超宽带锥形电感特性研究

锥形螺旋电感是一种新型电感,在较宽的频带内有良好的一致性,在毫米波电路和光载无线通信系统（RoF Radio-over-Fiber）中有广泛的应用.本文对锥形螺旋电感感值、螺旋电感长度、直流电阻的计算方法进行了研究,给出了精确计算方法,其中,电感值误差在10.2%以内,直流电阻误差在6.5%以内;对锥形空心螺旋电感微波特性进行研究,提出了一种等效模型,该模型拟合计算结果与实测曲线有较好的一致性,使用该模型给出了螺旋电感宽带特性的详细理论推导,同时利用该模型首次对锥形螺旋电感的宽带特性进行了直观解释;最后,将绕制参数对电感微波性能的影响进行分析,引入单位长度电感量参数α和电感量-频率参数β,可对超宽带锥形电感微波特性进行优化,对某些特性进行快速优化.     

SC切石英晶体谐振器的等效电感一致性分析

SC切石英晶体谐振器是恒温晶振的核心器件,但生产中发现高频SC切石英晶体谐振器的等效电感存在与理论值偏差、一致性差的问题。该文提出了石英晶体谐振器等效电感的计算模型,并系统仿真了生产中可能影响等效电感一致性的因素。仿真结果表明,电极厚度、微调量和微调斑偏移对等效电感的一致性影响不大,而晶片的平行度是影响等效电感一致性的关键,该结论有助于提高SC切石英晶体谐振器的指标和一致性。     

基于闭合磁路的框式薄膜电感的研究

通过磁控溅射工艺制备出三种框式薄膜电感,其中特殊磁芯电感、全磁膜电感为设计制作的具有闭合磁性回路的特殊薄膜电感,而三文治结构电感是目前流行的薄膜电感,这些电感均由下层磁芯层、下层绝缘层(聚偏二氯乙烯,厚度约为40μm)、线圈和线圈中心的磁膜、上层绝缘层和上层磁芯层组成,其差别在于磁芯结构不同。在1~3 MHz频率范围内,比较了三种电感的等效电感、寄生电容和损耗因子。结果表明:与三文治结构电感和全磁膜电感相比,特殊磁芯电感有较高的等效电感量和较小的寄生电容,但损耗较后两者高。     

MLCC的结构设计对电容器等效串联电感的影响

通过分析MLCC内部结构和MLCC等效电路,结合实际制作出不同结构设计的MLCC,并对不同结构产品的等效串联电感(ESL)进行对比,获得了MLCC降低等效串联电感的最佳结构设计方案.     

有源电感的应用

介绍了3种由理想运算放大器组成的有源电感电路原理,利用理想运算放大器的特性推导出有源电感电路的等效阻抗。以50比陷波器为例讨论了有源电感的应用,用Multisim10对这3种有源电感构成的50Hz陷波器进行了仿真。仿真结果,证实了有源电感可以代替滤波器中的实际电感,同时分析了有源电感的损耗同滤波器滤波能力的关系。     

基于LTCC垂直螺旋式电感的研究

采用低温共烧陶瓷技术(Low Temperature Co-fired Ceramic,LTCC)建立多层垂直螺旋式电感模型,系统研究了如何在保证垂直螺旋式电感体积优势的条件下提高电感的Q值;通过集总参数等效,实现垂直螺旋式电感模型感值及Q值的准确提取。在垂直螺旋式电感感值为12 nH的条件下,详细分析了金属线宽、金属线圈层数及金属线圈离地距离对电感Q值的影响。最终将垂直螺旋式电感的Q值由原来的32提高到70以上,实现了多层垂直螺旋式电感Q值的提高。     

用分布电容模型分析和优化差分电感

建立了预测片上等效寄生电容的片上电感分布电容模型.预测和解释了差分电感的自激振荡频率的差异.实测数据显示,与单端驱动模式下的相同对称电感相比,差分驱动模式电感提高最大品质因数127%,具有更大的工作频率范围.设计和验证了低寄生电容的差分电感.     

射频印刷电感替代低值空心电感的探索

本文在多年工作经验的基础上运用现代电子仿真技术,进行印刷电感替代空心电感的尝试,得出射频电路中100n H以下的电感完全可以实现印刷化的结论,并提供了具体的射频仿真软件模拟设计印刷电感的方法实例,掌握这些软件的使用方法,对今后设计印刷电感有至关重要的作用。     

实用的电感测量法

在家电维修中,电感的测量是极为重要的,不仅有利于准确判断电感元件妤坏,而且便于自制和仿制。例如音箱分频器的电感量,开关变压器绕组的电感量以及行输出变压器、偏转线圈的电感量等等。这些元件的电感量直接关系到其性能好坏,维修时通常靠测直流电阻判断其好坏,但这是极不可靠的方法。因为一只电感(例如开关变压器初级线圈)即使圈数完全相同,其电感量误差也相当大。电感量的测量有专用的仪器,如数字式电感电容测量仪。但这些仪器不但成本高,其测试频率也不合要求。测试高压脉冲条件下工作的电感元     

硅基片上螺旋电感宽带物理模型

针对高损耗硅衬底,基于部分元等效电路方法和麦克斯韦电磁场理论,计入了趋肤效应、邻近效应和衬底涡流损耗对螺旋电感串联电感Ls与串联电阻Rs频率特性的制约,并通过n等效电路结构模拟了寄生电容的分布特性,从而建立了一种新的片上螺旋电感物理模型。通过与全波分析方法对比,验证了在20GHz范围内由该模型导出的等效电感Leff,等效电阻Reff和Q值误差均在7%以内。该模型可望用于硅基射频集成电路中螺旋电感进一步的理论探讨和优化设计。     

基于受控源转移和分裂节点的去耦等效法

目前,对互感电路进行去耦等效,一般只解决接在节点上不多于三条含互感支路的去耦等效问题。本文提出的受控源转移概念,利用受控源转移和分裂节点的方法,深入研究了接在节点上多于三条含互感支路的去耦等效问题。本文提出的方法通过对电路图等效变换,获得去耦等效电路。     

Inductance of Nonstraight Conductors Close to Ground Return Plane (Short Papers)

Measurement and calculation of the inductance of a nonstraight conductor close to ground return plane are considered. An equivalent circuit model solution is given, and the results are compared to measurements for a corner-type geometry. Much larger changes in inductance as a function of frequency have been observed for the corner-type geometry than for the equivalent straight-conductor geometry. The circuit model can be used to predict the inductance for other configurations.     

Parameter extraction and electrical characterization of highdensity connector using time domain measurements

Two coupled connector pins can be represented by an equivalent circuit consisting of six parameters, namely, self capacitance/self inductance per pin, mutual capacitance between pins and mutual inductance between pins. A systematic parameter extraction algorithm has been discussed in this paper using time domain reflectometry (TDR) measurements. This method uses a combination of stand-alone, common mode, and differential mode measurements to extract the connector parasitics. The accuracy of the equivalent circuit has been studied in detail using crosstalk measurements     

An experimental study of distributed effects in a microwave bipolar transistor

Conventional microwave transistors are normally considered to operate as a single lumped circuit element. That this is only an approximation has been accommodated in the past by the use of an equivalent circuit including some inductance to correct for the finite size of the contact metallization. The effect of this inductance can drastically change the properties of the transistor when the size of the device becomes a significant part of an electrical wavelength. To study this form of behavior, a transistor with an electrical length on the order of one eighth of a wavelength was constructed. When tested in a suitable circuit, feedback effects involving the metallization inductance caused the transistor to produce four times more stable power gain than would be expected from a conventional transistor having the same area. Amplifiers designed using the new transistor and an equivalent conventional transistor had equal gain-bandwidth products. Other circuit properties of the transistor were observed to be significantly modified, the emitter lead inductance becoming an insensitive parameter while the base lead inductance became very critical. The measured properties of the transistor were found to be in good agreement with theoretical predictions.     

约瑟夫森混合器等效电路参数对三波混频强度的影响研究

约瑟夫森混合器是一种能够生成纠缠量子微波信号的电路。建立了约瑟夫森混合器的等效电路模型,对三波混频哈密顿量进行量子化,研究了约瑟夫森结的临界电流、分路线性电感、谐振器传输线等效电感以及外加穿过环路磁通对三波混频强度的影响。仿真结果表明,约瑟夫森结的临界电流决定了选择的线性电感最大值,而对三波混频强度影响不大;线性电感的大小决定了外加穿过环路磁通的最优值以及三波混频强度的最大值;谐振器传输线等效电感在允许范围内越小越好。研究对于有效选择电路元器件参数,提高纠缠量子微波生成能力有重要价值。     

一种低漏感平面变压器

变压器的漏感是电磁干扰的主要来源之一,这是因为开关管在高速关断时,在变压器的漏感上产生感应电动势,叠加在变压器绕组的关断电压上,形成关断电压尖峰,这些电压尖峰不但造成电磁干扰,还会使开关管的电压应力增大,重者可能击穿开关管,并增大开关损耗,降低开关电源的效率。本文提出一种分布磁路结构的低漏感平面变压器,其原边绕组的匝数降低为一匝,副边绕组的等效匝数降低为小于一匝,因而漏感显著减小,这种分布磁路结构可以用于低压大电流电源的变压器,其有效性通过Maxwell 3D得到验证。     

基于蜗轮蜗杆的3/6 MeV电子直线加速器调谐限位机构设计

作为电子直线加速器的核心装置,微波功率源大多采用高功率磁控管。磁控管的振荡频率由谐振腔的等效电容和等效电感决定。根据改变谐振腔等效电容和等效电感的方式不同,磁控管可以分为机械调谐式和电调谐式两种。本文针对3/6 MeV电子直线加速器中的机械调谐型磁控管设计了一种基于蜗轮蜗杆的外部调谐限位机构。该型调谐限位机构结构紧凑,传动平稳,设置有限位开关和角度传感器,解决了在有限空间内驱动调谐、限位以及监测调谐位置等问题。     

一种采用LC谐振电路的高频差分有源电感

提出了一种采用LC并联谐振电路的新型差分有源电感,实现了宽的工作频带、高的Q值、较大的电感值和可调谐功能。采用无源电感和MOS晶体管可变电容构成LC谐振电路,减小了等效串联电阻和等效并联电容,在增大电感值、Q值的同时,扩大了工作频带。仿真结果表明,在2~7.6 GHz频率范围内,该新型差分有源电感的电感值大于26 nH,Q值大于138;在7.6 GHz高频下,电感值达130 nH,Q值达418,实现了宽工作频带范围内的高Q值和高电感值。与传统差分有源电感和带LC谐振电路的单端有源电感相比,该新型差分有源电感的性能较好。     

Speeding Up PEEC Partial Inductance Computations Using a QR-Based Algorithm

The partial element equivalent circuit (PEEC) approach has been used in different forms for the computation of equivalent circuit elements for quasi-static and full-wave electromagnetic models. In this paper, we focus on the topic of large scale inductance computations. For many problems as part of PEEC modeling, partial inductances need to be computed to model interactions between a large numbers of objects. These computations can be very time and memory consuming. To date, several techniques have been devised to reduce the memory and time required to compute the partial inductance entities, as well as the time required to use them in a circuit analysis compute step. Some of the existing methods use hierarchical compression while some others are based on issues like properties of the inverse of the partial inductance matrix. However, because of inherent limitations, most of these methods are less suitable for PEEC applications. In this paper, we present an approach which is based on the compression of the partial inductance matrix utilizing the QR decomposition of the far coefficients submatrices. The QR-decomposed form is represented as a compressed SPICE-compatible circuit. This yields an efficient and mathematically consistent approach for reducing the storage and time requirements