一种L/C双频段盘锥和微带阵列的天线综合设计

设计了一种工作于L、C频段的复合天线，天线采用盘锥天线和微带阵列叠层复合设计。盘锥天线通过加载金属短路柱实现小型化和宽频化，在0.95～1.6 GHz辐射水平全向电磁波；微带天线采用2×2小型化阵列，在4.25～4.35GHz实现高增益定向电磁波辐射。该复合天线内嵌安装于金属腔体内，腔体直径为200mm，高度为26.5mm，易与蒙皮共形，能够同时满足L频段多种数据链功能和C频段无线电测高功能需求，可广泛应用于航空航天领域。     

单极X频段小型化天线的设计与互扰仿真

为满足船载测控设备海上标定、校验跟踪参数的需要, 一般采用放信标球的方式,同时为克服信标球在空中随气球旋转给跟踪带来的不利影响,信标天线必须采用组阵方式。由于信标球是一个小球体,安装位置受限,组阵信标天线在满足天线指标的情况下,必须满足小型化和良好互扰性要求。文中设计了一个小型化X频段天线,通过分析比较,最终采用短单极子结构,在垂直方向具有全向性。通过HFSS的仿真和参数参数优化,得到了结构参数和性能参数。通过单个天线性能仿真,以及天线组阵仿真的结果可知,所设计的天线指标上完全满足使用要求,具有天线结构紧凑、易于加工的优点;同时,本文所采用的建模、仿真方法、对其它相关天线设计也有一定的参考价值。     

一种全向圆极化天线设计

提出了一种基于四臂螺旋结构的新型全向圆极化天线设计方法。通过调整螺旋结构的螺距和直径实现天线的全向圆极化辐射,应用具有移相功能的微带功分器实现螺旋线馈电。对天线的各设计参数进行了分析和优化设计,加工了天线样机,实测结果与计算结果基本一致,在2.05GHz～2.2GHz频率范围内具有良好的全向圆极化辐射特性。     

GPS接受系统的研制和应用

介绍了对全球定位接受系统具体的工作原理,通过全球定位接受系统实验数据分析,系统精度及全向棒状天线全向方向性得到验证,采用与弹共形的微带天线,从而实现全球定位技术在弹道修正系统中应用。     

小型化低剖面全向滤波天线设计

设计了一个小型化全向微带滤波天线。天线由带通滤波器和微带天线组成,二者共用一个地平面以减小尺寸且采用缝隙耦合方式连接,带通滤波器蚀刻在微带贴片天线的馈线位置处,引入选频滤波功能,在输入馈线前端添加一个横向矩形贴片使整个系统达到良好的阻抗匹配。与传统的微带天线相比,所设计的滤波天线在不改变尺寸大小的基础上引入了选频滤波功能,在通带边缘体现出较高的选择性。仿真与测试结果表明,该滤波天线的阻抗带宽为2.31 GHz～2.56 GHz,且通带内增益平缓,平均增益约为2.1 dBi,在工作频段内呈全向辐射特性。     

一种新型的超宽带天线的研究

提出了一种微带馈电的超宽带天线。该天线印刷在覆铜介质基板上,介质基板尺寸为30 mm×35 mm×1.5 mm,材料是介电常数为4.4的FR4介质。利用仿真软件HFSS对天线参数进行仿真和优化。通过在微带面上开缝,可实现天线频带宽度(S11<-10 dB)2.5 GHz¹1.5 GHz,相对带宽达128%。结果表明,该天线不仅满足超宽带要求,而且结构简单,体积小,适合在UWB通信中应用。     

相位激励赋形多波束形成算法分析及仿真实现

数字波束形成是天线技术与数字信号处理技术结合的产物,是智能天线实现空分多址的关键技术.采用相位激励赋形多波束形成技术,给出了智能天线数字多波束形成的优化算法,利用该算法对均匀圆环阵天线各单元权值进行计算,仿真实现了均匀圆环阵天线多波束方向图,在不同方向上同时得到了多个波束.该算法计算复杂度低,空间隔离度好.阵元呈圆环状分布,具有全向搜索特性,克服了直线阵搜索的缺点.该方法还可用于任意单元构成的不均匀阵列天线,以及波束展宽和扇形波束的形成.     

一种小型WLAN双频天线的设计

为了适应无线局域网(WLAN)通信技术的要求,需要设计一种能够同时在高、低两个频段工作的小型天线,并且在工作频段内具有全向辐射性能.针对上述问题,设计了一副小型化WLAN双频天线.天线的辐射结构是由两个矩形贴片和一个倒锥形贴片组合形成,通过在天线辐射贴片中间加载一个圆环缝隙,从而实现了双频效果.和常规的双频微带贴片天线相比,天线的尺寸可以大大减小.仿真和实测结果表明,改进的天线单元达到了设计要求,验证了设计方法的有效性和可行性,具有十分良好的应用潜质.     

一种宽带天线的研究与设计*

为了满足宽带通信的需求,利用U形单极子天线和两个U形寄生辐射元的方法,设计了一种共面波导馈电的宽带天线,其阻抗带宽达到85%。所设计的天线印刷在尺寸为20 mm×30 mm×1.6 mm、介电常数为265的聚四氟乙烯介质基板上。为了满足无线局域网（WLAN）和全球互联微波接入（WiMAX）的工作需要,抑制不需要的信号,在U形单极子辐射元之间插入一条调谐微带线,产生一个陷波特性,使所设计的天线满足WLAN、WiMAX和低端UWB通信需求。利用高频结构仿真软件HFSS对影响天线性能的主要参数进行仿真、分析和优化,得到天线的优化尺寸,并对优化的天线进行制造和测试。实验结果表明,该天线比传统微带贴片天线性能有了较大的提高,证明了利用共面波导馈电和寄生技术设计宽带天线的可行性和有效性。     

一种新型RFID天线的仿真设计

为满足RFID天线小型化要求,提出一种基于LTCC技术的新型天线。仿真结果表明天线具有良好的全向性和宽频带特性,在2．4-2．5GHz频段反射损耗小于-10dB。本文还研究了介质常数等参数对天线性能的影响。     

Low-sidelobe marine radar microstrip array antenna based on hybrid algorithm and metamaterial

A microstrip array antenna with low sidelobe level (SLL) for X-band marine radar is proposed. The antenna is composed of a 32-element patch array and a three-layer near-zero-index metamaterial (NZIM). The IABC-Kmeans algorithm, which combines the improved artificial bee colony algorithm and K-means clustering algorithm, is used to optimize the current amplitude of the array elements to obtain a lower SLL. The NZIM is loaded in front of the array antenna to reduce the beamwidth of the E-plane. The antenna is designed and fabricated. The measurement results show that the gain of the antenna at the center frequency is 22.7 dBi, the SLLs of H-plane and E-plane are ?30.66 dB and ? 26.78 dB respectively, and the half-power beamwidth of H-plane is 5.9°. Compared with the previous similar antenna structures, the antenna has lower SLL under the premise of narrow beam and high gain, which is very suitable for X-band marine radar of small and medium fishing vessels.     

Wideband cavity‐backed log‐periodic‐slot end‐fire antenna with vertical polarization for conformal application

A 6–18 GHz wideband cavity‐backed log‐periodic‐slot end‐fire antenna with vertical polarization for conformal application is presented. The log‐periodic folded slots and parasitic slots with 10 slot elements are applied to cover 6–18 GHz frequency band and the log‐periodic metallic cavity is placed under each slot element to keep wideband performance and prevent the effects of large metallic carrier on radiation patterns. The ground plane etched with log‐periodic slots is reversed and touched directly to the backed cavity and a dielectric cover is added to the antenna, to further improve the antenna performance. Meanwhile, a broadband microstrip‐coplanar waveguide transition is inserted in the antenna for measurements. With these designs, the proposed antenna shows good impedance matching (|S₁₁|<27 dB) and end‐fire gain (>4 dBi) performances in 6–18 GHz. The proposed antenna also keeps low‐profile and easy flush‐mounted characteristic which is suitable for conformal applications of high speed moving carriers.     

On the effect of ground‐plane thickness on an aperture‐coupled dielectric resonator antenna

A hemispherical dielectric resonator antenna excited by a microstrip feedline through a narrow slot in a thick ground plane is studied theoretically and experimentally. A numerical method based on a combination of the spectral Green's function, modal Green's function, and the method of moment is used to investigate the input characteristics of the dielectric resonator antenna system. The effects of ground‐plane thickness on input resistance, resonant frequency, and impedance bandwidth of the dielectric resonator antenna are discussed. © 2000 John Wiley & Sons, Inc. Int J RF and Microwave CAE 10: 271–277, 2000.     

Stacked rectangular dielectric resonator antenna with different volumes for wideband circular polarization coupled with step‐shaped conformal strip

This paper presents a wideband circularly polarized broadside radiation characteristics by using stacked rectangular dielectric resonator antenna (DRA) with different volumes. In this designed antenna, the wide input impedance‐ and axial ratio (AR)‐bandwidths come from three factors: stacked rectangular DR with different volumes, stepped‐shaped conformal strip associated with microstrip line as a feed and different type of partial ground plane. Here, the orthogonal TE^x_δ11 and TE^y_1δ1 modes have been responsible for the generation of CP radiation in stacked rectangular DRA. Measured results show that the proposed stacked rectangular DRA with different volumes achieves input impedance bandwidth of 54.84% while AR bandwidth has been found to be 11.53%. The proposed antenna provides broadside right‐handed CP radiation pattern with gain ranges from 2.27–5.80 dBic and offers an average radiation efficiency of 89.48%, across the entire working bandwidth, respectively. Therefore, this antenna is very much useful for the ISM 2400 band applications.     

Cross‐polarization reduction of microstrip antenna using microwave absorbers

In this article, a metamaterial inspired microwave absorber is used to reduce the cross‐polarization (XP) level of the radiated wave in microstrip antenna (MSA). A microwave absorber unit‐cell has been analyzed and implemented to reduce the cross polarization (XP) level in a single element and a 2 × 2 microstrip patch array antennas. The antennas have been designed on a FR‐4 substrate of thickness 0.8 mm at 10.1 GHz center frequency. The 2 × 2 patch array antenna with and without the absorbers have been experimentally verified for the S11 parameter, the radiation pattern, and the XP suppression in H‐plane and a good comparison has been found.     

一种具有宽带双极化低散射特征的微带阵列天线

针对阵列天线宽带散射缩减设计进行研究,设计了一种基于无源对消技术的低散射阵列天线,该新型微带阵列天线在宽频带内具有双极化低雷达散射截面（RCS, Radar Cross Section）性能;对基于两种散射性能不同的单元组成阵列的RCS性能进行了理论研究,进行了单元的散射幅度和相位对阵列RCS的影响分析;提出了一种加载T型缝隙的新型微带天线结构,该单元结构的辐射性能与散射性能能够进行独立调控和综合优化,该单元与传统微带贴片单元具有相似的辐射特性,并可在宽频带（带内和带外）内与传统微带单元产生有效相位差;将传统微带单元和加载T型缝隙的新型微带单元组成4×4阵列天线,仿真结果表明,提出的阵列天线在3GHz～7GHz（相对带宽80%）频带内实现了同极化RCS缩减,在3.3GHz～7GHz（相对带宽71.8%）频带内实现了交叉极化RCS缩减,缩减峰值分别为16.3dB和36.3dB,带内RCS缩减均值分别为14.1dB 和17.6dB;与传统微带阵列天线相比,提出的阵列天线增益下降小于0.1dB;提出的微带阵列天线具有高效率辐射和宽频带双极化低散射性能,为低散射阵列天线设计提供了新的思路。     

A novel RF energy harvesting cube based on air dielectric antenna arrays

In this article, a new 2 × 2 circular microstrip antenna array with air dielectric layer for ambient RF energy harvesting has been proposed. Two pairs of arc‐shaped slots located close to the boundary of the circular microstrip patch have been designed for achieving dual‐band response and extending the frequency bandwidth. The antenna has a frequency bandwidth from 1.85 to 1.93 GHz and from 2.0 to 2.1 GHz which can cover GSM‐1800 and UMTS‐2100 bands. At the frequency of 1.89 and 2.05 GHz, the measured gain is 5.3 and 6.6 dBi, respectively, and high gain of 3.8‐9.3 dBi has been achieved over the whole band. Also, a broadband rectifier that can cover all the bandwidths of the antenna array is designed for the rectenna, which has the maximum rectifying efficiency of 53.6%. Finally, a cube device formed of four antenna and four rectifiers is designed to harvest RF energy, whose maximum output DC voltage is 2.3 V and the maximum output power is 4 mW that can drive four LEDs and an electronic watch.     

Fast simulation‐driven optimization of planar microstrip antenna arrays using surrogate superposition models

A technique for simulation‐driven design of excitation tapers for planar antenna arrays is presented. Our methodology exploits antenna array models constructed as a superposition of simulated radiation and reflection responses of the array under design, with only one radiator active at a time. Low computational costs of these models are ensured by using iteratively corrected electromagnetic‐simulation data computed with coarse meshes. Our technique allows for simultaneous control of the radiation pattern and the reflection coefficients of the array. Numerical efficiency as well as scalability of the technique is demonstrated using the design examples of various sizes and topologies, including a sixteen element and hundred element microstrip patch antenna arrays of the Cartesian lattice and a hundred element microstrip antenna array of the hexagonal lattice. The proposed technique is versatile as it also can be applied for simulation‐based optimization of antenna arrays comprising other types of individually fed elements, e.g., wires, strips, or dielectric resonator antennas. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:371–381, 2015.     

Hybrid two segments ring dielectric resonator antenna for ultrawideband application

In this article, a hybrid two segments ring dielectric resonator antenna with partial ground plane, for ultrawideband application is described. The proposed antenna structure consists of annular shape microstrip line along with two ring dielectric resonators having different permittivity. By applying the combination of shifted annular shape microstrip line (used as a radiator as well as to convert TM_01δ mode to TE_01δ mode) and two segments ring dielectric resonator, ultra wide bandwidth has been achieved. Prototype of proposed structure has been fabricated and tested. Measured results show good agreement with the simulated ones. The proposed antenna structure operates over a frequency range of 3.45‐10.9 GHz with a fractional bandwidth of 103.83% and having better gain and radiation characteristics. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:47–53, 2016.     

An improved method of designing optimum microstrip Rotman lens based on 2D‐FDTD

In this article we propose an efficient method for analysis of microstrip Rotman lens using two‐dimensional finite difference time domain (2D‐FDTD). Both the dielectric and conductor losses are modeled in this method in order to achieve results which are in good agreement with 3D simulation. Using 2D analysis, the required simulation time is reduced considerably, which in turn, enables us to use the proposed analysis method in an optimization procedure. Based on this optimization procedure, we present an improved design of a microstrip Rotman lens in which both the efficiency and also the gain of isotropic antenna array are increased. In this design, the Rotman lens has 5 beam ports and 16 array ports and operates in Ku frequency band.