A broadband planar quasi-Yagi antenna

A novel broadband planar antenna based on the classic Yagi-Uda dipole array is presented. This "quasi-Yagi" antenna achieves a measured 48% bandwidth for VSWR <2, better than 12 dB front-to-back ratio, smaller than -15 dB cross polarization, 3-5 dB absolute gain and a nominal efficiency of 93% across the operating bandwidth. Finite-difference time-domain simulation is used for optimization of the antenna and the results agree very well with measurements. Additionally, a gain-enhanced design is presented, where higher gain has been achieved at the cost of reduced bandwidth. These quasi-Yagi antennas are realized on a high dielectric constant substrate and are completely compatible with microstrip circuitry and solid-state devices. The excellent radiation properties of this antenna make it ideal as either a stand-alone antenna with a broad pattern or as an array element. The antenna should find wide applications in wireless communication systems, power combining, phased arrays and active arrays, as well as millimeter-wave imaging arrays.     

Multi-criteria design methodology of a dielectric resonator antenna with jumping genes evolutionary algorithm

A novel evolutionary computing algorithm, jumping genes evolutionary algorithm (JGEA) is used for designing a dielectric resonator antenna with multiple parasitic strips. This scheme provides an effective methodology for the antenna design, searching for the necessary parameters to achieve the optimal performance. The obtained non-dominated solutions for the antenna configurations have been used to select and determine the appropriate impedance bandwidth and radiation pattern. In the LP DRA optimization, the impedance bandwidth of 21% has been achieved. In the CP DRA optimization, the antenna can be designed to achieve the operation frequency ranged from 3 to 4.2 GHz. The results show enhancement of impedance bandwidth and the CP operation frequency range comparing with the original designs.     

一种基于多维均匀采样与Kriging模型的天线快速优化方法

天线优化设计中,由于经典优化算法一般需要对同一结构的成百上千组参数进行电磁仿真后才能得出最优结果,因此多参数、大范围的天线优化设计存在计算效率问题。该文利用Kriging模型拟合参数空间内样本点的电磁仿真数据,代替电磁仿真实现从结构参数到电磁响应的瞬时近似计算,通过初始阶段的多维均匀拉丁超立方采样算法(LHS-MDU)和优化循环中的新增采样策略,减少电磁仿真次数,提高优化设计效率。利用此方法调整矩形贴片天线的馈点位置和双频单极子天线的振子长度来优化工作频点与阻抗带宽,相比遗传算法,完成相同目标所需的电磁仿真次数分别减少了75%和84%。     

Design of electrically small wire antennas using a pareto genetic algorithm

We report on the use of a genetic algorithm (GA) in the design optimization of electrically small wire antennas, taking into account of bandwidth, efficiency and antenna size. For the antenna configuration, we employ a multisegment wire structure. The Numerical Electromagnetics Code (NEC) is used to predict the performance of each wire structure. To efficiently map out this multiobjective problem, we implement a Pareto GA with the concept of divided range optimization. In our GA implementation, each wire shape is encoded into a binary chromosome. A two-point crossover scheme involving three chromosomes and a geometrical filter are implemented to achieve efficient optimization. An optimal set of designs, trading off bandwidth, efficiency, and antenna size, is generated. Several GA designs are built, measured and compared to the simulation. Physical interpretations of the GA-optimized structures are provided and the results are compared against the well-known fundamental limit for small antennas. Further improvements using other geometrical design freedoms are discussed.     

On the behaviour of a compact antenna system with non-resonant elements in the presence of the human head

A novel handset antenna technique to solve the increasing demand of mobile bands, the loading effects (mismatching and efficiency losses) and the power absorption introduced by the head is analysed in terms of bandwidth, efficiency and SAR (specific absorption rate). The technique proposed integrates non-resonant elements and its results are compared with those obtained by a planar inverted-F antenna. The main antenna parameters (bandwidth, efficiency in free-space, efficiency regarding the human head presence and SAR) are compared in terms of electromagnetic simulation and measurements. The study concludes that the novel antenna architecture achieves multiband operation from 824–960 MHz and 1710–2170 MHz and become robust to human loading while occupying a reduced volume of just 250 mm³ in a typical handset phone.     

Broadband quasi-microstrip antenna

A new printed microwave antenna is presented. The antenna is a hybrid between a wire antenna array and a microstrip patch antenna. Although the size, cost, and efficiency are comparable to the microstrip patch, the voltage standing wave ratio 2:1 bandwidth of the antenna presented here is above 20%. The radiation pattern of the antenna does not change appreciably within the bandwidth, and the theoretical efficiency for optimal antennas remains above approximately 80% within the bandwidth. Measurements on several antennas around 2 and 4 GHz are presented, as well as theoretical results obtained using a full-wave analysis     

Integration of microstrip patch antenna on ceramic ball grid arraypackage

A novel concept of integration of an antenna on an integrated circuit package is proposed for the single-chip solutions of wireless transceivers. A prototype antenna integrated on a thin ceramic ball grid array package is reported. Results show that the antenna achieved impedance bandwidth of 4.65% and radiation efficiency of 65% at 5.52 GHz     

A Compact Zeroth‐Order Resonant Antenna on Vialess CPW Single Layer

In this letter, a novel zeroth‐order resonant (ZOR) antenna on vialess co‐planar waveguide (CPW) is proposed. It is based on a composite right/left‐handed CPW transmission line. To achieve a compact size, this antenna utilizes the ZOR condition, and its reactive parameters determine the resonant frequency. Each unit cell is composed of a metallic top patch and meander lines. Since it is realized on the CPW single layer, the proposed antenna has the benefits of being a compact size and easy to fabricate. The bandwidth of 6.8% and efficiency of 62% are experimentally achieved. Its bandwidth is enhanced compared with other ZOR antennas.     

W-shaped enhanced-bandwidth patch antenna for wireless communication

In this paper a novel form of the familiar E-shaped patch antenna is presented. In the presented approach, by using the genetic algorithm (GA) based on fuzzy decision-making, some modifications have been implemented to the incorporated slots which lead to even more enhancement in the antenna bandwidth. The MOM (Method of Moment) is employed for analysis at the frequency band of 1.8GHz–2.6GHz by the optimization parameters of supply locations and slot dimensions. In the implemented fuzzy system, inputs are parameters like population, and outputs are parameters like recombination to produce the next generation. Fuzzy inference system (FIS) is used for the control of GA parameters. The design is also optimized by successive iterations of a computer-aided analysis package and experimental modifications. Prototype antenna, resonating at wireless communication frequencies of 1.88 and 2.37 GHz, has been constructed and experimental results are in relatively good agreement with the analysis. Dimensions of the modified slots for bandwidth enhancement, while maintaining good radiation characteristics, have been determined and the obtained antenna bandwidth of 36.7% is larger than that of a corresponding unslotted rectangular microstrip antenna or a conventional E-Shaped patch antenna. Details of the antenna design approach and experimental results are presented and discussed.     

大规模MIMO OFDMA下行系统能效资源分配算法

针对大规模多输入多输出（MIMO）正交频分多址(OFDMA)下行移动通信系统,提出了一种基于能效最优的资源分配算法。所提算法在采用迫零(ZF)预编码的情况下,以最大化系统能效的下界为准则,同时考虑每个用户的最低速率要求,通过调整带宽分配、功率分配和基站天线数分配来优化能效函数。首先根据优化条件提出了一种迭代算法确定每个用户的带宽分配,然后利用分数规划的性质并采用凸优化方法,通过联合调整基站端的发射天线数和用户的发射功率来优化能效函数。仿真结果表明,所提算法在较少迭代次数的同时能够取得较好的系统能效性能和吞吐量性能。     

Parallel particle swarm optimization and finite- difference time-domain (PSO/FDTD) algorithm for multiband and wide-band patch antenna designs

This paper presents a novel evolutionary optimization methodology for multiband and wide-band patch antenna designs. The particle swarm optimization (PSO) and the finite-difference time-domain (FDTD) are combined to achieve the optimum antenna satisfying a certain design criterion. The antenna geometric parameters are extracted to be optimized by PSO, and a fitness function is evaluated by FDTD simulations to represent the performance of each candidate design. The optimization process is implemented on parallel clusters to reduce the computational time introduced by full-wave analysis. Two examples are investigated in the paper: first, the design of rectangular patch antennas is presented as a test of the parallel PSO/FDTD algorithm. The optimizer is then applied to design E-shaped patch antennas. It is observed that by using different fitness functions, both dual-frequency and wide-band antennas with desired performance are obtained by the optimization. The optimized E-shaped patch antennas are analyzed, fabricated, and measured to validate the robustness of the algorithm. The measured less than - 18 dB return loss (for dual-frequency antenna) and 30.5% bandwidth (for wide-band antenna) exhibit the prospect of the parallel PSO/FDTD algorithm in practical patch antenna designs.     

Novel design of broad-band stacked patch antenna

A novel broadband stacked E-shaped patch antenna is proposed in this paper. The proposed antenna has an input impedance bandwidth of about 38.41%, better than the conventional E-shaped microstrip patch antenna, which has an input impedance bandwidth of 33.8%. Through the use of the washer on the probe of the stacked patch antenna, the input impedance bandwidth is improved further to 44.9%. The radiation patterns are found to be relatively constant throughout the whole band. Comparisons of these antennas are presented in this paper.     

一种高效率的四脊喇叭馈源

以天线口径效率为目标,研究了四脊喇叭口径对馈源波束等化、波束宽度恒定和天线口径效率等性能的影响,得到了一种3∶1带宽高效率圆四脊喇叭馈源的设计。该馈源在整个频带内具有较低的电压驻波比,三个主平面的主极化方向图波束等化较好,-10d B波束宽度基本恒定,且天线口径效率达到55%以上。     

低剖面宽带圆极化天线阵列

基于双馈双线极化微带天线,结合威尔金森功分器、T形结功分器及顺序旋转馈电的优点,设计了一种新型低剖面宽带圆极化2×2天线阵列。把辐射贴片和馈电网络集成在同一介质层,有效地利用了介质空间,降低了天线的剖面,增加了天线的带宽。4个天线单元顺序旋转90°,利用一分四T形结功分器给4个单元等幅、相位依次相差90°馈电。根据Ansoft''s HFSS仿真结果,制作了样机。样机实测结果和仿真结果吻合。实测结果表明,该天线阵驻波带宽可以达到27.78%,3-dB轴比带宽可以达到52%,最大增益为14.19 dB。     

New wideband microstrip antenna using log-periodic technique

A novel wideband microstrip antenna using a series-fed linear array of patch resonators in a log-periodic arrangement is described. A 9-element example gives good input v.s.w.r. and radiation control over a 30% bandwidth with better than 70% efficiency. The new array configuration gives wider bandwidth than single-layer or stacked microstrip patches combined with better efficiency than patches on lossy substrates or microstrip spirals.     

一种带有新型馈电结构的宽带印刷角锥四臂螺旋天线

本文提出一种新型馈电结构的印刷角锥四臂螺旋天线。通过采用柱面共形结构馈电网络,与传统四臂螺旋天线相比极大地减小了地板安装面积及改善了阻抗带宽和轴比带宽。S11小于-10dB的阻抗带宽可达39.7%,3dB轴比带宽约22%。测试与仿真结果吻合良好。     

Miniaturised CPW-fed circularly polarised corrugated slot antenna with meander line loaded

A novel CPW-fed circularly polarised antenna with corrugated structure and meander line loaded is presented. This antenna can achieve 44% size reduction compared to the conventional CPW-fed slot antenna. Predicted results are validated by experiment. The measured 3 dB axial ratio bandwidth and the 10 dB return loss bandwidth are 12.4 and 17.1%, respectively. The peak gain of the antenna is 4.0 dBi.     

具有谐波抑制功能的圆极化整流天线设计

设计了一款新型的具有谐波抑制能力的圆极化整流天线。在圆环缝隙天线的中心挖圆形孔,控制天线的谐振频带与抑制高次谐波。在缝隙的内边缘开两个半圆形槽,缩减天线的尺寸并获得圆极化辐射。倍压整流电路有效地提高了整流天线的输出直流电压。仿真结构表明,天线谐振带宽(VSWR＜2)为17.6％,圆极化带宽(AR＜3 dB)达到3.7％。整流电路在0 dBm的输入功率时,能达到59％的整流效率和1.7 V的直流输出电压。该整流天线可作为无源射频识别(Radio Frequency Identification,RFID)标签的整流天线。     

一种新颖的宽带圆极化单极天线

该文设计了一种新颖的宽带圆极化单极子天线,该天线采用微带馈电模式。天线由C型贴片和改进的地板组成,整个天线尺寸仅为25×25×1 mm3。通过在C型贴片上切角和在地板上增加三角形微扰结构,可以有效增加天线的阻抗带宽和轴比带宽。该文给出了天线的设计流程,从表面电流分布分析了圆极化天线的工作机理。加工了天线实物,并对其进行了测量。仿真和实测结果表明天线具有超宽的阻抗带宽和轴比带宽。天线的工作频带为4.35～12 GHz(相对带宽为93.6%),3 dB轴比带宽为4.15～11.8 GHz(相对带宽为95.9%)。测量了天线的辐射性能和增益特性,实测结果与仿真结果吻合较好,证明了该天线的有效性。该天线可以应用于超宽带无线通信系统和卫星通信系统中。     

Graphene Microstrip Patch Ultrawide Band Antennas for THz Communications

Future generation local communication systems will need to employ THz frequency bands capable of transferring sizable amounts of data. Current THz technology via electrical excitation is limited by the upper limits of device cutoff frequencies and by the lower limits of optical transitions in quantum confined structures. Current metallic THz antennas require high power to overcome scattering losses and tend to have low antenna efficiency. It is shown here via calculation and simulation that graphene can sustain electromagnetic propagation at THz frequencies via engineering the intra‐ and interband contributions to the dynamical conductivity to produce a variable surface impedance microstrip antenna with a several hundred GHz bandwidth. The optimization of a circular graphene microstrip patch antenna on silicon with an optimized return loss of ?26 dB, a ?10 dB bandwidth of 504 GHz, and an antenna efficiency of ?3.4 dB operating at a frequency of 2 THz is reported. An improved antenna efficiency of ?0.36 dB can be found at 3.5 THz but is accompanied by a lower bandwidth of about 200 GHz. Such large bandwidths and antenna efficiencies offer significant hope for graphene‐based flexible directional antennas that can be employed for future THz local device‐to‐device communications.