排序方式: 共有120条查询结果,搜索用时 140 毫秒
51.
为克服无线通信中系统间的相互干扰,采用频带抑制技术设计了一种具有双阻带特性的超宽带单极子天线。首先采用共面波导进行馈电,辐射贴片和共面波导均为阶梯结构,使其在2.9~12GHz频带内电压驻波比小于2;其次在辐射贴片上分别引入C形和倒U形槽谐振结构,使其在3.3~3.9GHz和5.1~5.9GHz的频带内电压驻波比大于2;最后通过仿真与测量,验证该天线实现了良好的频带抑制功能。 相似文献
52.
本文设计一种共面波导馈电的超宽带天线(UWB),其阻抗带宽达到341%。所设计的天线印刷在尺寸为28×21×1.6mm3,介电常数为2.65的聚四氟乙烯介质基板上。并利用电磁仿真软件HFSS对影响天线性能的主要物理参数进行仿真、分析和优化,得到天线的理想尺寸。最后,对优化的超宽带天线进行制作,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,从而证明利用共面波导馈电的超宽带天线设计方法,能够实现兼容多种通信系统的可行性和有效性。 相似文献
53.
54.
We have investigated the power performance and scalability of AlGaAs/GaAs Double-Recessed Pseudomorphic High Electron Mobility Transistors (DR-PHEMTs) at 10 GHz on an unthinned GaAs substrate for CoPlanar Waveguide (CPW) circuit applications. It was found that the output power varied linearly with the logarithm of the device’s gate width ranging from 200 to 1000 μm. It increased at a rate of 0.01 dB/μm. That worked out to a doubling of output power (or 3 dB) for every 300 μm increase in the gate width. Gain decreased at a rate of about 0.005 dB/μm while PAE generally improved when the gate width was increased. As for DC measurement, the maximum transconductance of the device was about 375 mS/mm at VG = −0.5 V and VDS = 3 V. The gate-drain breakdown voltage (BVGD) measured was −20 V, defined at IG = −1 mA/mm. The microwave performance of the devices was measured on-wafer using a load-pull system at a bias of VG = −0.5 V and VDS = 8 V. For a device with a gate width of 1 mm, its saturated CW output power, gain and PAE value at 10 GHz was 27.5 dBm (0.55 W), 8 dB and 48%, respectively. At this same set of bias conditions, the value of ft and fmax was 40 and 80 GHz, respectively. 相似文献
55.
Zhou Xia Ji Wu Sheng Li Ying 《International Journal of Infrared and Millimeter Waves》2003,24(1):55-60
A space-domain integral equation (SDIE) which is solved using the method of moments is used to study the CPW discontinuities. And this paper attempts for the first time to use a fast, efficient computational method and leads to reasonable computation times. Good agreement has been found. The driving closed-form expressions and available models are useful in the design of coplanar circuits such as filters. 相似文献
56.
57.
用于短距离高速无线通信的超宽带天线,不仅要有较小的尺寸,还要求较小回波损耗和良好的全向性.环形开口共面波导馈电结构可增大电流路径、实现天线的小型化,叉形主辐射单元渐变结构使天线在全频段内、特别是高频段向各方向均匀辐射.仿真结果表明,天线在3.1 GHz~10.9 GHz频带内回波损耗小于-10dB、驻波比小于2,H面方向图直到9.5 GHz仍近似为圆形.天线结构紧凑,是一种高性能的低剖面小型化超宽带天线. 相似文献
58.
59.
为了解决传统CPW低通滤波器尺寸偏大、阻带较窄和插入损耗偏大的问题,采用 /4阶梯阻抗谐振单元(SIR)加载半圆形并联枝节(SISS)和缺陷地结构(DGS)单元的紧凑型结构设计了一个5阶CPW低通滤波器,分析了各单元结构参数对阻带性能的影响,引入微带线补偿方法对共面波导中心导体线特性阻抗进行局部补偿,改善了阻抗匹配性能,进一步降低了通带内的回波损耗和插入损耗。测试结果表明:该滤波器结构尺寸25mm×18mm,3dB截止频率3.5GHz,阻带范围3.8~17GHz。实现了CPW低通滤波器的低插入损耗、超宽阻带和小型化。 相似文献
60.
Ka波段22dBm氮化镓单片集成放大器 总被引:1,自引:1,他引:0
设计了CPW式Ka波段氮化镓单片集成放大器,并基于国内的GaN外延片和工艺完成了芯片的制备。据我们所知,这是国内首次报道的Ka波段氮化镓单片集成放大器。该单级集成放大器使用了一个栅长0.25μm,栅宽275μm的AlGaN/GaN HEMT。在Vds=10V连续波测试条件下,放大器的工作带宽为1.5GHz。其中在26.5GHz的线性增益为6.3dB,最大输出功率22dBm,最大附加效率9.5%。该MMIC所使用的AlGaN/GaN HEMT在Ka波段、Vds=10V条件下的输出功率密度达到1W/mm。 相似文献