Broadband microstrip branch-line coupler Broadband microstrip branch-line coupler

The design and measured performances of a broadband branch-line coupler are presented. The broadband coupler was designed by using a four-section branch line topology with a structure of the defected ground. Such a structure can make the impedance of the microstrip line much larger than that without defected structure, even using a normal PCB process. More than 231 Omega was easily achieved by such a defected structure. The measured performance of the broadband coupler agrees well with the results from simulation     

Broadband microstrip directional coupler

A nonuniform microstrip directional coupler with sinusoidally modulated coupling function is presented. The ripple and the amplitude response are controlled by the index of modulation m and the periodicity P of the function. For demonstration, a 20 dB ± 6% coupler is constructed on two different substrates and the experiment shows much flatter coupling response than the uniform or exponential line directional couplers.     

宽带微带正交耦合器设计

文章设计了一款微带线型宽频带微带正交耦合器。该正交耦合器由一个威尔金森功率分配器和一个宽带移相器级联组成。数值仿真结果表明该正交耦合器具有良好的宽带特性,它在50%以上的频带(S11≤–15 d B)上具有良好的阻抗匹配、功率分配(-3 d B)和90°移相(相位偏差为3°)功能。所以该正交耦合器必在宽带圆极化天线方面具有广泛的应用前景。     

一种新型S波段高平均功率宽带速调管

该文介绍了一种新型S波段高平均功率宽带速调管的主要设计思想、模拟计算结果和实验结果。文中提出了具有理想高频通过率的高平均功率宽带速调管电子光学系统的验证方法,以及联合使用2.5D Arsenal-MSN code和KLY6两种软件去除带内功率凹点和改善高频性能的方法。最终的实验测试结果表明,这些方法是有效的。     

S频段多模式应答机的设计

随着测控系统的不断更新,设计实现兼容多种测控体制的应答机非常必要.介绍了S频段多模式、多功能、宽频段应答机的设计方案,论述了其中的关键技术和工作原理.该应答机在扩频模式和调相模式下具有测距、测速、解调遥控指令和发射遥测副载波的功能,相比以往的S频段应答机方案,具有电路简化、功能较多的特点,因而能适应多种测控工程.     

S波段大功率宽带速调管车载发射机的设计

车载雷达对发射机的体积、重量和环境适应性提出了严格要求.文中介绍了一种具有较强环境适应性的大功率宽带速调管车载发射机的设计,叙述了发射机的主要技术指标和系统组成.重点介绍了高压电源、固态调制器、结构与冷却和宽温下带内输出功率的稳定性.最后,展望了多注速调管在大功率发射机中的应用前景.     

一种新型S波段宽带圆形贴片天线的设计

采用HFSS11电磁场仿真软件设计和仿真了一种工作于S波段的新型宽带圆形微带贴片天线。天线采用聚四氟乙烯和空气两层介质,通过同轴探针顶部加载圆形金属电容片来对辐射贴片进行耦合馈电,由此补偿探针引起的电感;同时,在圆形贴片上开圆弧形缝隙,以生成第二个谐振点,从而进一步增大带宽。结果表明,天线的阻抗带宽达到了38%（VSWR〈2）,并且在带宽内天线的辐射方向图基本保持稳定。     

Broadband overlaid inset dielectric guide coupler with very flatcoupling

In this paper overlaid parallel coupled inset dielectric guides are proposed for broadband applications to directional couplers. This structure provides much flatter and higher coupling than the conventional one without an overlay. The propagation and coupling characteristics of the coupled guides are obtained by using the integral equation formulation and Galerkin's procedure. Numerical results for two limiting cases are compared with available measured data, showing good agreement. Effects of thickness and dielectric constant of the overlay are examined on coupling and bandwidth. It is found that by suitable choice of these parameters very flat coupling can be achieved for a wide frequency range which is still within the fundamental-mode bandwidth. Examples of couplers with the bandwidth exceeding 45% for the coupling of 3±0.25 dB are presented     

Broadband circularly polarised slot loop antenna fed by three-stubhybrid coupler

A microstrip slot loop antenna with a three-stub hybrid coupler feed network is proposed for generating broadband circular polarisation. A very broad bandwidth of 55.6% at 2:1 VSWR and 22.2% bandwidth for <3 dB axial ratio was achieved     

玻璃基离子交换型宽带22 3dB耦合器研究

为满足2N光功率分配器的制作和应用的需求,对宽带集成化22 3dB耦合器进行了深入的理论和实验研究。采用3-D光束传播法,对传统的非对称X结进行了模拟改进,设计了低损耗且具有较宽工作带宽的22 3dB耦合器。采用Ag+-Na+离子交换技术在玻璃基上成功制作了非对称X结结构的宽带22 3dB耦合器。通过对1260nm~1360nm和1460nm~1600nm两个波段宽带光源的光谱测试,得到在宽带范围内小于4.0dB的插入损耗,光谱谱线相对平坦,波长依赖性较小,均匀性小于0.5dB。结果表明,采用这种非对称X结并结合离子交换工艺,可以在玻璃基上制作出宽带的22 3dB耦合器,这为进一步优化器件性能,研制成功具有应用价值的器件奠定了基础。     

基于非对称双芯光子晶体光纤的宽带定向耦合器研究

A novel broadband directional coupler based on an asymmetric dual-core photonic crystal fibet(PCF)is proposed.The asymmetry in the fiher is introduced by the enlargement of one air-hole in dual-core PCF.Numerical investigation demonstrate that broadband directional coupling with spectral width as large as 370 nm and polarization-dependent loss and uniformity lower than 0.2 and 0.5 dB,respectively,can be achieved.In addition,the proposed fiber shows large tolerance to the variation of the fiber parameters.In particular,the fiber length allows at least 10%derivation from the proposed fiber length of 7.7 mm.     

Broadband (7?18 GHz) 10 dB overlay coupler for m.i.c. application

A 10 dB m.i.c. coupler with dielectric overlays was successfully developed by a systematic design approach for opeartion in the 7?18 GHz frequency band. The design, fabrication and evaluation procedures for this coupler are described explicitly to enable accurate reproduction of the device.     

S波段雷达接收机前端低噪声放大器

采用0.35μm SiGe BiCMOS工艺设计了用于S波段雷达接收机前端电路的低噪声放大器。对于现代无线接收机来说,其动态范围和灵敏度很大程度上都取决于低噪声放大器的噪声性能和线性度。相对于CMOS工艺来说,SiGe BiCMOS工艺具有更高的截止频率、更好的噪声性能和更高的电流增益,非常适合微波集成电路的设计。该低噪声放大器采用三级放大器级联的结构以满足高达30dB的增益要求。在5V的电源电压下,满足绝对稳定条件,在3GHz-3.5GHz频段内,功率增益为34.5dB,噪声系数为1.5dB,输出1dB功率压缩点为11dBm。     

A cyclotron-wave rectifier for S-band and X-band

A device for converting microwave power into either dc power or low-frequency ac power has been investigated both theoretically and experimentally. Rotational energy is stored in an electron beam by a Cuccia coupler, then converted to longitudinal energy by interaction with a space-dependent dc magnetic field, and finally recovered as electric energy by a depressed collector. A simple kinematic analysis demonstrates that the Cuccia coupler can convert large amounts of microwave power into electron beam rotation. Limits on the electric field strength and asynchronism between signal frequency and cyclotron frequency are established for both classical and relativistic coupler operation. Efficiency analyses of the process of conversion from orbital energy to dc electric energy, both classical and relativistic, indicate that the efficiency exceeds 95 percent for a particular range of operating conditions. As an ac power supply, the device responds to the modulating frequency of the signal. Theory predicts near-negligible harmonic distortion as well as flatness of frequency response from dc to about 1.0 MHz modulating frequency. Four tubes and a prototype (with "artificial" coupler) were tested experimentally. The first three tubes exhibited efficiencies up to 22 percent, being hindered by reflection of electrons into the coupler. Certain design changes were tested on the prototype, where efficiencies from 36 percent to 75 percent were obtained. Incorporating these design changes into the fourth tube yielded measured efficiencies up to 34 percent, or when corrected to disregard unusually large cavity losses, up to 59 percent. Experimental tests of the tube as an ac converter yielded excellent frequency response and about 20 percent second-harmonic distortion. It is concluded that the theoretical foundation of efficiency predictions has thus far been based on too optimistic assumptions.     

制造熔融拉锥分支器件的工作台

介绍了已经被广泛应用的基于熔融拉锥分支（FBT）技术的光纤耦合器的制造设备，并从耦合器制造和新品开发的角度，提出了对工作台的结构和性能的要求。     

S波段TDFA泵浦方式的比较

随着光纤通信技术的发展,对于S波段(1 450～1 520 nm)光放大的需求日渐升高,而Tm+3的能级结构中存在满足S波段光放大的能级跃迁,因此掺铥光纤放大器(TDFA)是S波段最具潜力的激光放大器件,对于光纤通信系统的通信窗口向S波段拓展具有十分重要的意义和价值.由于Tm+3的能级结构非常丰富并且拥有自身的特点,因此TDFA的泵浦波长有着众多的选择,其中一些泵浦方式拥有巨大的商业实用价值.     

宽带服务大众化

2003年9月,宽带世界论坛(The Broadband World Forum)在伦敦举行,论坛深入探讨了电信领域里的亮点.宽带安装示意图和通信量增长示意图描绘了"正处上升势头并朝正确方向发展"的两个领域.这次活动还描画出了未来宽带业务领域的严峻挑战--其中有些是技术上的挑战.     

Method for improving microstrip coupler directivity

This letter describes a method for improving the directivity of the edge-coupled microstrip couplers; the coupler is made up of the suspended microstrip lines. The gap between the dielectric substrate and the ground plane is adjusted to get equal mode velocities under perfect matching conditions. Design data for optimum structure and experimental results are presented and discussed.     

High-order mode coupler for millimetre wavelengths

A new type of injection filter has been developed that can be used for local-oscillator injection in millimetre-wave mixers and other narrowband diplexing applications. The insertion loss for nonresonance frequencies is typically less than 0.25 dB. For the selected resonant modes, the coupler acts as a 3 dB power divider. Insertion losses of 1.5 dB or less can be reached at these frequencies.     

一种新的S频段测控系统校相方法

针对传统的S频段统一载波测控通信系统自动校相方法不能满足日益加重的长管任务,提出了一种新的校相算法,并给出了实现该算法自动化的具体方案。理论分析和实验结果表明,利用该方法进行定向灵敏度标校减小了系统交叉耦和值。自动化的实现节约了人工操作的时间,因此该方法具有速度快、精度高的优点。精度高大大改善了地面测控系统的跟踪性能;速度快缩短了战前标校时间,为任务前地面测控系统快速切换到任务状态赢得了更多的宝贵时间。