米波警戒雷达天线小型化研究

分析了单元间距较大的小型天线阵的基本特性，探讨了这种天线阵的设计方法，设计了一个小型大间距八木阵，试验结果表明，这种天线阵增益高，波瓣性能好，是米波警戒雷达天线小型化的有效途径之一。     

电小尺寸锥台上双馈圆极化共形微带天线阵设计

在电小尺寸锥台上,设计并实现一款锥台共形水平全向双馈圆极化微带天线阵。该天线的工作频率覆盖GPS L1频点(1.575 GHz)和北斗导航系统B1频点(1.562 GHz)。基于HFSS软件仿真,分析了锥台共形对天线阵单元的S11、轴比和增益等参数带来的影响,通过调整辐射贴片尺寸,减小了锥台共形对天线的影响,改善了圆极化性能,提高了天线的圆极化增益。加工天线阵并进行测试,测试结果表明,该天线阵在1.55～1.60 GHz频段内,S11参数≤-10 dB,在GPS L1频点和北斗B1频点,水平全向增益最大值达到了1.73 dB,1.25 dB,增益不圆度≤2.5 dB,实测结果表明该天线具有良好的水平全向圆极化辐射性能。     

Ku波段一体化开口脊波导阵列天线

设计了一种集成内校正通道的Ku波段一体化开口脊波导阵列天线,由底部的同轴连接器馈电,经渐变阶梯状的过渡匹配段同轴波导变换,并压缩波导截面尺寸以实现宽带二维宽扫性能。在开口脊波导底部设置耦合槽和校正波导,形成内校正通道,并将馈电连接器偏置,使一条校正波导可以耦合相邻的两列天线单元,实现了高集成度一体化设计。设计制造了8×8单元的天线阵面,实测结果表明,该天线驻波小于2的相对带宽为14%,可实现二维±60°的宽角扫描,天线增益约21.8dB,辐射效率81.7%。该天线具有宽带、二维宽扫、结构紧凑、高集成度等优点,且实现了小单元间距相控阵天线的内校正功能。     

超宽带平面天线阵列的微带馈电

设计、分析、制作了3种类型的4单元平面超宽带天线阵列,采用宽度按指数渐变的微带线网络馈电,馈电网络和天线单元设计在同一介质基板上,易于加工和集成.给出了天线单元、馈电网络各自的输入特性,并将其与整个阵列输入特性进行了比较.仿真和测量结果表明:这3种类型的天线阵在3.1～10.6 GHz绝大部分频段内的回波损耗小于-10 dB,最大不超过-8 dB,天线阵的增益在8～12 dB之间,远大于单元的增益.     

高增益宽带圆极化微带天线阵研究

研究了S波段高增益宽带圆极化天线阵的设计方法,讨论了阵列间距与天线增益、E面方向图之间的关系,论述了微带天线阵馈电网络工程实现途径,并研制了S波段高增益宽带圆极化天线阵实验样机,并对天线阵实验样机的电特性进行了测量,测量结果表明,天线最大增益为15 dB时,天线阵的阻抗带宽达到了12.25%,圆极化轴比小于3 dB带宽为9.4%,测试数据充分说明了该天线阵具有尺寸小、高增益、宽频带、圆极化特性,从而验证了设计方法的有效性.     

电小尺寸锥台上单馈圆极化共形导航天线阵设计*

在电小尺寸锥台上,设计并实现了一款工作于GPS L1 频点(1.575GHz)和北斗B1 频点(1.562GHz) 的锥台共形水平全向圆极化微带天线阵。采用HFSS 软件仿真,比较分析了锥台共形对贴片天线阵单元S11 、轴比、 增益等参数带来的影响,通过对辐射贴片尺寸调整,改善其圆极化性能,提高了圆极化增益。加工实物天线阵样机, 测试结果表明,该天线阵在1.556 ~1.578 GHz 频段内S11<=-10dB,在GPS L1 频点和北斗B1 频点处,水平全向增益 最大值分别为2.08dB 和1.19dB,增益不圆度小于2dB,实测结果证明该天线具有良好的水平全向圆极化辐射性能。     

一种宽带小型化相控阵天线单元的研究

设计了一种可用于工程化实际生产的宽带小型化相控阵槽线天线单元,其天线单元采用与半波阵子相结合的槽线天线馈电形式,可工作于400 MHz～ 900 MHz的带宽之内.天线单元的横向和纵向尺寸只有大约0.2个最低频工作波长,符合天线小型化的需求.仿真结果表明:该天线在2.25倍的工作带宽之内匹配和辐射特性良好,具有体积小、剖面低、频带宽和结构简单等特点,可以作为宽带小型化相控阵天线单元.     

一种S波段宽带微带贴片天线阵列的设计

介绍了一种宽带微带贴片天线单元及2元阵列的设计方法,天线工作的中心频率为rl_5OHz（S波段）。天线单元设计中采用口径耦合理论和层叠贴片天线结构,有效增大了天线的阻抗带宽。仿真结果表明该天线阵列实际增益达到11．9dB;在2．27～2．78GHz频率范围内端口驻波比小于2,相对带宽为20．4％;交叉极化电平为-31dB,证明该天线阵具有宽频带、低交叉极化等优良性能。     

一种X波段宽带背腔微带天线阵面设计

文章介绍了一种X波段宽带、宽扫、背腔式微带天线阵面。该天线利用背腔式口径耦合馈电的方式使单层微带板贴片单元实现了阵面中小单元间距下天线的宽带性能,并结合探针式天线单元级独立馈电的方法,实现了天线阵面的大角度扫描功能。基于项目需求,设计加工了一套8×8单元天线阵面,测试结果表明:该天线在X波段21%的相对带宽内驻波优于1.8,可在方位向实现±45°的大角度扫描,天线效率达到了80%以上,满足了项目的电性能指标要求。     

一种北斗多模小型化抗干扰天线阵列设计

文章设计了一种用于北斗卫星导航的多模小型化抗干扰天线阵列。阵列包括北斗RNSS B3、RDSS S双频阵列及RDSS L频点天线单元,采用叠层双馈微带天线阵元及陶瓷介质基底,有效减小了天线口径。通过仿真分析,天线阵列驻波、极化增益性能良好,能够应用于小型化高性能北斗接收设备。     

Evolutionary optimization for pattern synthesis and reduction of mutual coupling of linear antenna arrays

Optimal design of antenna arrays to minimize the mutual coupling effects in the geometrical arrangements of the linear antenna array (LAA) and circular antenna array (CAA) is dealt with in this work. Two different cases are considered to reduce the effect of LAA and CAA: Case‐1 in which the current excitations of the antenna array are considered to get the optimal radiation pattern of two geometry called LAA and CAA and Case‐2 in which inter‐element spacing and current excitations are both optimized for LAA geometry. A cost function that involves the mutual coupling factor as an optimization factor is developed to reduce the side lobe level (SLL), which takes mutual coupling effects into consideration. Excitation values and inter‐elemental spacing are optimized using particle swarm optimization (PSO). In LAA, for 8‐, 12‐, 16‐element arrays, SLLs are reduced by ?15.52, ?16.71, and ?17.78 dB in Case‐1. For the same sets of element arrays, SLLs were reduced by ?17.35, ?19.71, and ?20.26 dB in Case‐2. In CAA, the current excitations of the antenna array are optimized. For 8‐, 12‐, and 16‐ element arrays, SLLs are reduced to ?7.405, ?10.52, and ?9.43 dB, respectively. The arrays coded with the help of MATLAB based computation and the results obtained by MATLAB are validated by using CST.     

Grating Lobe Suppression of Narrow-Wall Slotted Hollow Waveguide Millimeter-Wave Planar Antenna for Arbitrarily Linear Polarization

A high-gain and high-efficiency slotted waveguide planar antenna is developed in the millimeter-wave band. Forty-five degree inclined polarization is required for automotive radar systems. In the design of slotted waveguide array for arbitrarily linear polarization, slot spacing is one guide wavelength which is larger than a wavelength in free space. Consequently, grating lobes appear in the radiation pattern. So, we developed a slotted waveguide planar antenna composed of post-loaded narrow-wall slots and a single-layer alternating-phase feeding circuit. A planar antenna with suppressed grating lobes has been fabricated and its RF performance has been measured. The measured gain is 33.2 dBi and antenna efficiency is 56% at 76 GHz. Grating lobe level is -28.6 dB lower than main lobe level. Since the proposed structure remains simple, the antenna is expected to be manufactured by metal injection molding for low cost     

W波段45°线极化天线阵设计

提出了一种带反射相消单元的W波段45度线极化微带贴片天线阵列.单列串馈天线阵采用泰勒加权结合反射相消单元实现了25dB的旁瓣抑制,通过添加贴边矩形槽改善了主瓣内的交叉极化.一阶十路功分器通过T型结取代一般的四分之一波长匹配段实现4.5倍的不等功分比.仿真与实测结果表明：组阵后的天线工作在75.7GHz~77.6GHz,水平和垂直方位3dB波束宽度可覆盖正负45度,该宽度内交叉极化比均高于18dB.天线增益达24dB,旁瓣抑制度达20dB.该天线形式可用于汽车防撞雷达并提高其抗干扰能力.     

A multi-objective approach in the linear antenna array design

We show that linear antenna array design can be modeled as a multi-objective optimization problem. A genetic algorithm is proposed for the solution of this problem. This genetic algorithm efficiently computes the trade-off curve between main beam width and side lobe level for linear antenna arrays with uniform and non-uniform separations. For uniform separation, the proposed algorithm is validated against the Chebyshev method for the cases of 6-, 8-, 10-, and 12-element linear arrays. Simulation results for non-uniform spacing with uniform and non-uniform excitations applied across the array indicate that the trade-off curve between main beam width and side lobe level for uniform spacing arrays can be improved by introducing non-uniform spacing.     

Performance of Smart Antenna Under Different Fading Conditions

Optimizing the current distribution of an evenly spaced antenna array has shown to be an efficient approach for reducing side lobe levels. In this article, the Tchebyscheff distribution-based antenna array synthesis approach is combined with an adaptive signal processing algorithm for beamforming and side lobe level reduction in smart antennas in various fading situations. The performance of smart antennas in uniformly spaced linear, planar, circular, and semi-circular arrays are evaluated. The presence of Rayleigh and Rician channels is examined in the network. The least mean square (LMS) and normalised least mean square (NLMS) algorithms are applied as adaptive algorithms. In fading environments, the NLMS algorithm with Tchebyscheff distribution outperforms than the LMS algorithm with Tchebyscheff distribution, with a side lobe level decrease of 11.23 dB. The lowest side lobe achieved with the NLMS algorithm with Tchebyscheff distribution is???45.59 dB for uniform planar array.

     

基于NUFFT方法的二维非周期阵列天线方向图计算

相控阵天线应用在有限电扫描角度时,采用大间距体制以减少有源通道数量,降低天线成本。由于单元间距大于波长,在可视空域内会出现栅瓣,常采用非周期排列方法分散栅瓣能量降低栅瓣电平。文中提出了一种变距平移错位抑制大间距阵列栅瓣的方法,并介绍了基于二维NUFFT计算该非周期排列阵列天线方向图的方法。分析了影响该算法精度的因素,并通过在拟合虚拟阵列幅相值时通过采用局部坐标系有效减小计算量。通过一个由300个单元组成的非周期阵列方向图计算,对二维NUFFT方法以及累加法进行对比。前者的计算时间仅为后者的0. 9% ,验证了算法的高效性。计算结果显示全空域方向图吻合度高,方向性系数误差仅0. 05 dB,最高副瓣误差仅0. 12 dB,验证了算法的准确性。     

Dual polarization stacked microstrip patch antenna array with verylow cross-polarization

This paper describes the development and performance of a wideband dual linear polarization microstrip antenna array used in the Danish high-resolution airborne multifrequency polarimetric synthetic aperture radar, EMISAR. The antenna was designed for an operating frequency of 1.25 GHz±50 MHz and was built as an array of 8×2 probe-fed stacked microstrip patches. The feeding network is constructed in microstrip and is capable of handling 6 kW of peak input-power at an altitude of 45000 ft (unpressurized). The impedance bandwidth (return loss better than -14 dB) of the antenna is 10%, the isolation between the horizontal and the vertical ports of the array is 50 dB and the cross-polarization suppression is 40 dB. A new design principle for simultaneously achieving very low cross-polarization and low side lobes in dual linear polarization antenna arrays has been applied     

新型X波段波导缝隙阵列天线的设计

为了克服传统波导缝隙阵列天线重量大、副瓣偏高等问题,提出一种小型化、低副瓣X波段波导缝隙阵列天线的设计方法。首先采用高斯分布实现其幅度加权,快速完成低副瓣波导缝隙阵列天线的设计;然后结合HFSS 软件对传统压缩波导的窄边尺寸进行优化,减小窄边尺寸;同时采用3D 打印技术制造ABS 塑料波导缝隙框架和金属电镀工艺实现天线的加工,通过仿真分析和实物加工测试验证了所设计天线的有效性。所设计的天线方位面副瓣电平可达到-25 dB 以下,重量从25 kg 减小到2.5 kg,减重比达到了90%。最后,详细分析了不同金属电镀层厚度对天线性能的影响。     

Hybrid MUSIC Dolph–Chebyshev algorithm for a smart antenna system

This paper presents practical design of a smart antenna system based on direction‐of‐arrival estimation and Dolph–Chebyshev beam forming. Direction‐of‐arrival estimation is based on the multiple signal classification algorithm for identifying the directions of the source signals incident on the sensor array comprising the smart antenna system. The smart antenna system design involves a hardware part, which provides real data measurements of the incident signals received by the sensor array. This paper presents the Dolph–Chebyshev method for the synthesis and design of antenna arrays with periodic element spacing. A Field‐Programmable Gate Array implementation is presented for an antenna array application employing digital beamforming. The array comprises 10 elements, equal in number receiving radio frequency and intermediate frequency components, as well as a Spartan‐3E Field‐Programmable Gate Array‐based unit, which is responsible for the control of the array. Low‐cost and switched‐beam, and fully adaptive antenna array suitable for 2‐GHz applications are proposed in this paper. Copyright © 2013 John Wiley & Sons, Ltd.     

一种超宽带、大扫描角Vivaldi天线阵列

设计并加工测试了一款双面Vivaldi天线.通过结构优化, 提高了馈电效率和阻抗带宽, 并在组阵后显著降低了阵元间的互耦.实测结果表明该天线可以实现在2~8 GHz的频带内回波损耗(Return Loss, RL)小于-10 dB, 平均增益大于5 dBi.并采用“交错排列”的思路, 将所设计的双面Vivaldi天线组成超宽带阵列.此种方式可以有效解决天线尺寸和最佳阵列间距之间的矛盾, 进而抑制栅瓣, 增大波束扫描角范围.仿真分析表明, 在4~6 GHz时, E面交错阵列比普通一维阵列的扫描角范围提高20°左右.