一种新型微带曲折线慢波结构的设计

设计了一种新型微带曲折线慢波结构,该结构采用双介质杆支撑式的V型平面曲折线慢波电路。利用电磁场仿真软件HFSS对这种新型结构和传统微带曲折线慢波结构进行了分析比较,研究结果表明,新型微带曲折线慢波结构在不改变色散强弱的情况下,工作频段向高频端拓展且耦合阻抗有了很大提高,可以更好地工作在短毫米波段。并仿真分析了结构参数对高频特性的影响,所获得的仿真结果为器件的粒子模拟及计算慢波结构的工作效率奠定了基础。     

Microfabrication and Characterization of a Selectively Metallized W-Band Meander-Line TWT Circuit

Vacuum electronic devices offer significant potential for increased power and performance at millimeter-wave frequencies. However, new approaches are required to reliably manufacture the miniature electromagnetic circuits used at these high frequencies. In this paper, we describe the design, fabrication, and testing of an innovative meander-line slow-wave structure for a W-band traveling-wave tube (TWT). The unique challenge of metallizing only the top of a high-aspect-ratio serpentine dielectric ridge using conventionally planar microfabrication techniques is overcome using a novel selective masking and metallization process. The procedure is demonstrated by fabricating a W-band meander-line circuit for a 10-W continuous-wave TWT. Cold-test S -parameter measurements are presented.     

超宽带折线圆极化器的优化设计

本文利用折线栅的等效电纳对多层折线圆极化器进行等效，根据其等效网络，采用罚函数当和变尺度法对四层板折线圆极化器进行优化设计，得出了不同频率范围内极化器的结构尺寸，并计算了相应的轴比，计算机模拟结果表明，在２－１８ＧＨｚ，频率范围内，所７设计的圆极化器轴比低于１ｄＢ，具有较好的实用价值。     

新型曲折线全向型陶瓷天线及阵列的设计与仿真测试

基于移动通信终端设备对天线体积的要求,设计了一种新型的曲折线结构全向型陶瓷天线,其谐振频率为1.85 GHz,521-1 5.5 dB,最大尺寸为0.06λ0.对陶瓷天线二元阵列进行了仿真与测试,发现虽然在陶瓷中可以很好地控制单元天线的相位,但是在空气中由于干涉效应不明显,并不能很好地控制方向图.故设计各单元天线独立馈电的阵列时,单元间距应该达到可以与λ0相比拟的程度.     

微带型曲折线慢波结构冷测特性的计算机仿真

在研究了微带型曲折线慢波结构色散特性、耦合阻抗等特性参数的分析方法基础上,利用电磁场仿真软件MAFIA和Microwave Studio对其进行模拟计算。对影响慢波电路特性的结构参数如微带宽度和微带厚度对其冷测特性的影响进行了仿真和分析,同时对介质杆支撑的曲折线慢波电路进行了分析。结果表明,微带宽度对其特性影响较为显著而微带厚度的改变影响不大,介质杆代替介质板使慢波电路的特性参数产生了较大的变化。     

A Design Method for Meander-Line Networks Using Equivalent Circuit Transformations

Many types of coupled structures are used to design microwave filters and equalizers. One such structure is the array of coupled parallel commensurate conductors called a meander line. There are several analysis techniques that may be used to find the equivalent circuit of a meander line. However, these do not provide exact design equations. In this paper, meander-line networks are analyzed and synthesized using the graph-transformation technique. The equivalent circuits of one- and two-port meander-line networks will be developed by using the transformation method, and it will be shown that meander-line networks can be easily designed by using the electronic computer.     

变压器和电感器

可承载40A的自屏蔽SMT电感器 HM73系列钼铁镍合金粉末自屏蔽SMT电感器从0.1～8.2μH有16种额定值,最高可承受40A和400μJ/cm~3。它们是用导体密度比圆形导线高20％的超薄矩形导线制造的,它们还具有0.08～15.2mΩ的DCR。     

变形金刚

高中生山姆终于拥有了自己平生第一辆汽车,这车外观虽然破旧点,但是却仿佛通人性一般保卫着他和女友。有一天,这辆黄色的二手车突然变形成为了一个高大的机器人。原来,来自外星球的可变形机器人已经追踪着     

Transmission-Line Transformers

The radio-frequency transformers described in this paper consist of matched transmission lines of equal length and characteristic impedance. The lines are connected according to rules given in the text. These transformers exhibit a very broad frequency response which can be readily estimated; two methods of analysis are presented. The computations agree well with the test results.     

小型化和微型化电子变压器

简要介绍了小型和微型电子变压器生产中采用的材料和技术，以及封装式和无线引式电子变压器。     

Stepped-Impedance Transformers and Filter Prototypes

Quarter-wave transformers are widely used to obtain an impedance match within a specified tolerance between two lines of different characteristic impedances over a specified frequency band. This paper gives design formulas and extensive tables of designs, most of which were especially derived so that an integrated account could be presented for the first time. Numerous examples are given. Only homogeneous, synchronous transformers and filters are included in this paper, but a short bibliography on related topics is appended. The theory is also applied to band-pass filters, by showing how to convert quarter-wave transformers into half-wave filter prototypes. The theoretical and numerical results presented are applicable to the design of impedance transformers, direct-coupled cavity filters, short-line low-pass filters, optical antireflection coatings and interference filters, acoustical transformers, branch-guide directional couplers, TEM-mode coupled-transmission-line directional couplers, and other circuits. These applications have been or will be dealt with in separate papers; this paper gives the basic theory and some of the numerical data required for these applications.     

Optimum Quarter-Wave Transformers

The design of uniformly dispersive quarter-wave transformers is a well explored subject. Common examples are rectangular waveguide E-plane transformers, in which the a dimension is kept constant. In this paper, it is shown that the performance of conventional quarter-wave transformers of a single section can always be improved by making the middle section less dispersive than the input and output waveguides, and a formula for the optimum a dimension is given. The theory was verified experimentally. In this instance, the improved transformer measured 50 per cent more bandwidth than did the conventional one, and was 25 per cent shorter besides.     

铁氧体平面变压器

简述铁氧体磁芯平面变压器的制作方法及其应用。     

Short-Step-Stub Chebyshev Transformers Impedance

A transfer function for short-step impedance transforming filters consisting of short cascaded TEM transmission-line sections and at least one commensurate length open-circuit stub is described. Element values are given for a particular family of octave-bandwidth short-step transformers that are much more compact than existing short-step transformers.     

Current Transformers for Inverters

A design method for low frequency current transformers for inverter and motor drive applications is presented. Toroidal and E-I cores based design alternatives are studied and compared.     

Short-Step Chebyshev Impedance Transformers

Impedance transforming networks are described which consist of short lengths of relatively high impedance transmission line alternating with short lengths of relatively low impedance line. The sections of transmission line are all exactly the same length (except for corrections for fringing capacitances), and the lengths of the line sections are typically short compared to a quarter wavelength throughout the operating band of the transformer. Tables of designs are presented which give exactly Chebyshev transmission characteristics between resistive terminations having ratios ranging from 1.5 to 10, and for fractional bandwidths ranging from 0.10 to 1.20. These impedance-transforming networks should have application where very compact transmission-line or dielectric-layer impedance transformers are desired.     

Analysis and Design Procedure of Transmission-Line Transformers

Transmission-line transformers are devices used to match RF and microwave devices, to make the conversion balanced-unbalanced, or both things simultaneously. Transmission-line transformers are mandatory at frequencies where traditional magnetic coupling transformers do not operate properly. In this paper, a procedure to design transmission-line transformers with different configurations is presented. The procedure is based on the theoretical analysis of the device and has been validated via experimental study.     

Exponential Transmission Lines as Resonators and Transformers

An attempt has been made to analyze the theory of an exponential transmission line from its complex reflection coefficient's standpoint and to indicate how the characteristics of an exponential line can be completely represented for any frequency with the help of the Smith Chart. It is shown that the optimum design parameters of an exponential transmission line which maybe used as a transformer, with a frequency-sensitive load at one end, can be determined with the help of the Smith Chart and some derived equations. This paper also includes a study of the coaxial type exponential line which can be used as a series or parallel resonator. Theoretical expressions for the attenuation constant, stored energy, and Q for such types of resonator have been derived. Also indicated in this paper is the possibility of replacing the uniform-line coaxial-type resonators in many microwave and uhf wave filters by the exponential-line resonators, particularly when a large power-handling cpacity is warranted.     

汽车人的宿命《变形金刚2》大战再起

可能在你拿到《数字家庭》6月刊后的第十天,《变形金刚2》将再次用超炫的电影科技让你的视觉神经享受一顿大餐。你也许就是当年那一群看着变形金刚长大的孩子,也曾经梦想着拥有一个变形金刚玩具：