宽带RC恒相差网络的性能分析

本文深入地分析了由两个ＲＣ全通网络构成的恒相差网络的相差频率特性，推出了简明的相差频率特性公式，提供了通用的相差频率特性曲线，由于把频率特性由原来取决于三个参数归结为一个可选的参数，从而为评估和设计这种网络找到了一条简捷的途径。     

RDCLI主回路设计与拓扑优化

研究了ＲＤＣＬＩ交换传动系统主回路设计，提出一种使ＬＣ损耗最小的参数设计方法，给出了有源钳位网络参数计算公式及实验系统主回路。对几种改进的拓扑结构在交流传动方面的适应性及其优缺点做了分析比较。     

电压型逆变器式有源滤波器分析

分析电容器Ｃ的初始充电过程电压型逆变器工有源滤波器的稳定工作状态,提出四个用于判定该种有源滤波器工作和有助于该有源滤波器设计的参数。对充电过程的分析结果表明,此种有源滤波器无需附加设备就能自动完成充电过程。除此之外,作为稳态分析的结果,给出确定电压型逆变器式有源滤波器元件参数的原则。     

镜像元件及其应用

阐述了镜像元件的特性,包括零器-镜像元件连接的等效性;提出了镜像元件进而病态元件的级联特性,同时引入镜像元件完善了CCII族;对现代电网络分析中考虑镜像元件的方法进行了总结.镜像元件能够灵活地表示有源器件和等价电路,常在复杂的电路设计与分析中提供灵活和简洁的方法,其作为基础的病态元件应用越来越广泛.     

微波网络的计算机辅助设计

一引言微波电路,往往既包含有集中参数元件,又包含分布参数元件,其频率特性比较复杂。一般很难用经典方法,按给定要求去综合电路。另外,在微波电路的制造过程中,常采用微带电路,在大多数情况下,电路没有调谐余地,修改电路比较困难,因此在制造以前,必须非常精确地设计电路参数,否则所得出的特性会大大偏离设计要求。随着表征器件的模型和自动测试技术的发展,目前已能用S参数来表征微波波段的有源器件,这就为微波网络的计算机辅助设计创造了条件。     

国外片式机电元件的技术发展

随着电子整机产品向簿、轻、短、小、数字化、高可靠以及智能化方向发展，电子元件正向微小型化、片状化、低噪音、高性能和复合化方向发展，电子组装技术也发展采用表面安装技术ＳＭＴ。片式元件分片式无源元件、片式有源器件和片式机电元件。该文着重介绍国外近期发展的片式机电元件中的片式开关、片式连接器（ＳＭＣ）、片式继电器（ＳＭＲ）和簿型微电机等典型结构和技术发展动向及其应用情况。     

PTC元件参数特性微机自动测试装置

论述了ＰＴＣ元件参数特性微机自动测试装置的结构设计，Ｒ－Ｔ、Ｖ－Ａ、Ｉ－Ｔ测量信处理，炉温模糊控制，上下位通讯，软件设计等项技术的实现方法。     

LCR元件参量传感器检测的新方法

在论述ＬＣＲ元件参数精密自动测量的三种方法缺点基础上，提出现今采用阻抗分量单独测量方法的必要性，随之介绍了圆心法确定特征圆的基本理论、特征网络和辅助支路的建立方法、测差指示器结构形式，最后给出了圆心法阻抗分量单独测量仪的原理框图。     

PTC元件参数特性微机自动测试装置

论述了ＰＴＣ元件参数特性微机自动测试装置的结构设计，Ｒ－Ｔ、Ｖ—Ａ、Ｉ－３”测量及信号处理，炉温模糊控制，上下位通讯，软件设计等项技术的实现方法。     

新型电子触发器电路介绍

新型电子触发器电路介绍王大魁，王令义一、简介气体放电灯用电子触发器（ＥＬＥＣＴＲＩＣＩＧＮＩＴＯＲ），其主要元件一般都使用质量上乘的可控硅（ＴＲＩＡＣ）器件，再配以外围元件而组成。一个性能较好的触发器产品，元件数量在１１～１４个之间。图１、图２所示为...     

Selection of power semiconductor devices for parallel connection

The method of selecting power semiconductor devices for group parallel connection on the basis of models developed on the basis of the measured electrical and thermal parameters and characteristics of certain devices are considered. Experimental data are obtained using the ADIP-6 test equipment. The electrical part of the model is constructed on the basis of the electrical parameters of the volt–ampere characteristic in a high-conductivity condition, and the thermal part is developed on the basis of the electrothermalanalogy method. The parameters of the thermal model are determined on the basis of the measured value of the thermal junction-to-case resistance in the steady-state thermal mode. The electrical and thermal parts of the model are connected through the temperature dependences of the volt–ampere characteristic parameters. A sample of ten power diodes is considered as an example, parallel connections consisting of two diodes are constructed of them, and the electrical and thermal processes are analyzed in this group using the simulation method for all possible combination of the diodes. The potentially reliable and unreliable diode combinations were specified on the basis of the simulation results. The temperature of the semiconductor structure is used as a criterion for determining reliability. A connection in which the temperature of the semiconductor structures of the devices included in the connection did not exceed the admissible limit value was considered as potentially reliable. Two connections, referred to as “potentially reliable” and “potentially unreliable” connections, are considered as an example.     

Recursive calculation of ladder circuit frequency functions

It is shown how the transfer function as well as the input impedance and admittance of any linear time-invariant ladder circuit can be determined in closed form as frequency functions dependent upon the network element parameters. All elements of the ladder circuit must be explicitly specified by their frequency characteristics. The results are achieved with the aid of recursive algorithms. The outcome is demonstrated by means of an example.     

Linear frequency networks with applications to ‘frequency set-on oscillators’ and ‘self-adaptive bandpass filters’

A ‘linear frequency network’ is a network system which consists of an arbitrary connection of devices, each of which performs a linear transformation on the instantaneous frequency of a signal. Thus a transfer function may be defined relating the output to input instantaneous frequency. Particular networks are investigated. the first is a basic section, producing a ‘self-adaptive bandpass filter’ which is then applied to a ‘frequency set-on oscillator’. Such an oscillator is a multimode oscillator where any mode will be stable when excited by a sample of an RF pulse adjacent to the mode. Cascading these basic sections results in an nth-degree ‘self-adaptive bandpass filter’ producing a bandpass characteristic which tracks a carrier frequency. Experimental devices in the 400-600 MHz band are shown to have excellent agreement with theory, and applications to digital RF memories, ESM receivers and frequency memory loops are discussed.     

High-voltage power sources for powerful SHF devices with pulse-periodic output voltage

Problems in the development of high-voltage power sources (HVPSs), magnetrons and gyrotrons, providing powerful SHF devices of two types with a continuous generating mode of SHF and periodic-pulse radiation have been considered in this paper. High-voltage power sources (HVPS) are made on the basis of a transistor–capacitor direct-voltage converter. It ensures parametric stability and safety of the HVPS–powerful SHF device system in standard operating conditions and the emergency-operation mode due to HVPS’s negative external characteristic of this type. Mathematical models of an HVPS–powerful SHF device loop describing processes at the various output-voltage pulse-forming stages of HVPS’ have been proposed and checked. An HVPS–powerful SHF device system using the control-current injection method has been analyzed. A feedforward compensator the parameters of which are determined by confinement conditions in the given ranges of output regulation limits and dynamic parameters of forming pulses has been constructed using the asymptotic-expansion method of log-magnitude curves. Taking into account the results that have been obtained, a number of HVPS devices have been produced for technological and research SHF complexes. Basic technical specifications of two developed HVPS devices have been provided as an example in this paper. The first HVPS, which has a medium-voltage power of 60 kW (25 kV/2.4 A), enables generation by an SHF radiation gyrotron of up to 20 kW of capacity in both continuous- and periodic- pulse modes with a maximum frequency of 10 Hz. The second HVPS, which has a medium-voltage power of 20 kW (5 kV/4 A), is intended for supplying power to an M-168 magnetron in the periodic-pulse generation mode of SHF radiation with a maximum frequency of 500 Hz.     

Critical element analysis for the transfer,gain and phase functions in linear active filters

In linear active filters, the element criticalness, the most and the least critical elements, and also optimum tolerances have been defined for transfer, gain and phase functions. Simple and systematic procedures for computing their values, thus determining the ordered hierarchy of critical elements, are provided. Moreover, as an example, the element criticalness, the most and the least critical elements, and the optimum tolerances have been evaluated for Gopal's network realizing the third-order Butterworth characteristic and using equal-valued capacitors and resistors.     

粒子群算法在励磁参数实测辨识中的应用

针对采用频域分析和最小二乘拟合对复杂模型进行辨识时比较困难的缺点,文章提出了一种采用粒子群算法进行励磁系统参数拟合辨识的方法,该方法直接采用幅频特性和相频特性来定义适应度函数,实现过程简单.实际算例表明,提出的方法对简单模型和复杂模型都可以得到较好的辨识效果.     

电动挖掘机交流变频系统电能反馈制动装置

电动挖掘机交流变频调速系统一般采用简单的能耗制动,存在浪费电能、电阻发热严重,快速制动性能差等缺点。本文结合电动挖掘机的工作状况,拟研制开发交流变频调速系统电能反馈装置,反馈装置作为有源逆变单元,并联到变频器的直流侧,将挖掘机制动过程中产生的再生能量反馈到交流电网中。该装置既可以为矿山企业节约电能消耗,降低生产成本;又能提高电动挖掘机的工作性能,改善调速精度。这对提高矿山企业的经济效益和社会效益是非常重要的。     

Computer-aided design of broad band reflection type amplifiers

Microwave negative resistance reflection type amplifiers using stable transferred electron devices (TED's) are optimized by numerical optimization techniques programmed for an interactive graphic datascreen. The small signal impedance of packaged TED's is measured on an automatic network analyzer. At the same time the impedance of unpackaged devices are obtained by on-line correction for the package parasitics. The microwave circuit chosen is a multiple slug coaxial cavity, that is modelled by sections of lossy transmission lines including step susceptances. The measured small signal impedance of the packaged TED's and the cavity model are used in a direct optimization procedure, in which the calculated minimum gain in the prescribed frequency range is progressively maximized by adjusting the lengths, characteristic impedances and positions of the slugs. The computed results are displayed on a datascreen, which allows for interactive programming. Comparisons of predicted amplifier performance for packaged and unpackaged devices form a basis for evaluating the possible degrading effect of package parasitics. The predictions of the computer-aided design are in good agreement with experimental results. The design procedure imposes no restraint on the frequency variation of the active device impedance and is therefore useful for any stable broad-banded negative resistance device.     

SiC MOSFET功率器件特性参数的提取与拟合

为了对碳化硅(SiC) MOSFET功率器件的特性参数进行全面的研究,提出了一种碳化硅(SiC) MOSFET变温度参数模型,该模型考虑了功率器件中封装引脚寄生电感、内部寄生电容、体二极管等特性参数,并根据器件的开关过程中的不同阶段,将功率器件中的导电沟道等效为不同电路模型。为获取该模型中的涉及的特性参数,搭建了基于Agilent B1505A功率半导体分析仪和矢量网络分析仪(VNA)的测试平台对SiC MOSFET功率器件的静态特性参数进行了全面测量,然后使用基于贝叶斯正则化LM算法的改进BP人工神经网络对所测的数据进行非线性拟合。结果表明,相较于传统拟合方法,该方法具有更高的精确度与泛化能力,为SiC MOSFET功率器件建模与参数分析提供了重要依据。