interpolation method is investigated to transform the directional subarray into omnidirectional virtual nested arrays without non-orthogonal perturbation on the noise vector. Then, the cross-correlation matrix(CCM) of the subarrays is used to generate the consecutive co-arrays without redundant elements and eliminate the noise vector. Finally, the full-rank equivalent covariance matrix is constructed using the output of co-arrays,and the unitary estimation of the signal parameters via rotational invariance techniques(ESPRIT) is performed on the equivalent covariance matrix to estimate the DOAs with low computational complexity. Numerical simulations verify the superior performance of the proposed algorithm, especially under a low signal-to-noise ratio(SNR) environment.展开更多
An improved adaptive genetic algorithm is presented in this paper. It primarily includes two modified methods： one is novel adaptive probabilities of crossover and mutation, the other is truncated selection approach....An improved adaptive genetic algorithm is presented in this paper. It primarily includes two modified methods： one is novel adaptive probabilities of crossover and mutation, the other is truncated selection approach. This algorithm has been validated to be superior to the simple genetic algorithm （SGA） by a complicated binary testing function. Then the proposed algorithm is applied to optimizing the planar retrodirective array to reduce the cost of the hardware. The fitness function is discussed in the optimization example. After optimization, the sparse planar retrodirective antenna array keeps excellent retrodirectivity, while the array architecture has been simplified by 34%. The optimized antenna array can replace uniform full array effectively. Results show that this work will gain more engineering benefits in practice.展开更多
In this paper,we propose the decoupling technique of patch antenna array by suppressing near-field magnetic coupling（NFMC） using magnetic metamaterials.To this end,a highly-integrated magnetic metamaterials,the subs...In this paper,we propose the decoupling technique of patch antenna array by suppressing near-field magnetic coupling（NFMC） using magnetic metamaterials.To this end,a highly-integrated magnetic metamaterials,the substrate-integrated split-ring resonator（SI-SRR）,is firstly proposed to achieve negative permeability at the antenna operating frequency.By integrating SI-SRR in between two closely spaced antennas,magnetic fields are blocked in the shared substrate due to negative permeability of SI-SRR,reducing NFMC between the two antennas.To verify the technique,a prototype was fabricated and measured.The measured results demonstrated that the isolation can be enhanced by more than 17 dB even when the gap between the two patch antennas is only about 0.067 A.Due to high integration,this technique provides an effective alternative to high-isolation antenna array.展开更多
This paper considers the coupling analysis of phased antenna array designed to excite fast wave in the ion cyclotron range of frequency. The coupling of the antenna is calculated in slab geometry. The coupling code ba...This paper considers the coupling analysis of phased antenna array designed to excite fast wave in the ion cyclotron range of frequency. The coupling of the antenna is calculated in slab geometry. The coupling code based on the variational principle gives the self-consistent current flowing in the antenna, this method has been extended so that it can be applied to a phased antenna array. As an example, this paper analyses the coupling prosperities of a 2 × 2 phased antenna array. It gives the optimum geometry of antenna array. The fields excited at plasma surface are found to more or less correspond to the antenna current phasing.展开更多
In this paper, a multi-band metasurface（MS） antenna array with low radar cross section（RCS） performance is proposed and measured. Firstly, a 44 antenna array is composed of four 22 Jerusalem cross structure antenn...In this paper, a multi-band metasurface（MS） antenna array with low radar cross section（RCS） performance is proposed and measured. Firstly, a 44 antenna array is composed of four 22 Jerusalem cross structure antenna arrays working at different frequency bands, which is aimed at enhancing the bandwidth effectively. Then, each antenna can be seen as a unit of MS in spite of adding the feeding structure. Based on phase cancellation principle, the MS is arranged into a chessboard configuration in order to realize wideband RCS reduction. Thus, excellent radiation and scattering characteristics are obtained simultaneously. Simulated and measured results indicate that this work provides a novel method to achieve bandwidth expansion as well as wideband RCS reduction of the antenna array.展开更多
A novel approach devoted to achieving ultra-wideband radar cross section reduction（RCSR） of a waveguide slot antenna array（WGSAA） while maintaining its radiation performance is proposed. Three kinds of artificial ...A novel approach devoted to achieving ultra-wideband radar cross section reduction（RCSR） of a waveguide slot antenna array（WGSAA） while maintaining its radiation performance is proposed. Three kinds of artificial magnetic conductors（AMCs） tiles consisting of three types of basic units resonant at different frequencies are designed and arranged in a novel quadruple-triangle-type configuration to create a composite planar metasurface. The proposed metasurface is characterized by low radar feature over an ultra-wideband based on the principle of phase cancellation. Both simulated and measured results demonstrate that after the composite metasurface is used to cover part of the antenna array, an ultrawideband RCSR involving in-band and out-of-band is achieved for co-and cross-polarized incident waves based on energy cancellation, while the radiation performance is well retained. The proposed method is simple, low-cost, and easy-tofabricate, providing a new method for ultra-wideband RCSR of an antenna array. Moreover, the method proposed in this paper can easily be applied to other antenna architectures.展开更多
In this paper,a self-adaptive method for the Maxwell’s Equations Derived Optimization(MEDO)is proposed.It is implemented by applying the Sequential Model-Based Optimization(SMBO)algorithm to the iterations of the MED...In this paper,a self-adaptive method for the Maxwell’s Equations Derived Optimization(MEDO)is proposed.It is implemented by applying the Sequential Model-Based Optimization(SMBO)algorithm to the iterations of the MEDO,and achieves the automatic adjustment of the parameters.The proposed method is named as adaptive Maxwell’s equations derived optimization(AMEDO).In order to evaluate the performance of AMEDO,eight benchmarks are used and the results are compared with the original MEDO method.The results show that AMEDO can greatly reduce the workload of manual adjustment of parameters,and at the same time can keep the accuracy and stability.Moreover,the convergence of the optimization can be accelerated due to the dynamical adjustment of the parameters.In the end,the proposed AMEDO is applied to the side lobe level suppression and array failure correction of a linear antenna array,and shows great potential in antenna array synthesis.展开更多
An uncommon fractal construction method is applied in the microwave element design. A novel fractal defected ground structure （DGS） based on micro electro-mechanical system （MEMS） is proposed. The size of this nov...An uncommon fractal construction method is applied in the microwave element design. A novel fractal defected ground structure （DGS） based on micro electro-mechanical system （MEMS） is proposed. The size of this novel fractal DGS can achieve 86% size reduction compared with the conventional dumbbell type DGS. This novel fractal DGS is used in the miniaturization design of L-band microstrip antenna array. The simulation result shows that this novel fractal DGS can effectively reduce the mutual coupling between the antenna elements, so it is helpful to the miniaturization of microstrip array, namely the approximately same gain value can be achieved with the shorter distance between elements.展开更多
An efficient analyzing approach is presented for large slotted-waveguide antenna arrays by using hybrid finite element-boundary integral-multilevel fast multipole algorithm（FE-BI-MLFMA）in this paper.A simple computa...An efficient analyzing approach is presented for large slotted-waveguide antenna arrays by using hybrid finite element-boundary integral-multilevel fast multipole algorithm（FE-BI-MLFMA）in this paper.A simple computation model for slotted-waveguide antenna is presented by using thin current probe excitation and perfectly matched layer（PML）absorber.Since each slotted-waveguide antenna can be considered as a single sub-domain,the domain decomposition algorithm（DDA）can be applied to FE-BI-MLFMA to greatly reduce the computation resources and achieve high efficiency.This DDA-FE-BI-MLMFA is parallelized to further strength its capability.The comparisons of the computed radiation patterns with measured data and results from the commercial software show that our method has good accuracy for slottedwaveguide array.Then the influence of mutual coupling between adjacent slotted-waveguides is studied.To demonstrate capability of the presented method,a carefully designed large X-band slotted-waveguide antenna array containing eighteen waveguides with Taylor amplitude and inverse phase excitation distribution are analyzed in the paper.展开更多
A novel low radar cross-section(RCS)and high gain patch antenna array is proposed.A pair of slots introduced on the mushroom electromagnetic bandgap(EBG)patch realize polarization-dependency and act as parasitic radia...A novel low radar cross-section(RCS)and high gain patch antenna array is proposed.A pair of slots introduced on the mushroom electromagnetic bandgap(EBG)patch realize polarization-dependency and act as parasitic radiation to enhance the antenna gain.A chessboard-like configuration composed of slot-EBG blocks is further equipped on the antenna array for scattering cancellation.Optimizing the layout pattern enables the designing of a high-gain and low-RCS antenna array using the slot-EBGs.Full-wave simulations validate that a front gain enhancement of more than 2.5.dB in the operating frequency band and low-RCS in a broad frequency band for normal incidence are obtained by the proposed antenna array.展开更多
In recent years, microstrip antennas have been more widely applied in satellite communications, mobile phones, unmanned aerial vehicle （UAV）, and weapons. A micro-electro-mechanical systems-based （MEMS-based） high...In recent years, microstrip antennas have been more widely applied in satellite communications, mobile phones, unmanned aerial vehicle （UAV）, and weapons. A micro-electro-mechanical systems-based （MEMS-based） high-resistance silicon C-band microstrip antenna array has been designed for the intelligent ammunition. The center frequency is 4.5 GHz. A cavity has been designed in substrate to reduce the dielectric constant of silicon and high-resistance silicon has been used as the material of substrate to improve the gain of antenna. It is very easy to be manufactured by using MEMS technology because of the improved structure of the antenna. The results show that the gain of the antenna is 8 dB and voltage standing wave ratio （VSWR） is less than 2 by the analysis and simulation in high freauencv structure simulator （HFSS）.展开更多
A multiple frequency cancellation(MFC)method is proposed for stealth design of ultra-wide band(UWB)end-fire antenna array.The proposed method can produce significant radar cross section(RCS)reduction in the whole oper...A multiple frequency cancellation(MFC)method is proposed for stealth design of ultra-wide band(UWB)end-fire antenna array.The proposed method can produce significant radar cross section(RCS)reduction in the whole operating band.The 1×4 and 4×4 Vivaldi antenna arrays of different kinds of cancellation structures are discussed as examples to validate the effectiveness of the MFC method on both linear and planar arrays.On average,22.6 dB reduction of monostatic radar cross section(MRCS)is obtained in the whole X-band.MRCS under oblique incident waves is also reduced within±60°.Basically favorable radiation characteristics are maintained.展开更多
Monopulse slot antenna arrays based on substrate integrated waveguide （SIW） are proposed for the application of 60 GHz mono- pulse tracking systems in this paper. The sum-difference monopulse comparator can provide ...Monopulse slot antenna arrays based on substrate integrated waveguide （SIW） are proposed for the application of 60 GHz mono- pulse tracking systems in this paper. The sum-difference monopulse comparator can provide a high amplitude and phase balance over wide frequency band and no phase delay technique is required for the difference channel. Resonant slot antennas are adopted as the radiating elements since they can be integrated with the sum-difference monopulse comparator in a single layer with a compact size. Two monopulse arrays with 2× 4 and 4×4 slot elements are designed, fabricated, and measured. Measured results show that the proposed antenna arrays have wide bandwidth covering the unlicensed 60-GHz band. The peak sum beam gain is 13.85 dBi for the 2 ×4 element array and 16.24 dBi for the 4×4 element array. The peak difference beam gain is 11.20 dBi for the 2×4 element array and 12.11 dBi for the 4×4 element array and the maximum null depth can reach -40 dB.展开更多
A novel differential quasi-Yagi antenna is first presented and compared with a normal single-ended counterpart.The simulated and measured results show that the differential quasi-Yagi antenna outperforms the conventio...A novel differential quasi-Yagi antenna is first presented and compared with a normal single-ended counterpart.The simulated and measured results show that the differential quasi-Yagi antenna outperforms the conventional single-ended one.The differential quasi-Yagi antenna is then used as an element for linear arrays.A study of the coupling mechanism between the two differential and the two singleended quasi-Yagi antennas is conducted,which reveals that the TE0 mode is the dominant mode,and the driver is the decisive part to account for the mutual coupling.Next,the effects of four decoupling structures are respectively evaluated between the two differential quasi-Yagi antennas.Finally,the arrays with simple but effective decoupling structures are fabricated and measured.The measured results demonstrate that the simple slit or air-hole decoupling structure can reduce the coupling level from−18 dB to−25 dB and meanwhile maintain the impedance matching and radiation patterns of the array over the broad bandwidth.The differential quasi-Yagi antenna should be a promising antenna candidate for many applications.展开更多
In this paper, an ultra-compact single negative（SNG） electric waveguided metamaterial（WG-MTM） is first investigated and used to reduce the mutual coupling in E ＆ H planes of a dual-band microstrip antenna array. ...In this paper, an ultra-compact single negative（SNG） electric waveguided metamaterial（WG-MTM） is first investigated and used to reduce the mutual coupling in E ＆ H planes of a dual-band microstrip antenna array. The proposed SNG electric WG-MTM unit cell is designed by etching two different symmetrical spiral lines on the ground, and has two stopbands operating at 1.86 GHz and 2.40 GHz. The circuit size is very compact, which is only λ_0/33.6 ×λ_0/15.1（where λ_0 is the wavelength at 1.86 GHz in free space）. Taking advantage of the dual-stopband property of the proposed SNG electric WG-MTM, a dual-band microstrip antenna array operating at 1.86 GHz and 2.40 GHz with very low mutual coupling is designed by embedding a cross shaped array of the proposed SNG electric WG-MTM. The measured and simulated results of the designed dual-band antenna array are in good agreement with each other, indicating that the mutual coupling of the fabricated dual-band antenna array realizes 9.8/11.1 d B reductions in the H plane, 8.5/7.9 d B reductions in the E plane at1.86 GHz and 2.40 GHz, respectively. Besides, the distance of the antenna elements in the array is only 0.35 λ_0（where λ_0 is the wavelength at 1.86 GHz in free space）. The proposed strategy is used for the first time to reduce the mutual coupling in E ＆ H planes of the dual-band microstrip antenna array by using ultra-compact SNG electric WG-MTM.展开更多
文摘A novel phased array antenna consisting of 256 elements is presented and experimentally verified for 5G millimeter-wave wireless communications.The antenna integrated with a wave control circuit can perform real-time beam scanning by reconfiguring the phase of an antenna unit.The unit,designed at 28 GHz using a simple patch structure with one PIN diode,can be electronically controlled to generate 1 bit phase quantization.A prototype of the antenna is fabricated and measured to demonstrate the feasibility of this approach.The measurement results indicate that the antenna achieves high gain and fast beam-steering,with the scan beams within±60°range and the maximum gain up to 21.7 dBi.Furthermore,it is also tested for wireless video transmission.In ZTE Shanghai,the antenna was used for the 5G New Radio(NR)test.The error vector magnitude(EVM)is less than 3%and the adjacent channel leakage ratio(ACLR)less than−35 dBc,which can meet 5G system requirements.Compared with the conventional phased array antenna,the proposed phased array has the advantages of low power consumption,low cost and conformal geometry.Due to these characteristics,the antenna is promising for wide applications in 5G millimeter-wave communication systems.
基金supported by the National Key R&D Program of China (No. 2017YFE0301802)National Natural Science Foundation of China (Nos. 11905220, 11775219 and 12175226)。
文摘In this work, we performed first-principles electromagnetic-kinetic simulations to study a phased antenna array and its interaction with deuterium plasmas within the lower hybrid range of frequency. We first gave wave accessibility and resonance results, which agree well with theoretical prediction. In addition, we further investigated the antenna power spectrum with different antenna phases in the presence of the plasma and compared it with that in a vacuum,which directly indicates wave coupling and plasma absorption. Furthermore, for the case with zero phasing difference, our simulation results show that, albeit the launch is away from the accessibility region, tunneling effect and mode conversion occurred, which enhanced coupling and absorption. Moreover, consistent interactions between the injected wave and the plasma concerning various antenna phase differences are shown. We presented the inchoate response of the plasma in terms of the launching directions. Our results could be favorable for the engineering design of wave heating experiments with a tunable phased antenna array in linear devices, such as simple magnetic mirrors or tandem mirrors.
基金supported by the National Natural Science Foundation of China under Grant No.U2341208.
文摘Designing a sparse array with reduced transmit/receive modules(TRMs)is vital for some applications where the antenna system’s size,weight,allowed operating space,and cost are limited.Sparse arrays exhibit distinct architectures,roughly classified into three categories:Thinned arrays,nonuniformly spaced arrays,and clustered arrays.While numerous advanced synthesis methods have been presented for the three types of sparse arrays in recent years,a comprehensive review of the latest development in sparse array synthesis is lacking.This work aims to fill this gap by thoroughly summarizing these techniques.The study includes synthesis examples to facilitate a comparative analysis of different techniques in terms of both accuracy and efficiency.Thus,this review is intended to assist researchers and engineers in related fields,offering a clear understanding of the development and distinctions among sparse array synthesis techniques.
文摘In this paper,an antenna array composed of circular array and orthogonal linear array is proposed by using the design of long and short baseline“orthogonal linear array”and the circular array ambiguity resolution design of multi-group baseline clustering.The effectiveness of the antenna array in this paper is verified by sufficient simulation and experiment.After the system deviation correction work,it is found that in the L/S/C/X frequency bands,the ambiguity resolution probability is high,and the phase difference system error between each channel is basically the same.The angle measurement error is less than 0.5°,and the positioning error is less than 2.5 km.Notably,as the center frequency increases,calibration consistency improves,and the calibration frequency points become applicable over a wider frequency range.At a center frequency of 11.5 GHz,the calibration frequency point bandwidth extends to 1200 MHz.This combined antenna array deployment holds significant promise for a wide range of applications in contemporary wireless communication systems.
文摘The beam scan with variable linear polarization directions of antenna arrays using MM/C transmit-receive (T/R) modules is explored. It is shown that the beam scan and the polarizations of electric fields can be controlled simultaneously if the forms of module arrangement are chosen properly and the amplitudes and the phases of array excitation are determined by the method presented in this article. Moreover, the calculations of the amplitudes and the phases of array excitation are simplified greatly while using the bounded conditions properly, and the desired beam sweep rate is achieved.
基金supported by the National Natural Science Foundation of China (NSFC) [grant number. 61871414]。
文摘In this paper, a novel direction of arrival(DOA) estimation algorithm using directional antennas in cylindrical conformal arrays(CCAs) is proposed. To eliminate the shadow effect, we divide the CCAs into several subarrays to obtain the complete output vector. Considering the anisotropic radiation pattern of a CCA, which cannot be separated from the manifold matrix, an improved interpolation method is investigated to transform the directional subarray into omnidirectional virtual nested arrays without non-orthogonal perturbation on the noise vector. Then, the cross-correlation matrix(CCM) of the subarrays is used to generate the consecutive co-arrays without redundant elements and eliminate the noise vector. Finally, the full-rank equivalent covariance matrix is constructed using the output of co-arrays,and the unitary estimation of the signal parameters via rotational invariance techniques(ESPRIT) is performed on the equivalent covariance matrix to estimate the DOAs with low computational complexity. Numerical simulations verify the superior performance of the proposed algorithm, especially under a low signal-to-noise ratio(SNR) environment.
文摘An improved adaptive genetic algorithm is presented in this paper. It primarily includes two modified methods： one is novel adaptive probabilities of crossover and mutation, the other is truncated selection approach. This algorithm has been validated to be superior to the simple genetic algorithm （SGA） by a complicated binary testing function. Then the proposed algorithm is applied to optimizing the planar retrodirective array to reduce the cost of the hardware. The fitness function is discussed in the optimization example. After optimization, the sparse planar retrodirective antenna array keeps excellent retrodirectivity, while the array architecture has been simplified by 34%. The optimized antenna array can replace uniform full array effectively. Results show that this work will gain more engineering benefits in practice.
基金Project supported in part by the National Natural Science Foundation of China(Grant Nos.61331005,61471388,61501503,61501502,61501497,51575524,61302023,and 11304393)the Natural Science Foundation of Shaanxi Province,China(Grant Nos.2015JM6300 and 2015JM6277)
文摘In this paper,we propose the decoupling technique of patch antenna array by suppressing near-field magnetic coupling（NFMC） using magnetic metamaterials.To this end,a highly-integrated magnetic metamaterials,the substrate-integrated split-ring resonator（SI-SRR）,is firstly proposed to achieve negative permeability at the antenna operating frequency.By integrating SI-SRR in between two closely spaced antennas,magnetic fields are blocked in the shared substrate due to negative permeability of SI-SRR,reducing NFMC between the two antennas.To verify the technique,a prototype was fabricated and measured.The measured results demonstrated that the isolation can be enhanced by more than 17 dB even when the gap between the two patch antennas is only about 0.067 A.Due to high integration,this technique provides an effective alternative to high-isolation antenna array.
文摘This paper considers the coupling analysis of phased antenna array designed to excite fast wave in the ion cyclotron range of frequency. The coupling of the antenna is calculated in slab geometry. The coupling code based on the variational principle gives the self-consistent current flowing in the antenna, this method has been extended so that it can be applied to a phased antenna array. As an example, this paper analyses the coupling prosperities of a 2 × 2 phased antenna array. It gives the optimum geometry of antenna array. The fields excited at plasma surface are found to more or less correspond to the antenna current phasing.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61471389,61701523,and 61671464)
文摘In this paper, a multi-band metasurface（MS） antenna array with low radar cross section（RCS） performance is proposed and measured. Firstly, a 44 antenna array is composed of four 22 Jerusalem cross structure antenna arrays working at different frequency bands, which is aimed at enhancing the bandwidth effectively. Then, each antenna can be seen as a unit of MS in spite of adding the feeding structure. Based on phase cancellation principle, the MS is arranged into a chessboard configuration in order to realize wideband RCS reduction. Thus, excellent radiation and scattering characteristics are obtained simultaneously. Simulated and measured results indicate that this work provides a novel method to achieve bandwidth expansion as well as wideband RCS reduction of the antenna array.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61671464,61701523,and 61471389)
文摘A novel approach devoted to achieving ultra-wideband radar cross section reduction（RCSR） of a waveguide slot antenna array（WGSAA） while maintaining its radiation performance is proposed. Three kinds of artificial magnetic conductors（AMCs） tiles consisting of three types of basic units resonant at different frequencies are designed and arranged in a novel quadruple-triangle-type configuration to create a composite planar metasurface. The proposed metasurface is characterized by low radar feature over an ultra-wideband based on the principle of phase cancellation. Both simulated and measured results demonstrate that after the composite metasurface is used to cover part of the antenna array, an ultrawideband RCSR involving in-band and out-of-band is achieved for co-and cross-polarized incident waves based on energy cancellation, while the radiation performance is well retained. The proposed method is simple, low-cost, and easy-tofabricate, providing a new method for ultra-wideband RCSR of an antenna array. Moreover, the method proposed in this paper can easily be applied to other antenna architectures.
基金the National Nature Science Foundation of China(No.61427803).
文摘In this paper,a self-adaptive method for the Maxwell’s Equations Derived Optimization(MEDO)is proposed.It is implemented by applying the Sequential Model-Based Optimization(SMBO)algorithm to the iterations of the MEDO,and achieves the automatic adjustment of the parameters.The proposed method is named as adaptive Maxwell’s equations derived optimization(AMEDO).In order to evaluate the performance of AMEDO,eight benchmarks are used and the results are compared with the original MEDO method.The results show that AMEDO can greatly reduce the workload of manual adjustment of parameters,and at the same time can keep the accuracy and stability.Moreover,the convergence of the optimization can be accelerated due to the dynamical adjustment of the parameters.In the end,the proposed AMEDO is applied to the side lobe level suppression and array failure correction of a linear antenna array,and shows great potential in antenna array synthesis.
基金supported by the 11th Five-Year Plan under Grant No. 11001030203
文摘An uncommon fractal construction method is applied in the microwave element design. A novel fractal defected ground structure （DGS） based on micro electro-mechanical system （MEMS） is proposed. The size of this novel fractal DGS can achieve 86% size reduction compared with the conventional dumbbell type DGS. This novel fractal DGS is used in the miniaturization design of L-band microstrip antenna array. The simulation result shows that this novel fractal DGS can effectively reduce the mutual coupling between the antenna elements, so it is helpful to the miniaturization of microstrip array, namely the approximately same gain value can be achieved with the shorter distance between elements.
基金Supported by the National Key Basic Research Program(973 Program)(2012CB720702,61320602)the 111 Project of China(B14010)the National Natural Science Foundation of China(61371002)
文摘An efficient analyzing approach is presented for large slotted-waveguide antenna arrays by using hybrid finite element-boundary integral-multilevel fast multipole algorithm（FE-BI-MLFMA）in this paper.A simple computation model for slotted-waveguide antenna is presented by using thin current probe excitation and perfectly matched layer（PML）absorber.Since each slotted-waveguide antenna can be considered as a single sub-domain,the domain decomposition algorithm（DDA）can be applied to FE-BI-MLFMA to greatly reduce the computation resources and achieve high efficiency.This DDA-FE-BI-MLMFA is parallelized to further strength its capability.The comparisons of the computed radiation patterns with measured data and results from the commercial software show that our method has good accuracy for slottedwaveguide array.Then the influence of mutual coupling between adjacent slotted-waveguides is studied.To demonstrate capability of the presented method,a carefully designed large X-band slotted-waveguide antenna array containing eighteen waveguides with Taylor amplitude and inverse phase excitation distribution are analyzed in the paper.
基金National Natural Science Foundation of China(U1730102)the National Key R&D Program of China(2017YFB0202500)。
文摘A novel low radar cross-section(RCS)and high gain patch antenna array is proposed.A pair of slots introduced on the mushroom electromagnetic bandgap(EBG)patch realize polarization-dependency and act as parasitic radiation to enhance the antenna gain.A chessboard-like configuration composed of slot-EBG blocks is further equipped on the antenna array for scattering cancellation.Optimizing the layout pattern enables the designing of a high-gain and low-RCS antenna array using the slot-EBGs.Full-wave simulations validate that a front gain enhancement of more than 2.5.dB in the operating frequency band and low-RCS in a broad frequency band for normal incidence are obtained by the proposed antenna array.
基金supported by the Chinese PLA General Armament Department under Grant No.51318020305
文摘In recent years, microstrip antennas have been more widely applied in satellite communications, mobile phones, unmanned aerial vehicle （UAV）, and weapons. A micro-electro-mechanical systems-based （MEMS-based） high-resistance silicon C-band microstrip antenna array has been designed for the intelligent ammunition. The center frequency is 4.5 GHz. A cavity has been designed in substrate to reduce the dielectric constant of silicon and high-resistance silicon has been used as the material of substrate to improve the gain of antenna. It is very easy to be manufactured by using MEMS technology because of the improved structure of the antenna. The results show that the gain of the antenna is 8 dB and voltage standing wave ratio （VSWR） is less than 2 by the analysis and simulation in high freauencv structure simulator （HFSS）.
基金supported in part by Nanjing University of Aeronautics and Astronautics Research Funding(No. Kfjj20150414)。
文摘A multiple frequency cancellation(MFC)method is proposed for stealth design of ultra-wide band(UWB)end-fire antenna array.The proposed method can produce significant radar cross section(RCS)reduction in the whole operating band.The 1×4 and 4×4 Vivaldi antenna arrays of different kinds of cancellation structures are discussed as examples to validate the effectiveness of the MFC method on both linear and planar arrays.On average,22.6 dB reduction of monostatic radar cross section(MRCS)is obtained in the whole X-band.MRCS under oblique incident waves is also reduced within±60°.Basically favorable radiation characteristics are maintained.
基金This project is supported by the National Basic Research Program of China （＂973＂ Program） under Grant No. 2014CB339900 and the National Natural Science Foundation of China under Grant No. 61372056.
文摘Monopulse slot antenna arrays based on substrate integrated waveguide （SIW） are proposed for the application of 60 GHz mono- pulse tracking systems in this paper. The sum-difference monopulse comparator can provide a high amplitude and phase balance over wide frequency band and no phase delay technique is required for the difference channel. Resonant slot antennas are adopted as the radiating elements since they can be integrated with the sum-difference monopulse comparator in a single layer with a compact size. Two monopulse arrays with 2× 4 and 4×4 slot elements are designed, fabricated, and measured. Measured results show that the proposed antenna arrays have wide bandwidth covering the unlicensed 60-GHz band. The peak sum beam gain is 13.85 dBi for the 2 ×4 element array and 16.24 dBi for the 4×4 element array. The peak difference beam gain is 11.20 dBi for the 2×4 element array and 12.11 dBi for the 4×4 element array and the maximum null depth can reach -40 dB.
文摘A novel differential quasi-Yagi antenna is first presented and compared with a normal single-ended counterpart.The simulated and measured results show that the differential quasi-Yagi antenna outperforms the conventional single-ended one.The differential quasi-Yagi antenna is then used as an element for linear arrays.A study of the coupling mechanism between the two differential and the two singleended quasi-Yagi antennas is conducted,which reveals that the TE0 mode is the dominant mode,and the driver is the decisive part to account for the mutual coupling.Next,the effects of four decoupling structures are respectively evaluated between the two differential quasi-Yagi antennas.Finally,the arrays with simple but effective decoupling structures are fabricated and measured.The measured results demonstrate that the simple slit or air-hole decoupling structure can reduce the coupling level from−18 dB to−25 dB and meanwhile maintain the impedance matching and radiation patterns of the array over the broad bandwidth.The differential quasi-Yagi antenna should be a promising antenna candidate for many applications.
基金Project supported by the National Natural Science Foundation of China(Grant No.61372034)
文摘In this paper, an ultra-compact single negative（SNG） electric waveguided metamaterial（WG-MTM） is first investigated and used to reduce the mutual coupling in E ＆ H planes of a dual-band microstrip antenna array. The proposed SNG electric WG-MTM unit cell is designed by etching two different symmetrical spiral lines on the ground, and has two stopbands operating at 1.86 GHz and 2.40 GHz. The circuit size is very compact, which is only λ_0/33.6 ×λ_0/15.1（where λ_0 is the wavelength at 1.86 GHz in free space）. Taking advantage of the dual-stopband property of the proposed SNG electric WG-MTM, a dual-band microstrip antenna array operating at 1.86 GHz and 2.40 GHz with very low mutual coupling is designed by embedding a cross shaped array of the proposed SNG electric WG-MTM. The measured and simulated results of the designed dual-band antenna array are in good agreement with each other, indicating that the mutual coupling of the fabricated dual-band antenna array realizes 9.8/11.1 d B reductions in the H plane, 8.5/7.9 d B reductions in the E plane at1.86 GHz and 2.40 GHz, respectively. Besides, the distance of the antenna elements in the array is only 0.35 λ_0（where λ_0 is the wavelength at 1.86 GHz in free space）. The proposed strategy is used for the first time to reduce the mutual coupling in E ＆ H planes of the dual-band microstrip antenna array by using ultra-compact SNG electric WG-MTM.
