Support Vector Driven Genetic Algorithm for the Design of Circular Polarized Microstrip Antenna

In this paper, a hybrid soft computing method for designing specific microstrip antenna is presented. Evolutionary algorithm such as genetic algorithm (GA) is one of the promising ways of finding global optimum solution from a multivariate nonlinear feature space. Being a stochastic iterative algorithm, it requires much computation power when the function to be optimized is complex and time consuming. Various meta-modelling techniques such as neural network, response surface methods, kriging, etc. can be used to model the process under optimization in order to reduce the computational expenses. In this paper, we investigate one such technique – support vector regression (SVR) – to model the complex analytical process. The model, thus obtained, is used for optimization using genetic algorithms. This approach is demonstrated for the design of circular polarized microstrip antenna at 2.6 GHz band. The results of SVR model are compared with other meta-models generated with neural network and response surface methodology.     

Triple Band Annular Ring Loaded Stacked Circular Patch Microstrip Antenna

In this paper a novel structure of annular ring loaded stacked circular patch microstrip antenna is theoretically analysed to observe various parameters such as return loss, input impedance, gain, directivity and radiation pattern. It is found that antenna possess three band of operation which signify the compactness and multiband operation of antenna. The antenna is resonating at three operating frequencies 1.720, 2.950, 3.060 GHz. The proposed theory is verified by simulation using Ansoft’s HFSS and theoretical results are in good agreement with simulated results. The antenna is useful for multi-services operations such as WLAN, GSM, UMTS, and WiMAX services.     

基于遗传算法的微带天线阻抗匹配设计

根据传输线理论,结合遗传算法的全局搜索优势,提出智能阻抗匹配的微带天线设计方法.可自动匹配微带/带状线、同轴、共面波导、共面/异面双线等传输线馈电的天线单元,可显著减少宽带天线单元设计中的全波仿真计算量.利用该方法设计了带宽37％,驻波比不高于1.5的微带振子天线,仿真表明优化得到的S参数曲线与HFSS仿真结果基本吻合.本方法还可优化多端口激励的天线单元及相控阵的宽带宽角阻抗匹配.     

运用Ansoft HFSS设计圆极化微带天线阵

介绍了一种工作频率为2.43 GHz的圆极化四单元矩形微带天线阵的设计方法.通过对天线单元采用正交馈电激励起两个极化方向正交的、幅度相等的、相位相差90°的线极化波从而使天线单元获得圆极化波.在利用圆极化条件确定天线尺寸基础上,借助Ansoft HFSS仿真软件对天线进行了仿真,仿真结果和实验结果基本一致.     

Array Pattern Optimization for Steerable Circular Isotropic Antenna Array Using Cat Swarm Optimization Algorithm

In this paper the steerable isotropic circular array antenna is designed for reducing the side lobe level (SLL) using evolutionary optimization technique. The optimization techniques particle swarm optimization and cat swarm optimization algorithm are used to reduce the SLL as well as to steer the main beam in specific direction. In this design of steerable circular arrays the amplitude excitations are optimized. Obtained results show that the maximum peak of SLL of the resultant patterns are as per requirement. This paper present a good performance in the array factor response and suppressed SLL for different number of array elements with different steering angle of the main beam using evolutionary optimization technique.     

微粒群算法优化设计宽带微带天线

微粒群（PSO）算法具有概念简单、容易实现及收敛速度快等优点,离散二进制PSO是PSO在二进制空间的扩展。将离散二进制PSO算法与FDTD法相结合来优化设计宽频带微带天线,以矩形微带贴片天线为例,仿真结果显示,在将PSO算法中的微粒维数分别设置为20维和64维的情形下,通过对天线贴片形状的优化,天线的-10dB带宽由原来的4．4％左右拓宽至大约13．8％和14．5％,优化成效显著。     

Design and Optimization of Dual Band Microstrip Antenna Using Particle Swarm Optimization Technique

Dual-frequency operation of antenna has become a necessity for many applications in recent wireless communication systems, such as GPS, GSM services each operating at two different frequency bands. A new technique to achieve dual band operation from different types of microstrip antennas is presented here. An evolutionary design process using a particle swarm optimization (PSO) algorithm in conjunction with the method of moments (MoM) is employed effectively to obtain the geometric parameters of the antenna performance. In this article a PSO based on IE3D®? method is used to design dual band inset feed microstrip antenna. Maximum return loss is obtained at 2.4 GHz is ?43.95 dB and at 3.08 GHz is ?27.4 dB. Its bandwidth, of 33.54 MHz, ranges from 2.38355 GHz to 2.41709 GHz. Simulated and experimental results of the antenna are discussed.     

Miniaturized Microstrip Patch Antenna Array for ISM Band Using Complementary Split Ring Resonator

Wireless Personal Communications - These days patch antenna arrays are widely used in various communication systems. In this research design of miniaturized microstrip patch antenna array is...     

Circular Polarization in Defected Hexagonal Shaped Microstrip Antenna

A novel circular polarization (CP) design of a single-feed Hexagonal shaped microstrip antenna for enhanced antenna parameters is presented. The CP design is obtained by placing three isosceles triangular defects at proper locations in the hexagonal radiating patch as well as in the square ground plane. By adjusting one of the side lengths of the triangular defect, slightly longer or shorter than that of the others, two orthogonal near degenerate resonant modes for CP radiation are excited. Moreover, the 3 dB axial ratio bandwidth is surrounded by the 10 dB impedance bandwidth, to ensure that the antenna radiates CP waves in its impedance band. The antenna gain of the proposed antenna has increased by 5.34 dB (7.93 vs. 2.59 dB), as compared to the hexagonal microstrip antenna with triangular truncations in patch but without triangular defects in the ground plane having same substrate material, height and same radiating patch size and shape. Prototype antenna is fabricated for experimental evaluation. Simulated and measured results are in good agreement with each other.     

Triple Band Circular Patch Microstrip Antenna with Superstrate

A novel compact triple band slit cut circular patch antenna with superstrate is proposed; slits on the patch provide additional resonances. The superstrate (cover) of dielectric layer provides protection to printed circuit antenna from environmental hazards due to abnormal weather conditions. The slits add two resonances in the resonance of a circular patch to achieve triple band antenna for multi services. The dielectric superstrate or cover above the microstrip patch causes the change in fringing fields between the patch and ground plane. The change in fringing field is accounted to calculate the effective relative permittivity. The effective permittivity is considered to evaluate the changes in resonance frequency due to superstrate. The various parameters of the antenna have been investigated and the antenna is simulated on Ansoft’s HFSS software simulator. A prototype of antenna is fabricated to confirm the return loss by measurement using the Agilent Technologies’ N5230A PNA-L Network Analyzer. The proposed structure with superstrate possess triple band characteristics and provides protection from environmental hazards. The resonating frequencies of the bands are 7.3, 8.7 and 10.3 GHz. The analytical results are found in good agreement with the simulated results obtained by Ansoft’s HFSS and further confirmed by measurement. Antenna is worth for X band operations such as remote sensing, WPAN and military satellite communication and vehicular applications.     

CSRR Loaded Tunable L-Strip Fed Circular Microstrip Antenna

A tunable L-strip fed circular microstrip antenna on thick substrate with CSRR in the ground plane has been analysed and investigated. The antenna is analysed using cavity model and circuit theoretic approach for initial design and then simulated on IE3D simulation software. The antenna is made tunable with PIN diode which makes it to work in different configurations. Two diodes were used to implement a double annular slot, one annular slot and one split slot and CSRR in the ground plane. While other configurations of diodes provide bandwidth and radiation pattern diversity, CSRR provides size reduction of upto 13.31 % along with high gain directivity and radiation efficiency. A maximum gain of 8 dBi, directivity 8.3 dBi has been achieved in the respective band of operations. The antenna exhibits wideband along with multiband characteristic.     

宽带圆极化微带天线的设计

在传统圆极化天线的基础上,设计了一种宽带四元组合圆极化微带天线,采用双层电磁耦合馈电结构,不仅拓宽了阻抗匹配带宽,而且有效改善了天线的圆极化轴比特性。经过计算和测试,天线工作于Ku波段时,阻抗带宽和3dB轴比带宽分别达到了26.4%(VSWR<2)和8.64%。这种结构的圆极化天线在卫星通信等领域应用前景广阔。     

宽带圆极化微带天线的几种实现方法

在简要概述圆极化微带天线工作原理的基础上,重点介绍了目前国内外较为先进的圆极化微带天线实现宽带的多种方法,包括微带贴片天线、缝隙天线,以及采用PBG结构的圆极化天线。这些方法分别采用单点馈电,多点馈电或多元组合实现圆极化,均有效拓展了圆极化天线的阻抗匹配带宽和圆极化轴比带宽。参考一些实例验证了这些方法的可行性,然后展望了其可能的发展趋势。     

一种新型宽带圆极化微带天线的设计

X波段通信系统需要宽带圆极化天线,目前这类的研究很热门.介绍一种新型宽带圆形圆极化微带天线.该天线是基于空腔理论模型的设计方法,采用独特的切角结构,并用同轴馈电的方法,频率范围为8.25～9.28 GHz.在此讨论其展宽带宽和实现圆极化的理论与方案,描述所设计天线的3D结构,给出了设计仿真结果,数据显示驻波比带宽展宽到12%,轴比带宽为3%,表明了该设计能提高圆形微带天线的性能.     

一种新型Ka频段圆极化微带天线设计

提出了一种Ka频段圆极化微带天线的新设计,采用缝隙耦合馈电方式,通过在接地板开L型缝隙实现天线的圆极化工作。对天线阵列进行了仿真优化和加工实测,仿真和测试结果表明了设计的可行性。天线仿真和实测的相对阻抗带宽分别为3.9%和4.2%,仿真和实测的轴比相对带宽分别为2%和3.5%。天线具有良好的圆极化特性,可应用在卫星通信中。     

使用遗传算法简化设计矩形微带天线

讨论了矩形微带天线的传输线模型、遗传算法的编码方式、适应度函数的设计等,提出了一种利用遗传算法优化结果设计矩形微带天线的方法.利用反射系数,设计了简单的适应度函数,采用小规模的初始种群,加速了程序的收敛速度.仿真结果表明,遗传算法优化设计微带天线,可使反射系数小于-25 dB、增益大于5.5 dB.     

Multiband Multiple Elliptical Microstrip Patch Antenna with Circular Polarization

In this paper a compact low profile elliptical fractal patch antenna for high gain and multiband is presented which resembles Lorentz fractal shape. By introducing fractal on ellipse patch multiband applications are achieved. With the help of CST Microwave Studio Suite TM the proposed structure has been designed and analyzed. The simulated results are confirmed experimentally. The suggested antenna has a dimension of 40?×?55 mm² (L?×?W) and resonant frequencies obtained are 1.7, 3.2, 3.9, 5.9, 7.8, 8.6, 9.7, 11.4 and 12.6 GHz with VSWR?≤?2. The aerial is assembled on FR-4 (ε_r?=?4.4) substrate with thickness of substrate 1.6 mm. This antenna holds applications in many satellite communication transmissions, some Wi-Fi devices, cordless telephones, and weather radar systems.     

基于遗传算法的球面阵列旁瓣电平优化方法

针对共形球面天线阵列,采用有向天线阵元,在保持阵列孔径不变的条件下,以阵元分布位置作为优化变量,以降低最大相对旁瓣电平为优化目标,运用改进的遗传算法对阵列进行稀疏优化,仿真结果表明:该方法能够降低球形阵列的旁瓣电平,达到了减少阵元个数、降低天线系统成本的目的。     

一种新型S波段宽带圆形贴片天线的设计

采用HFSS11电磁场仿真软件设计和仿真了一种工作于S波段的新型宽带圆形微带贴片天线。天线采用聚四氟乙烯和空气两层介质,通过同轴探针顶部加载圆形金属电容片来对辐射贴片进行耦合馈电,由此补偿探针引起的电感;同时,在圆形贴片上开圆弧形缝隙,以生成第二个谐振点,从而进一步增大带宽。结果表明,天线的阻抗带宽达到了38%（VSWR〈2）,并且在带宽内天线的辐射方向图基本保持稳定。