中周模型在Multisim中的实现

为了解决用Multisim仿真高频单谐调谐振放大模块无中周模型的问题,通过对高频小信号放大模块的理论分析,总结出用LC电路模型替代中周电路模型的方法,做了高频单谐调谐振放大模块的仿真实验,获得了正确的仿真实验结果,该方法对用Multisim仿真高频谐调谐振放大模块具有借鉴意义。     

应用IGBT的小型化医用二氧化碳激光器电源

应用谐振型功率转换电路，采用谐振型电流过零关断方式工作利用高频变压器，制作出一种小体积、重量轻的，可精密调节的高稳定度电源。     

250KHz谐振自激直流变换器

谐振自激直流变换器,利用功率场效应管的栅极输入电容与微型线性电感(几微亨至几十微享)之间的并联谐振,产生数百千赫的自激振荡,完成高频直流-直流变换.由于不需要传统的可饱和变压器作控制元件,这种变换器电路简单、效率较高,而且更容易实现高频化.本文分析了高频谐振自激变换器的工作原理,并给出了一个250KHz谐振自激变换器的实例.     

谐振区目标散射特性与曲面绕射机理的研究

针对目标在谐振区的散射模型，提出了将高频方法应用于谐振区的两种改进办法，用以解决高频方法在谐振区精确度有所下降的问题.在谐振区，随着频率和目标电尺寸的降低，对于表达式中的高频级数解，需要更多的求和项才能使级数得以收敛，除此之外还考察了高阶爬行波对散射场的影响.在此基础上，为了分析谐振区的散射特性与散射机理，将混合几何光学-物理光学算法与一致性几何绕射理论相结合，同时推导了爬行波随爬行距离等参数衰减的表达式，并且通过计算金属球和二维圆柱的散射场，总结出目标在谐振区的散射特性.     

高频功率放大器最佳导通角的理论定义与控制

介绍了高频电子线路中谐振功率放大器的最佳导通角的定义，并通过严格的理论分析，给出了其求解方程，然后利用方程近似解法，通过计算机编程求出了最佳导通角的具体解，并分析了他在具体设计中的应用。     

高频高压电源LCC谐振电路的研究与设计

本文研究并设计了一种应用于静电除尘高频高压电源的LCC谐振电路。首先分析了LCC谐振电路拓扑结构和谐振电流断续模式下的工作原理,然后在此基础之上结合高频高压变压器的特点给出了LCC谐振参数的设计方法,最后通过仿真和实验验证了LCC参数设计的有效性。     

高频整流电路的改进研究和仿真分析

分析了高频整流电路输入电流的谐波特性,并在高频整流电路的基础上进行了改进,分别加入了并联谐振电路和低通滤波器。利用Multisim构建了仿真模型,给出了仿真模型中电路的参数,得到了仿真结果。仿真结果表明,高频整流电路的改进设计方法可有效地抑制电源模块输入电流的谐波     

一种应用于18GHz功放模块的陶瓷外壳设计

提出了一种用于Ku波段功放模块的陶瓷墙型外壳,在传统射频传输端口结构的基础上,利用高频仿真软件HFSS分析高频产生谐振的原因,并通过改进射频传输端口的结构,消除了谐振。用本征模求解器仿真腔体的谐振频率,确保其基模频率高于外壳工作频率。测试结果表明,在DC-18GHz的频段内,外壳射频传输端口具有较小的插入损耗与较大的回波损耗,射频传输端口之间具有较高的隔离度。     

本征模在电源完整性分析中的应用

针对日益复杂的多层基板电源完整性问题,提出了一种基于本征模分析所需频段内PDN(Power Delivery Network)阻抗大于目标阻抗的仿真设计方法。基于13层的AlN基板,利用AnsysSiwave电磁仿真软件提取电源分配网络的Z阻抗曲线,观察响应上是否有谐振点。针对谐振点,利用本征模观察谐振频点的谐振分布,确认最大谐振位置。通过在最大谐振位置上加载去耦电容的方式将谐振频点移至高频,以此使电源Z阻抗满足目标阻抗需求。     

高频谐振功率放大器的仿真教学探究

高频谐振功率放大器是"高频电子线路"课程中重要且基础的章节,但其中的信号分析方法十分抽象.本文提出了对余弦脉冲电流信号进行频谱展开的仿真分析,以及对高频谐振功率放大电路中节点电压信号仿真的教学方法,此方法有效地丰富了课程的教学内容,降低了学生的学习难度.     

Linear multiloop control of quasi-resonant converters

The aim of this paper is to study the stability of linear multiloop control of quasiresonant converters (QRC). It is shown that a P-current feedback, plus an I-voltage feedback suffices to stabilize a QRC. A systematic procedure of control synthesis is presented and stability conditions for the control parameters are derived from nonlinear systems theory. Performance of the proposed controller is verified through an experimental application in a boost type QRC.     

Buck quasi-resonant converter operating at constant frequency:analysis, design, and experimentation

A buck pulsewidth modulated zero-current switching quasi-resonant converter (buck PWM ZCS QRC) operating at constant frequency is discussed. Operating principle and design-oriented analysis are presented with normalized design curves, design procedure, design example, simulations, and experimental results. The new topology, which can be considered as a particular one, is compared with the well-established buck frequency-modulated zero-current switching quasi-resonant converter (buck FM ZCS QRC) proposed by Fred C. Lee (1988)     

A new soft recovery PWM quasi-resonant converter with a foldingsnubber network

A new soft recovery (SR) quasi-resonant converter (QRC) having a multiple-order folding snubber network (MFSN) is introduced. It is obtained by combining a normal QRC with a folding snubber network of which the surrounding components are composed of passive devices only (diodes and capacitors). The reverse recovery loss of the main rectifier diode is eliminated by this method utilizing multiple resonance with a multiple-order folding snubber network. By realizing soft switching conditions, the proposed converter has pulsewidth modulation capability with high efficiency and is suitable for high-voltage and high-power DC to DC converter applications     

A simple large-signal nonlinear modeling approach for fastsimulation of zero-current-switch quasi-resonant converters

A nonlinear modeling approach for zero-current-switch (ZCS) quasi-resonant converters (QRC) is proposed which can be derived easily using simple analytical techniques. The converter model obtained is readily absorbed by MATLAB for analysis and design of both the open- and closed-loop configurations in fast speed. Simulations have shown its accuracy, even for large-signal transient responses. Applications of this modeling approach to the three basic topologies of buck, boost, and buck-boost converters are given as illustrative examples. The condition for zero-current switching is identified from the model. The feasibility of applying this proposed modeling approach to the extended period QRC topologies is to be discussed. Simulation results for the three basic topologies are given to show the merits of the proposed modeling approach     

Zero-voltage-switched quasi-resonant buck and flybackconverters-experimental results at 10 MHz

Experimental results are presented for buck and flyback zero-voltage-switched (ZVS) quasi-resonant converters (QRCs) operating above 5 MHz. A design procedure for a buck ZVS QRC is proposed that minimizes voltage stress to the power MOSFET transistor while maintaining zero voltage switching for specified ranges of input voltage and load resistance. A quasi-resonant gate drive scheme is also proposed and implemented in a buck converter. The drive is simple and provides high switching speed. Power dissipation in the gate drive is substantially reduced due to the quasi-resonant operation. The ZVS QRC technique described is suitable for very-high-frequency operation due to its ability to reduce dynamic turn-on losses, Miller effect, dv/dt, and di//dt and can be applied in distributed onboard power supplies     

A unified averaging technique for the modeling of quasi-resonantconverters

A unified averaging technique, here called the generalized state-space averaging (GSSA) technique, for the analysis of a class of periodically switched networks is proposed in the present paper. The basic assumption of GSSA is that the switching frequency must be much higher than the highest natural frequency of the networks, while the input variables can be bounded fast time-varying functions. It is shown in this paper that the GSSA approach generalizes the idea of the averaging technique to overcome the limitations of the conventional state-space averaging method, which prevents us from applying it to quasi-resonant converters (QRCs). The application of GSSA to the analysis of QRCs has been illustrated via examples of the zero-current switching QRC buck converter and zero-voltage switching QRC boost converter. Its accuracy has been verified by numerical simulation and experimental results     

Integrated ZCS quasi-resonant single-stage high power factorconverter

A new single phase zero-current-switched (ZCS) single stage quasi-resonant converter (QRC) for power factor correction (PFC) is proposed. The converter provides a good power factor, has tight output regulation, and low line current harmonic distortion. The proposed converter is suitable for low power level power supplies with high efficiency and tightly regulated output voltage     

A unified approach to modeling, synthesizing, and analyzingquasi-resonant converters

This paper presents a general method of modeling, synthesizing, and analyzing quasi-resonant converters (QRCs), including actively clamped QRCs. First, the concept of the pulse-width modulation (PWM) switch model is generalized to encompass all PWM (nonisolated) converters. Then, by adding inductor-capacitor (LC) elements and auxiliary switches into the PWM switch, QRC families are synthesized. DC and small signal analyses can be carried out based on these switch models. Furthermore, the duality relationship between zero-voltage-switching (ZVS) and zero-current-switching (ZCS) QRCs is established systematically and rigorously     

Integrated ZCS quasi-resonant power factor correction converterbased on flyback topology

An integrated zero current switching (ZCS) quasiresonant converter (QRC) for the power factor correction with a single switch is presented in this paper. The power factor correction can be achieved by the discontinuous conduction mode (DCM) operation of an input current. The proposed converter offers good power factor, low level line current harmonics, and tight output regulation. The design equations are suggested and a prototype converter has been designed based on these equations and experimentally investigated. The input current waveform of the prototype shows less than 15% of total harmonic distortion. Also, the efficiency and power factor of about 84% and 0.977, respectively, can be obtained under the rated condition     

Single-cycle resonant converters: a new group of quasi-resonantconverters suitable for high-performance DC/DC and AC/AC conversionapplications

A novel resonant switch and a family of zero-current and zero-voltage mixed-mode switching quasi-resonant converters (QRCs) called single-cycle resonant converters (SCRCs) are proposed to improve the performance of the conventional QRCs. The SCRCs, which include two active switches operated with zero-current switching (ZCS) and zero-voltage switching (ZVS), respectively, show very simple operation and ease of control and analysis, and they overcome the limited load range characteristics of the conventional ZCS QRCs. The SCRCs can be applied even for a high-frequency AC chopper by replacing unidirectional switches with bidirectional ones. Steady-state operation and characteristics of the buck-type SCRCs are analyzed and compared with those of the buck-type full-wave QRC (FW-QRC). Experimental results at a a 200 kHz, 1 kW level are shown to verify the operational principle and characteristics