GPS接收机低噪声放大器设计

选用噪声系数较低的Agilent E-PHEMT ATF-54143晶体管,采用集总元件网络匹配方法,设计实现了一种GPS接收机前端低噪声放大器。通过运用Agilent公司的微波软件ADS进行设计、仿真和优化,在PTFE基板上制作实现了该放大器。实测结果显示,在1 520～1 600 MHz工作频带内,噪声系数<05 dB,小信号增益>16 dB,输入驻波比<2,输出驻波比<15。     

一种用于干涉型光纤传感器动态相移测量的J0-J1法

提出了一种用于干涉型光纤传感器动态相移测量的J0-J1法,实现了无源零差检测,而且信号解调算法简单,检测频带宽。详细介绍了该方法的基本检测原理,并对解调误差进行了理论分析与仿真,得出了系统能够检测的最大动态相移幅度与干涉仪的工作点允许变化的范围相互制约的结论。编写了实时的信号采集、处理程序,对某一干涉型光纤水听器探头的声压灵敏度进行了测量。在频带20~1300Hz上,平均声压灵敏度为-162dB(0dB=1rad/μPa),波动<±1.0dB,单频点500Hz的灵敏度变化<±0.5dB,与采用相位载波(PGC)调制解调法测量的结果基本一致,验证了J0-J1法的可行性。     

一种低相移衰减器

分析设计了一种低相移PIN二极管衰减器,其平均衰减相移量为0.25°/dB,工作频带为2.5～5.3GHz,在0dB和12dB衰减时,频带内各频率的相移量都在0.5°范围内,衰减0～10dB时的输入匹配性能优于10dB。     

基于悬置微带结构的无反射滤波器

通过悬置微带传输线结构进行了无反射滤波器的研究和设计。首先利用耦合线结构设计了中心频率为3.92 GHz,插入损耗为0.32 dB,在0.1～10 GHz内回波损耗超过11.6 dB,中心频率处超过38 dB的双端口无反射带通滤波器;又利用λ/4开路谐振器和λ/4短路谐振器作为滤波单元,设计了中心频率为4.25 GHz,回波损耗在1.5～6 GHz内超过11 dB,在中心频率处超过40 dB的双端口无反射带阻滤波器。所提出的这两款无反射滤波器具有无反射频带范围宽、工作频带内S₁₁衰减大、多层自封装等突出优点。     

微带型行波管外平衡器的计算机辅助设计和实验研究

利用微带电路作成的行波管外平衡器的理论研究和实验工作已经完成。为了进一步改进行波管的性能,本文对平衡器的设计计算方法进行了讨论,改进设计了一个单级平衡器,使在2.87.0GHz的频带内增益起落从11.6dB降为2.74dB。同时提出不对称增益特性的双级复式补偿平衡器的概念和方法,设计和研制了一个双级平衡器。利用计算机对微波电路参量进行了优选调整后,在2.57.5GHz的频带内,增益起落从13.6dB降为2.73dB。实验结果的变动量为5dB。     

一种新颖的Ku频段宽带微带天线阵的设计

文章设计了一种新颖的Ku频段宽带微带天线阵。该阵列的天线单元为分层结构,通过在馈线增加匹配枝节,上层贴片附加寄生单元,实现了宽频带性能。仿真表明,天线单元的相对阻抗带宽(S11<﹣10 dB)达到了17.2%,频带内增益大于8.4 dBi,四单元天线阵的增益大于15.1 dBi。     

5～12 GHz新型复合管宽带功率放大器设计

利用一种新型HBT复合晶体管结构设计了一款宽带功率放大器,有效抑制了HBT的大信号Kink效应。采用微波仿真软件AWR对电路结构进行了优化和仿真,结果显示,在5～12 GHz频带内,复合晶体管结构的输出阻抗值更稳定,带宽得到有效扩展,最高增益达到11 dB,带内波动<0.5 dB,在9 GHz工作频率时,其1 dB压缩点处的输出功率为26 dBm。     

圆极化微带阵列天线的设计

研究了圆极化微带阵列天线的设计方法。重点讨论了用双馈电正方形单元天线实现圆极化、高增益阵列天线的实现方法,并利用Ansoft HFSS 软件进行仿真分析,仿真结果显示,在工作频带内天线增益>13 dB,驻波<1.3,方向图E面波瓣宽度>33°,H面波瓣宽度>33°。     

0.05—50GHzGaAsMMIC分配放大器

Mi mix Broadband公司推出GaAs MMIC分配放大器,这种分配放大器可用作超宽带放大器或光纤调制驱动器。该放大器采用0.15μm栅长GaAsPHEMT器件技术,其覆盖频带为0.05—50GHz。该器件上述频带内的小信号增益为9dB,噪声系数5dB;其增益控制为15dB,1dB压缩点输出功率 9dBm。这种标号     

CMOS多频带低噪声放大器设计

提出了一种多频带低噪声放大器的设计方法,可用于集成多个频段于一部终端的通讯设备.它不同于以往的电路结构,而是由共栅极作为输入,与一个共源极MOS管构成两级放大器,并通过使用2 bit的控制信号控制电路中的MOS开关,以调节电路工作在900 MHz、1.7 GHz和2.4 GHz等三个不同的频带.电路使用先进的90nm工艺库进行仿真,结果显示各频带的增益均大于16 dB,噪声系数小于1.7 dB,三阶交调点IIP_3和1 dB增益压缩点分别大于-2.5 dBm和-15.5 dBm,电路同时具备了扩展并包含更多频带的能力.     

宽频带圆波导TE_(21)模耦合器的设计方法

给出了宽频带圆极化 TE2 1 模耦合器的设计方法 ,该方法适用于实际工程设计 ,2 0 %的频带内耦合损耗<0 .5 d B,VSWR<1.5 ,轴比 <2 d B。     

8-18 GHz介质板极化器的分析与设计

介质板极化器在天线设计中的应用非常广泛。从介质板波导形成圆极化波的原理出发,推导出差相移与波导传播常数的关系式。因此只需利用数值方法计算波导的传播常数,从而减小了仿真计算量。分析表明在818GHz超宽带范围内,方波导中插入介质板的圆极化轴比理论上只能达到2．03dB。文中提出介质板插入结合波导口径变形的方法使圆极化轴比小于1．53dB,驻波比小于1．23。对介质板波导的关键参数进行误差分析,得到加工误差对圆极化性能的影响小于2．5％。     

Circular waveguide-to-microstrip transitions

A new circular waveguide-to-microstrip transition consisting of a microstrip probe inserted in a circular waveguide has been developed. Experimental results show that the transition has an insertion loss of less than 0.05 dB, and a return loss greater than 20 dB in the frequency range 8.72-10.66 GHz. This design can easily be scaled to other frequencies     

Design and performance of the magnetic hybrid-mode horn

Design techniques are presented for a class of circular magnetic hybrid-mode (MHM) horns together with experimental results. In comparison with earlier techniques, this design method is simpler and more amenable to physical interpretation. The horns designed exhibit performance comparable to that of the corrugated horn except that they have an ohmic loss of 0.8 to 2.7 dB. However, it appears feasible to reduce the gain loss to less than 1 dB     

Analysis and design of a two-octave polarization rotator formicrowave frequency

The analysis and design of a 45° polarization rotator are presented. A two-octave frequency band is achieved with only three grids of strips, each rotated with respect to the previous one. Over this band the transmission loss is less than 0.5 dB, the circular polarization ratio is less than 2.0 dB, and the major axis of the polarization ellipse forms 45°±3° with respect to the linear polarization direction of the incident plane wave. The analysis method is an original scheme based upon the conjugate-gradient fast Fourier transform (CG-FFT) method to analyze periodic structures and the generalized scattering matrix method to study their connection. A comparison between numerical and measured data is presented     

Circularly polarized circular sector dielectric resonator antenna

A circular sector dielectric resonator antenna (DRA) with circular polarization and a single feed is investigated and demonstrated. The design utilizes the radius to height ratio and feed position of the circular sector DRA to excite two resonant modes that are spatially orthogonal in polarization and in phase quadrature. Experimental results are provided for the design and these demonstrate that the circular sector DRA produces circular polarized radiation with axial ratio less than 3 dB over a 10% bandwidth     

机载圆锥对数螺旋天线及两种馈电方式的研究

论述了机载圆锥对数螺旋天线及其两种馈电方式的设计方法.利用FEKO软件对圆锥对数螺旋天线和两种平衡馈电方式进行了优化仿真分析.结果说明,该天线的电特性能够满足实际工程应用要求.在此基础上,研制了天线实物样机,并对该天线实物样机进行了测试.测试结果表明该天线在2.5～8GHz的工作频率范围内,方向图3dB波瓣宽度为100°左右,轴比小于3dB,驻波系数小于2.测试数据说明该天线的测试结果和仿真分析结果吻合良好,同时也说明该圆锥对数螺旋天线具有宽频带圆极化及宽频带宽波束特性,进而说明该设计方法是有效可行的,并可以推广应用.     

The design of a mode selective directional coupler for a high power gyroklystron†

The design method of mode selective directional couplers from a transverse electric mode in a circular waveguide to the fundamental mode in a rectangular wave guide is presented in this paper. The design results for a TE₀₁ circular mode coupler intended for use in the output power measurement of a high power gyroklystron are reported; these results indicate that more than 50-80dB directivity and sufficient suppression of unwanted modes can be obtained with a coupler less than 07m in length. The effects of frequency and rectangular wave guide size on coupler parameters are also discussed in this paper     

一种新型宽波束圆极化微带天线的设计

设计了一种新型宽波束圆极化微带天线,该天线采用四探针馈电,馈电网络由威尔金森功分器和传输线移相器组成,使四个馈电探针的相位依次相差π/2,实现了右旋圆极化辐射。通过Ansoft HFSS仿真结果表明：该微带天线结构简单、极化纯度高、全向性能好、轴比小于3dB的圆极化带宽达到27.7%,高于一般的微带圆极化天线（轴比小于3dB带宽约为15%）。天线可以很好地满足GPS通信的技术要求,也可用于无线局域网。     

Spiral transmission-line baluns for RF multichip module packages

We describe a design method and lumped model for a circular spiral transmission-line balun. All lumped values are extracted from the geometric parameters of the balun. From simulation, the design parameters with well predicted characteristics are defined. The balun is fabricated using multi-chip module processing technology, which is suitable for integration in RF packages. Measurements show a wide bandwidth of 1.5-4.1 GHz and excellent balanced outputs. Amplitude imbalance less than 0.5 dB and phase imbalance less than 4° are achieved. The simulation results are compared with the measurement. The model captures all important properties of the balun with reasonably high accuracy