共查询到18条相似文献,搜索用时 140 毫秒
1.
2.
3.
低轨通信卫星大容量、终端小型化要求卫星采用多波束天线技术来实现高增益、宽覆盖.本文针对低轨CDMA通信系统,设计了具有近"等通量"覆盖的平面阵列多波束发射天线,该天线由61微带单元天线阵、61个发射射频通道和数字波束形成网络组成;数字波束成形网络对输入的16个波束信号进行正交化、加权处理输出61路中频信号,由发射射频通道完成上变频和信号放大,最后通过天线阵辐射出去在空间形成期望的16个赋形波束覆盖.文章详细介绍了天线的实现方法和试验结果,通过对16波束发射天线原理样机的测试,结果表明天线各指标都符合设计要求,有效验证了天线系统设计的正确性. 相似文献
4.
5.
6.
7.
8.
针对传统方法设计的多波束反射阵天线增益低、波束偏移大、要求波束对称等问题,通过引入全局优化算法中的遗传算法对反射阵相位分布进行优化,以完成非对称多波束反射阵天线设计。为验证其有效性,设计并制作了一副Ku频段,波束指向分别为θ1=25°,1=0°和θ2=15°,2=180°的非对称双波束反射阵天线。测试和仿真结果较吻合,天线在中心频点的增益为26.03dBi,效率达到28.04%,1dB增益带宽和3dB轴比带宽均能覆盖11.3~12.3GHz(8.3%),实测波束指向为θ1=24.3°,1=0°和θ2=15°,2=180°,波束偏移0.7°。结果表明遗传算法能有效完成非对称多波束反射阵天线设计。 相似文献
9.
10.
提出了一种全数字波束合成(digital beam forming, DBF)体制卫星接收共形相控阵天线设计思路.该天线采用半球形共形阵排布方式, 阵元采用双层微带贴片天线实现宽带圆极化.在半球形的布局下, 通过判断卫星信号来波方向在球面上的投影来选择工作的阵元, 形成与来波方向一致的波束, 在全空域(—75°~75°)的仰角内可实现增益起伏小于1.5 dB的波束覆盖; 后端采用射频数字一体化设计技术, 可同时形成多个波束, 实现了一个天线跟踪多颗卫星的能力.最后加工和测试了天线样机, 验证了共形半球阵的波束形成能力.提出的天线设计思路有助于拓展数字波束体制在卫星通信中的应用, 对全空域多波束相控阵天线的研制具有指导意义. 相似文献
11.
针对5G大范围覆盖的应用场景进行了设计探讨,提出通过对基站天线垂直面进行余割平方成形、以保证大范围覆盖应用场景下信号的均匀性的方法。首先通过算法推导,证明余割平方成形的功率辐射波束可满足5G信号均匀覆盖的要求;其次,采用约束最优化方法,把天线的方向性系数作为目标函数,把指定区域的波束电平作为约束函数,求解基站天线辐射单元的权值,得到满足余割平方成形的辐射方向图。在MATLAB环境下开发了实现此算法的程序。本文的创新之处在于用实际的单元方向图和约束最优化方法,在保证天线增益最优的前提下,综合出需要线阵列天线方向图。引入仰角单元与其他正常单元一起综合方向图,解决顶盲问题,是这个方法的一个应用实例。最后,仿真验证该方法,并设置场景对应用余割平方成形的天线与常规天线的信号覆盖进行比较,证明该方法对信号均匀性有极大的改善。 相似文献
12.
13.
The design and performance of a Ku-band cylindrical antenna are described. The antenna is designed to provide a360deg azimuth coverage with 20 dB sidelobes and an operating bandwidth of 1 GHz (16.0-17.0 GHz). The antenna consists of 16 facets of2 times 4 dipole arrays. The360deg coverage is obtained with a switch matrix network. The antenna elements and the feeding switch matrix network are printed on a single printed circuit board. 相似文献
14.
Lincoln Laboratory has developed two circularly polarized VHF antenna systems for use on spin-stabilized satellites, Both are described, and test results are discussed. One is a low-gain (3-dB) antenna with omnidirectional coverage in the equatorial plane. The second is a high-gain (10-dB) antenna with a despun beam electronically scanned to always be Earth directed. Development of the component dipole and slot array elements is explained, and performance data are given for the final flight configuration. 相似文献
15.
A novel design methodology is presented for correlator antenna arrays in radio astronomy applications. In order to characterize the spatial-filter-like performance of a correlator array, an analyzer is developed to calculate its - coverage and synthesized beam, along with the capability to simulate the Earth rotation effect and the image retrieval process. On the other hand, particle swarm optimization (PSO) is applied to determine the locations of antenna elements in typical open-ended and closed array configurations (such as the ldquoYrdquo and the Reuleaux triangle), in order to achieve either the maximum - coverage or a synthesized beam with the lowest sidelobe level (SLL). Optimized arrays are observed to outperform uniform arrays and representative existing designs. 相似文献
16.
The radiation properties of a spherical phased-array antenna with circularly polarized elements are studied. Each antenna element is assumed to have a cosine type of field pattern. It is found that such an array is capable of providing complete hemispherical coverage without appreciable loss of gain. The radiation produced by the array stays circularly polarized in all directions, and the state of polarization is independent of beam steering. A special distribution of elements on a spherical surface is developed. This considerably suppresses the grating lobes in the pattern and thereby makes the antenna array broadband. Numerical calculations are made to determine the directivity and half-power beamwidth for the radiation patterns produced under various situations. 相似文献
17.
本文提出了一种适合高层建筑密集区域覆盖的智能天线结构和覆盖方法.针对不同高度和宽度的高层建筑可调整该天线的垂直面和水平面波束宽度,获得良好的覆盖区域;业务波束会随着业务终端所处不同楼层位置赋形跟踪.经过仿真验证表明,该天线和方法适合高层建筑密集区域覆盖,有利于节约资金和有效保证网络的深度覆盖. 相似文献
18.
The R.2R lens is a remarkable microwave device that provides perfect focusing, giving multiple simultaneous antenna beams from a circular or cylindrical array. However, the perfect focusing of the R-2R brings with it a serious limitation on angular coverage as a result of the angular doubling that enters when the array elements in the antenna are connected to the launcher elements on the lens periphery. We have now found a way to modify the R-2R concept so that a full circle of array elements can be mapped onto a full circle of beam ports. The new mapping makes use of hybrid junctions and either four or six physical lenses. The interconnections result in360deg of simultaneous antenna beams, each of which can be used both for transmission and for reception. 相似文献