新型3 dB电桥的设计

针对450 MHz频段通信系统中3 dB电桥体积过大的情况,基于微波网络理论提出了一种方形微带线3 dB电桥实现方案.借助Agilent公司的ADS(Advanced Design System)软件完成了仿真设计,通过其内嵌的LAYOUT工具并结合PADS LAYOUT软件,设计制作了PCB版电路.实测结果接近仿真数据,各端口回波损耗低于-20 dB,端口间隔离小于-30 dB,均满足450 MHz中频、20 MHz带宽前馈线性功放模组的要求,而其版图面积只有传统环形电桥版图面积的8%.     

X波段宽带圆极化微带天线的设计与仿真

设计并仿真了一种在X波段工作的宽带圆极化微带天线,其结构为双层介质与空气结合,通过宽带环形电桥和W ilkinson功分器馈电,可使天线驻波带宽达83%,3dB轴比带宽达75%。     

800~2500MHz宽带3dB电桥设计

文章详细描述了一种特殊结构的宽带3 dB电桥的制作过程和预算,提出了一种近似带状线的宽带3 dB电桥设计方案.该方案可使电桥方向性更好、制作工艺更加简便,其带宽可达到800~2 500 MHz,可以承受较大的功率容量,体积小,新式结构使其实现了低插损、高方向性和宽频带,并且易生产、易调试.     

一种新型宽带环形电桥耦合器设计

传统四端口环形电桥耦合器的带宽只有10%到20%。为了获得更大的带宽,本文提出了一种改进型环形电桥耦 合器。通过额外增加一个隔离臂,新设计可以工作在整个W波段。在此基础上,本文在输入臂上加入了一个切角来改善 输出信号的隔离度。仿真研究结果表明,在75GHz 到110GHz,两输出信号的幅度不平衡度小于0.07dB,相位不平衡度小 于0.37 度。相比于未作切角处理的五端口环形电桥,新设计输出端口的隔离度在全频段内大于15.07dB。改进型耦合器 可以应用于W波段平衡调制器以及其他需要高输出隔离度的W波段功率分配系统。     

一种Ku波段固态功率放大模块的设计

文中介绍了一种Ku波段固态功率放大模块的研制思路,详细阐述了功率放大链路的组成方案,以及基于波导E面T型分支和H面波导裂缝电桥的混合式4路功分/合成网络的设计方法。制作了实物样机并进行了相关测试,结果表明模块在Ku波段14%的相对带宽范围内可实现大于130W的脉冲输出功率,合成效率大于90. 2%,验证了设计方法的正确性和有效性。     

KA波段模拟移相器的仿真设计

利用ADS2009仿真并设计了一种KA波段模拟移相器,其工作频段为19.6~21.2 GHz,工作带宽为1.6 GHz。在设计中采用skyworks公司的SMV2019变容二极管,以砷化镓陶瓷基片作为基板,金属金作为微带线的导体材料,并在设计中采用馈电分支线耦合器电桥模式,最终设计出一款最大移相能力为105.226°的连续可调的压控模拟移相器。     

微带180°电桥小型化及宽带技术研究简

微带180°电桥用途广泛,是微波电路中的基本元件。其研究方向主要为小型化和展宽带宽两个方面。本文对小型化微带180°电桥和宽带微带180°电桥研究现状进行了分析总结,并用奇偶模法分析了理想倒相器情形180°环形电桥特性,基于分析结果,提出采用理想倒相器、环特性阻抗取值、增加匹配段等展宽180°环形电桥带宽的方法。     

双圆极化共形相控阵天线研究

设计了一种基于十字缝隙耦合双圆极化微带共形相控阵天线。首先设计了微带天线单元,分析了天线各结构参数对天线性能的影响。通过电桥向偏馈于十字缝隙上的馈线馈电,实现等幅、相差90°馈电,电桥的两个端口分别获得旋向相反的圆极化信号。然后对天线单元进行了测量,结果表明天线轴比小于3dB 的带宽为16%,驻波小于1.5 的带宽 为17%,波束宽度大于87°。最后对5×5 共形相控阵天线进行了仿真与测量,结果显示天线可以扫描60°,适合用作载体共形的卫星通信天线。     

微带180°电桥小型化及宽带技术研究

微带180°电桥用途广泛,是微波电路中的基本元件。其研究方向主要为小型化和展宽带宽两个方面。本文对小型化微带180°电桥和宽带微带180°电桥研究现状进行了分析总结,并用奇偶模法分析了理想倒相器情形180°环形电桥特性,基于分析结果,提出采用理想倒相器、环特性阻抗取值、增加匹配段等展宽180°环形电桥带宽的方法。     

热敏电阻风速传感器的线性补偿

热敏电阻风速传感器的风速/电压曲线受到气体温度、湿度等的影响,呈现明显的非线性化.通过设计基于双恒流源的双臂电桥,与常用的惠斯登电桥进行比较.实验表明,双恒流源双臂电桥比惠斯登电桥能更好地补偿热敏电阻风速传感器的非线性关系,并获得较高的灵敏度.     

Compact EBG in-phase hybrid-ring equal power divider

A novel electromagnetic-bandgap (EBG) in-phase hybrid-ring equal power divider is described. Coupled with the closed-form analytical expressions for the EBG structure, a systematic technique of design is presented for the first time. Compared to the conventional hybrid-ring equal power divider, based on the 15-dB return-loss criteria, an increase in both the input and output impedance bandwidth of approximately 10% from a starting frequency of 2.5 GHz, and a phase error of 0.006/spl deg/ within the passband have been achieved for the proposed structure. The proposed in-phase hybrid-ring equal power divider, besides providing a much broader bandwidth and occupying a smaller estate area, also possesses good harmonic suppression characteristic.     

Broad-band uniplanar hybrid-ring and branch-line couplers

Novel uniplanar 180° and 190° hybrids suitable for MIC and MMIC applications are described. The uniplanar crossover hybrid-ring coupler using a coplanar waveguide (CPW) and slotline provides substantially improved amplitude and phase characteristics over a broad bandwidth compared to conventional microstrip hybrid-ring couplers. Experimental results show that the new coupler has a bandwidth of more than one octave from 2 GHz to 4 GHz with a ±0.4-dB power dividing balance and a ±1° phase balance. A uniplanar two-branch directional coupler using a coupled rectangular slotline ring has also been developed. CPW-to-slotline transitions using uniform and nonuniform CPWs or slotlines are also discussed. These transitions are uniplanar and simple to fabricate. No via-holes are needed for ground connections, and integration with solid-state devices is easy. A pair of broadband transitions using CPW shorts and slotline radial stubs is demonstrated with a 1-dB bandwidth of more than 5.2:1     

A new class of multisection 180° hybrids based on cascadablehybrid-ring couplers

A new class of multisection 180° hybrids is presented in this paper. It is based on the hybrid-ring coupler that has been reconfigured such that multiple sections can be conveniently cascaded together. The main limitations of the conventional hybrid-ring coupler are its limited bandwidth, large size, and the impracticably high-impedance levels required for large power-split ratios. These limitations are readily overcome using the multisection cascadable 180° hybrids. Simple design equations based on the scattering matrix and experimental verifications of the theoretical results for two-section 180° hybrids are presented     

Hybrid-ring power divider/combiner bandwidth enhancement by matching networks

A procedure for synthesizing matching networks (MNs) placed at the inputs of hybrid-ring power divider/combiners (HRPDCs) has been developed. It is shown that, with five-section MNs connected to the HRPDC inputs, the HRPDC bandwidth approaches its theoretical limit.     

一种新颖可控陷波特性的超宽带天线

设计了一种具有可控陷波特性的超宽带天线,有效抑制了超宽带通信系统与窄带通信系统之间潜在的干扰。该天线的尺寸仅为3.5 cm×3.5 cm×0.1 cm,使用微带线进行馈电,并通过在天线单元上加载支节,从而实现天线可控陷波特性。利用仿真软件HFSS对天线进行计算,对天线的阻抗、方向图特性进行仿真对比。仿真结果表明,天线在超宽带系统3.1 GHz~25 GHz工作频段内的电压驻波比（VSWR）小于2,在5.2 GHz~5.8 GHz频率范围内的滤波特性较好,有效降低了无线局域网系统对超宽带系统的影响,在工作频段内该天线的辐射方向特性和方向图特性都较为理想。     

一种改进的杠铃形超宽带天线

为了优化超宽带天线的阻抗带宽,提出了一种改进的杠铃形超宽带天线,通过增加阶梯形缺口及采用部分接地面从而改善超宽带阻抗匹配。测量结果表明,天线的输入阻抗带宽达74.7%（3.45~7.56 GHz）,同时数值仿真表明在y-z和x-z平面方向图呈对称分布。     

非对称十字孔双脊波导定向耦合器的设计

借鉴波导定向耦合器的设计原理,采用双脊波导的形式（本文采用标准双脊波导WRD650型号）设计大功率宽频带定向耦合器。由于双脊波导相比于矩形波导,最低模式的截止频率更低,单模工作的频带更宽,特性阻抗更低,所以采用双脊波导的形式比矩形波导在带宽方面更有优势。波导耦合器耦合方式有很多种,最常用的有小孔耦合和缝隙耦合,本文采用非对称十字孔耦合的方式,并与等孔径分布和切比雪夫分布的圆孔耦合比较来确定非对称十字孔耦合方式,在耦合平坦度、方向性方面有更好的改进。利用电磁仿真软件进行仿真对比其结果,通过一些具体措施改善双脊波导定向耦合器的性能,使定向耦合器的各种设计指标达到要求。     

一种带有新型馈电结构的宽带印刷角锥四臂螺旋天线

本文提出一种新型馈电结构的印刷角锥四臂螺旋天线。通过采用柱面共形结构馈电网络,与传统四臂螺旋天线相比极大地减小了地板安装面积及改善了阻抗带宽和轴比带宽。S11小于-10dB的阻抗带宽可达39.7%,3dB轴比带宽约22%。测试与仿真结果吻合良好。     

Analysis and Design of a 3 dB Tunable Lumped-Element Directional Coupler

An analysis of a 3 dB lumped-element directional coupler(LEDC)based on arbitrary terminal impedance is described numerically.To solve the conflicted requirement for broad bandwidth and small size in LEDC,a new structure of coupler is introduced,which can significantly improve bandwidth and whose size is only 3 cm×4 cm on the conditions of the frequency domain of 410 MHz to 490 MHz.The measure results are in good agreement with simulations despite the unexpected resistor loss.