M级交错N重开关并联移相驱动的单相功率因数校正器

对于单相交流电源供电的大功率家用变频空调、通讯电源等用电设备,需要采用大功率单相功率因数校正器,如多级交错APFC或在单级APFC中采取多个功率器件并联。本文提出和理论分析了一种M级交错、N重开关并联且所有功率器件移相驱动的APFc（MXNAPFC）,分析了其电路结构和工作原理．包括电压变比、纹波电流、驱动方法和控制方...     

高功率微波效应的多物理场建模方法研究

为了实现对微波器件高功率微波效应的分析,主要从不同尺度半导体器件和波导器件出发,基于具有谱精度的谱元时域法,开展从微米尺度到纳米尺度半导体器件电热耦合一体化分析的方法以及高功率微波气体放电效应及抑制机理的研究.得到了半导体器件在电磁信号作用下发生的电热参数分布变化规律和微波器件在高功率微波下发生的气体放电及其抑制机理,根据以上相关效应机理,可为复杂电磁环境中的器件设计提供理论指导.     

Harmonic Power Combining Of Microwave Solid-State Active Devices

A method for combining the power in a selected harmonic of the fundamental frequency for a symmetrical array of oscillating solid-state devices is described and demonstrated. These combiners convert fundamental power to harmonic power with filtering accomplished by symmetry. This technique appears useful for improving the performance of microwave and millimeter-wave power sources by effectively enhancing the frequency-power limitations of existing solid-state devices. An example of the method is provided by a simple three-phase frequency-tripling varactor-tuned transistor oscillator.     

Power cycling analysis method for high-voltage SiC diodes

This work describes a novel analysis method for the power cycling test, developed for high-voltage and temperature silicon carbide diodes. The silicon carbide devices working at temperatures beyond 170 °C, the maximum temperature rating for silicon devices, need specific reliability tests adapted to high temperature operation of this new generation of power devices. The specificity of the further presented method consist in the use of 10 ms sinusoidal power current pulses that are able to evidence the temperature developed inside the diode during the power pulse, the temperature characteristic delay versus the applied current and the temperature calibration method. Moreover, this overall method is able to evidence the transformations occurred in the bonding contact and the dye attach.     

耗散功率与环境温度对功率VDMOS热阻的影响分析

运用电学测试法,以两款不同封装类型功率VDMOS为实验对象,考察了耗散功率和环境温度对器件稳态热阻值的影响。结果表明：器件热阻值不是一个恒定不变的常量,由于电流拥挤效应,材料导热系数等条件的改变,它会随耗散功率及环境温度的增大而增大。该研究加深了对功率器件热阻理论的认识,为功率VDMOS的热特性评估提供了可靠的依据。     

评价功率VDMOS器件SEB效应的畸变NPN模型

构建了一个半径为0.05μm的圆柱体,用于模拟单粒子辐射功率VDMOS器件的粒子径迹,且圆柱体内新生电子和新生空穴的数目沿圆柱体的半径方向呈高斯分布。考虑到功率VDMOS器件的SEB效应与寄生NPN具有直接关系,提出了一种畸变NPN模型,并通过合理假设,推导出功率VDMOS器件在单粒子辐射下安全漏源偏置电压的解析式。结果表明,使用解析式计算得到的SEB阈值与TCAD仿真结果吻合较好。该模型可被广泛用于功率VDMOS器件SEB效应的分析和评价,为抗辐射功率VDMOS器件的选型及评价提供了一种简单和廉价的方法。     

An advanced PWM-switch model including semiconductor device nonlinearities

Contrary to the classical ideal averaged models, the introduced averaged model includes the nonlinear effects of the power semiconductor devices. The proposed nonideal pulse width modulated (PWM)-switch model is a useful method for modeling pulse width modulated converters operating in the continuous conduction mode. The main advantages of the proposed averaged model are that it takes into account the nonlinear effects of power devices and make it possible to estimate the dissipated power in the different circuit devices. The proposed model can be applied to bi-directional converters and allows the electrothermal simulations of the power electronic system. A simple technique to evaluate the different static and dynamic parameters of the devices, from manufacturers data sheets or experimentally, is presented.     

基于IGBT并联技术的PEBB设计

受电力电子器件生产制造工艺的限制,为了提高电力电子装置的功率等级,一般采用电力电子器件直接串并联或是变流单元多重化串并联的方法。文章在总结绝缘栅双极晶体管并联技术的基础上,设计了一个容量为250kVA的功率半导体组件。试验结果表明,该PEBB设计符合各项指标,具有很强的实用性和可操作性。     

CMOS-compatible silicon devices on thin SiO2 membranes

A novel method of fabricating low power silicon-based devices on thermally insulating membranes for use in sensing applications is presented. The devices can be operated at temperatures of ~250°C with power consumption not exceeding 25mW     

Measurement of white and 1/f noise within burst noise

A measurement method is described which enables the separate measurement of the power spectra of the normal noise (white and l/f) superimposed on burst noise. With this method the power spectra of normal noise can be determined for each burst noise level. It is found that the clean burst noise and the superimposed normal noise are generated by statistically independent processes. The fact that burst noise devices have a higher 1/f noise power content than devices without burst noise indicates that there exists a common condition for the generation of burst noise and 1/f noise.     

Heat propagation in H-bridge smart power chips under switching conditions

A method for a time-dependent solution of the heat conduction equation for semiconductor power devices will be presented. The mathematical approach to the solution is taken with the help of the eigenfunctions and eigenvalues theory, a suitable approach for these types of problems. Examples for the application of this solution for smart power devices under switching conditions will be presented.     

A broadband high-efficiency Doherty power amplifier using symmetrical devices

This paper proposes a method for broadband and high-efficiency amplification of Doherty power amplifier (DPA) using symmetric devices.In order to achieve the perfect load modulation,the carrier amplifier output circuit total power length is designed to odd multiple of 90°,and the peak amplifier output total power length is designed to even multiple of 180°.The proposed method is demonstrated by designing a broadband high-efficiency DPA using identical 10-W packaged GaN HEMT devices.Measurement results show that over 51％ drain efficiency is achieved at 6-dB back-offpower,over the frequency band of 1.9-2.4 GHz.     

防破音D类音频功放的设计与应用

随着多媒体便携设备的普及,音频功放已经成为音频部分的标准配置,D类功放以其高品质高效的特点得到了越来越广泛的应用。在便携产品中,音频功放由于输入音乐信号过大或者电源电压过低,会产生削顶失真。采用防破音技术,可以通过自动增益调节技术来提供一个完美的解决方案。文章介绍了常见的防破音技术,提出了一种改进的AGC(自动增益控制)技术在D类功放中的设计与应用。改进的AGC技术通过对PWM输出的采样来判断失真程度,依据失真程度用防破音电路产生的PWM波形来自动调节运放增益,实现最大功率的无失真输出。     

压力对换流阀用压接型IGBT器件功率损耗的影响

功率损耗一直是功率半导体器件应用时备受关注的问题.压接型绝缘栅双极型晶体管(IGBT)器件靠外部压力使内部各个组件保持电气和机械连接,因此压力直接或间接地影响着压接型IGBT器件的功率损耗.将压接型IGBT器件工作时产生的结温作为耦合变量引入,基于此建立了IGBT器件应用于调制脉宽(PWM)换流设备时的功率损耗计算模型,并详细分析了影响功率损耗的各种因素,包括机械压力、开关频率等.以换流阀用3 300 V/1 500 A压接型IGBT器件为例,采用有限元法研究了压力对压接型IGBT器件功率损耗的影响,重点探讨了器件内部各芯片功率损耗的变化情况.结果表明,增加压力一定程度上可以降低压接型IGBT器件的功率损耗,改善器件内部芯片结温分布不均的问题.     

SiC宽带功率放大器模块设计分析

功率放大器是射频前端中的关键部件,宽带是目前功率放大器的主要发展趋势。基于碳化硅(SiC)宽禁带功率器件,利用ADS仿真软件,依据宽带功率放大器的各项指标进行电路的设计、优化和仿真,制作了500~2 000 MHz波段宽带功率放大器,并对放大器进行了性能测试和环境实验。测试结果表明利用该方法设计宽带功率放大器是可行的,SiC宽禁带功率器件具有较宽的工作带宽。     

Enhancement-mode AlGaN/GaN HEMTs fabricated by fluorine plasma treatment

The fabrication of enhancement-mode A1GaN/GaN HEMTs by fluorine plasma treatment on sapphire substrates is reported. A new method is used to fabricate devices with different fluorine plasma RF power treatments on one wafer to avoid differences between different wafers. The plasma-treated gate regions of devices treated with different fluorine plasma RF powers were separately opened by a step-and-repeat system. The properties of these devices are compared and analyzed. The devices with 150 W fluorine plasma treatment power and with 0.6μm gate-length exhibited a threshold voltage of 0.57 V, a maximum drain current of 501 mA/mm, a maximumtransconductance of 210 m S/mm, a current gain cutoff frequency of 19.4 GHz and a maximum oscillation frequency of 26 GHz. An excessive fluorine plasma treatment power of 250 W results in a small maximum drain current, which can be attributed to the implantation of fluorine plasma in the channel.     

功率器件瞬态热特性的激光探针无损测试

报道了一种弱相于激光干涉测温方法．以１．３μｍＩｎＧａＡｓＰ半导体激光为微探针．实时测量了功率晶体管内部结点的瞬态热特性，该方法具有响应速度快、完全非侵人性、空间分辨率高、测温范围广等优点，适合于测试Ｓｉ、ＧａＡｓ、ＩｎＰ等材料的功率电子和光电子器件的瞬态热特性．     

Simulation of wafer-scale GTO thyristors in circuits

A simulation technique that allows the study of large area power devices composed of many outwardly identical elements operating in a realistic power circuit has been developed. Results are presented showing the transient redistribution of current between a pair of GTO thyristor elements during turn-off under the influence of the power circuit. The method is validated by comparing simulated results with experimental measurements. Variations in carrier lifetime. diffusion uniformity, and gate contact position are studied, and they are shown to significantly alter the turn-off performance. Conclusions are drawn concerning the reliability of large area latching power devices with process inhomogeneity     

卫星移动通信终端的低功耗设计

低功耗设计是电子产品设计的重要环节,特别是对工作在野外环境的卫星移动通信手持终端类产品而言,低功耗设计是延长终端待机时间和使用寿命的重要途径。在对通信产品整机及各类组成单元功耗产生原理分析的基础上,分别从整机、单元电路、主要元器件及FPGA代码设计等几个方面入手,讨论了采用通用元器件设计的卫星通信终端的低功耗设计方法,并给出了改进设计后的低功耗设计效果。