火星表面散射光对太阳电池发电影响研究

火星表面存在大气,太阳光经过大气后,部分被大气吸收,部分光到达火星表面,形成直射光,还有一部分光被空气尘埃阻挡发生漫反射,形成散射光,地面反射的光也是散射光光源的一部分。直射光和散射光均会对火星车太阳电池发电产生影响。分析了火星探测漫游者(MER)任务中火星车太阳翼实际发电情况,调研了火星表面直/散光辐照数据,进行了地面直/散光辐照试验,并对上述三类数据进行比对,给出火星表面散射光对太阳电池发电影响的定量结果。     

一种平衡微带线-槽线馈电的新型引向天线

提出了一种结构紧凑的印刷引向天线,采用平衡微带线-槽线馈电,充分利用了空间,以减小馈电网络面积和天线尺寸.使用电磁仿真软件CST Microwave Studio(R)对天线的结构参数进行了优化设计,并根据仿真所得到的电流结果对天线的宽带特性和定向辐射特性进行了解释.测试结果表明,该天线在1.88～3.06GHz的频带内反射系数低于-10dB,相对带宽达到了47.3％.在工作频段内增益为4.0 ～ 6.3dBi,天线总体尺寸为0.34λ0 ×0.58λ0,其宽频带可以用于PCS/UMTS/WLAN等多个领域,而简单的结构和较小的尺寸对于组成阵列也是有益的.     

半圆环嵌套多频印刷天线

文章从多频天线的研究现状出发,提出了具有多频特性的半圆环嵌套天线,通过电磁仿真软件CST Microwave Studio？仿真研究了半圆环的外半径、宽度和嵌套数目对通频带的中心频率、带宽和通频带个数的影响;设计了可工作于24GHz、3．5GHz、5．2GHz以及5．8GHz四个频段的共面波导馈电的印刷单极子天线,在此基础上设计了平衡微带线馈电、以嵌套半圆环为辐射单元的对称振子天线,并制作了两种天线实物进行测试,实验结果与仿真吻合较好,验证了设计思路的正确性。     

共面波导-槽线馈电的引向天线

在对现有印刷形式的引向天线进行简单分析之后,文章提出了一种共面波导-槽线馈电的引向天线的设计方法。通过对共面波导-槽线馈电网络的馈电端口阻抗的仿真计算,解释了天线的带宽特性;在对有源振子和引向器的表面电流的仿真基础上,建立了该天线的三元对称振子阵列的辐射模型,该模型很好地解释了天线的定向辐射特性。仿真和实验结果表明,所设计的天线是一种性能良好的小型宽带定向天线。     

新型圆环嵌套多频印刷天线

提出了一种具有多频特点的新型圆环嵌套印刷天线,该天线由不同直径的圆环嵌套得到。通过电磁仿真软件CST Microwave Studip进行仿真研究,结果表明嵌套圆环的外径、宽度和嵌套数目可以对其通频带中心频率、频带宽度和通频带数目进行控制。设计出了具有2．4GHz,3．5GHz,5．2GHz,5．8GHz四个通频带的共面波导馈电的单极印刷天线和以平衡微带线馈电的对称振子天线。制作了天线实物并在微波暗室中进行测试,测试结果与仿真吻合较好,该天线具有近似独立的频率可控性和较小的尺寸,可用于WLAN和WiMAX等领域。     

正方形嵌套分形多频印刷对称振子天线

设计了一类具有正方形嵌套结构的新型分形多频对称振子天线.振子由一系列相似的正方形单元嵌套组成.天线能够同时工作于多个频率,这些频率涵盖了WLAN系统所要求的2.4 GHz/5.2 GHz/5.8 GHz三个频率,采用三维电磁仿真软件CST MWS(R)软件进行了仿真研究,得到了平衡微带线馈电的对称振子天线的模型.制作了...     

一种高透光和强屏蔽新型CNT 薄膜的研究

基于相关文献的模型,研究并设计了一种同时具备宽频带内高透光率和高电磁屏蔽效率的新型碳纳米管薄膜。通过改变薄膜的结构参数进行仿真并对出现的现象进行规律总结,得到最优化结构。实验结果表明,该薄膜在可见光波段的透光率达90%以上, 600~900THz 频段更高达95%以上, 而20GHz 处的屏蔽效率为78dB,10GHz 处的屏蔽效率达84dB。该实验结果优于目前国内外的最好水平,实现了较理想的高透光与强屏蔽兼备的电磁屏蔽薄膜的设计。同时,对薄膜在电磁波斜入射情况下的性能进行了仿真分析,为薄膜在曲面光学方面的应用奠定了实验基础。     

三角形嵌套多频单极印刷天线的仿真与实验

设计了一种三角形嵌套结构的具有四个频带的多频天线,该天线由三个三角形金属环和一个三角形金属片形成的辐射单元嵌套构成,四个单元共用一个顶点,可通过共面波导进行馈电。应用电磁仿真软件CST进行仿真分析,结果表明多频天线的频带个数、中心频点和带宽是由嵌套三角形的个数、高度和顶角角度控制,且各频点与相应单元的高度之间具有一致的规律。仿真设计了2.4GHz、3.5GHz、5.2GHz和5.8GHz四个频带的多频三角形分形嵌套单极印刷天线,并制作了天线实物进行实验验证。研究表明,三角形分形嵌套天线通频带可控性良好,且尺寸较小,易于制造,可广泛应用于WLAN/WiMAX等领域。     

Multiband printed monopole and dipole antenna with square-nested fractal

A kind of novel multiband antenna with square-nested fractal is proposed and designed, including printed monopole antenna and dipole antenna, which are nested with a series of similar square elements. The antennas can synchronously operate in multiple frequencies, covering the four required frequencies, 24GHz/35GHz/52GHz/58GHz, for WLAN/WiMAX application. The antenna surface currents are simulated by CST MWS, a three-dimension full-wave electromagnetic simulator, and the multiband operating mechanism has been explained from analysis of the simulation results. Then the models of the two proposed antennas fed by coplanar waveguide (monopole antenna) and balanced microstripline (dipole antenna), respectively, have been obtained. Finally, prototypes of the two antennas have been manufactured and measured in anechoic chamber. The results well match the simulation results, which verifies the feasibility of design idea. Moreover, these antennas are miniature and the design idea can be easily applied into other types of nested structure, the features of which make the proposed antennas have promising application in multiband fields.     

High-gain planar TEM horn antenna fed by balanced microstrip line

A printed TEM horn antenna with high gain fed by balanced microstrip line is proposed. The radiation part of the antenna consists of two symmetrical triangular metal slice branches printed on the FR-4 substrate with 15 mm thickness. The two branches are fed by balanced microstrip line. The antenna is simulated by software CST MICROWAVE STUDIO and the equivalent adopted dipole model is proposed to describe the radiation characteristic of the antenna. The simulation results indicate that the frequency range is from 164 GHz to 5 GHz with reflection coefficient less than -6 dB, and the typical gain value is 8 dB in the operating bandwidth. In order to improve antenna gain without influencing the bandwidth, the length of the dielectric slab should be extended appropriately in the main radiation direction. By extending the length of the dielectric slab appropriately in the main radiation direction, the antenna gain can be improved significantly without the influence on the bandwidth. Besides, a metal disc loaded in the radiation direction makes the gain in band be more stable. The prototype has been fabricated and measured in microwave anechoic chamber which is coincident with the simulation results. This antenna can be widely applied in the UWB field.