用于电路模拟的PIN雪崩光电二极管模型

针对PIN结构的特殊性，作了适当的合理近似，考虑了p，n区少子扩散，i区载流子漂移，给出一个完整的PIN雪崩光电二极管电路模型。该模型适于在开发OEIC电路模拟软件中采用，亦可加到现有电路模拟软件中。它可用于直流、交流、瞬态分析。该模型完全适用于PIN结构光电二极管。     

单光子雪崩二极管猝熄电路的发展

单光子雪崩二极管(SPAD)是工作在击穿电压上的雪崩光电二极管(APD).对于极弱光学信号的探测,例如超高音速飞行器早期预警的应用,SPAD可能是理想的探测器选择.SPAD必须与猝熄电路配套工作.基于pn结等效电路模型,分析了适用于SPAD雪崩猝熄的基本电路结构,例如被动、主动以及混合猝熄电路等.对于SPAD器件测试和...     

一种确定弱非线性双端口网络模型参数的新方法

非线性传输函数模型和非线性电流源模型是利用Volterra级数对非线性动态电路建模的两种形式;本文提出一种确定一类弱非线性双端口网络非线性电流源模型参数的方法,它通过测量网络的端口特性来确定其模型参数;这种方法比测量Volterra核的方法简单方便。     

电压阀和电流阀非线性模型的提出及应用

目前的电路分析理论中由于没有非线性电路模型,故对于非线性电路的计算没有形成一个完整的体系。然而在现代的电路中,具有非线性特征的晶体管电路是一种主要的电路。为此,针对晶体管非线性电路,提出了两种能够表示此类非线性元件的电路模型：电压阀和电流阀。利用电压阀和电流阀模型,可对包含晶体管等非线性元件的电路进行电路模型描述,并在此电路模型描述的基础上,能够比较完善地解决晶体管非线性电路的静态、动态分析和计算问题。     

非线性时变互感的瞬态电路模型

基于电路理论和数值积分的原理，导出了非线性时变互感关于Ｂａｃｋｗａｒｄ Ｅｕｌｅｒ和Ｎｅｗｔｏｎ－Ｒａｐｈｓｏｎ算法的瞬态电路模型，将文献［１］中提出的非线性时变ＲＬＣ电路瞬态分析的方法推广到含非线性时变互感的情况，使非线性时变ＲＬＣＭ电路的瞬态分析简化为若干线性时不变电阻性电路的直流分析。     

纳秒脉冲半导体激光驱动器的研究

为了获得高功率、高重复频率的纳秒级光脉冲,介绍了一种基于Marx bank脉冲发生原理的纳秒脉冲激光驱动器的设计,以及设计过程中雪崩晶体管的选取.该驱动器采用一级小雪崩管对触发脉冲进行陡化,由小雪崩管产生的脉冲对Marx bank电路进行触发,以获得大电流窄脉冲,用于驱动半导体激光器.设计所得驱动器的峰值电流为12.5A、半峰全宽为1.51ns、重复频率为100kHz,实现了大幅度纳秒脉冲半导体激光驱动器的设计要求.结果表明,对触发脉冲的陡化,可以降低后一级Marx bank电路的雪崩电压,同时使得脉宽更窄,这将更加有利于驱动半导体激光器.     

基于雪崩三极管的新型并级联脉冲发射技术

针对雪崩三极管构成的Mark级联电路高幅值需要多级级联以及雪崩三极管制作工艺造成的多级电路不能同时触发等缺点,设计了一种特殊的并级联结构,使整个电路在临界雪崩电压值的直流电源供电条件下同时触发,产生信号质量明显优于同级数Marx电路的高幅值、窄脉宽的脉冲信号。文中对雪崩效应的原理进行分析,然后讲述雪崩三极管级联电路的工作原理,在此基础上介绍改进之后的并级联电路,并对其进行仿真分析和实物测试,可以得到上升沿1.9 ns、脉宽4.25 ns、幅值300 V左右的负脉冲,结果表明改进后的脉冲发生装置性能得到很好的改善。     

GaAs MESFET非线性CAD模型综述

介绍了ＧａＡｓＭＥＳＦＥＴ应用在商业软件中的四种非线性ＣＡＤ模型、ＰＳＰＩＣＥ程序中的ＳＴＡＴＺ模型、ＥＥｓｏｆ微波电路模拟程序中的Ｃｕｒｔｉｃｅ对称和不对称模型以及ＱＵＡＳＩ程序中改进的ＳＴＡＴＺ模型。在给出多种模型ＤＣ方程和源漏电容公式的同时，对三种电路模拟程序的应用范围进行了分析。     

雪崩晶体管在纳秒脉冲驱动电路中的应用

介绍了一种可用于半导体激光器、高速摄影、信号处理以及激光雷达的纳秒脉冲驱动电路。利用晶体 管的雪崩效应,通过两级雪崩晶体管阵列,得到了7 ns、6 A的大电流窄脉冲。并对触发脉冲的获得、电路板的 印制进行了简要的介绍。     

SPAD的EDA模型及其在集成淬火电路设计中的应用

针对应用于单光子探测的单光子雪崩二极管建立了EDA电路模型,讨论了模型参数设置及仿真方法,利用此模型分别完成了像素级被动淬火集成电路、像素级主动淬火及快速恢复集成电路的设计仿真,并利用CSMC公司的0.5μm CMOS工艺进行流片制作.结果表明,建立的探测器模型与CMOS电路设计相互兼容,通过合适的电路设计和参数设置,采用以上集成淬灭电路的单光子探测器的最小"盲时"可分别达到100 ns和4 ns.     

Nonlinear Behavior and Bias Modulation of an IMPATT Diode Oscillator

Experimental results of the nonlinear behavior of an IMPATT diode oscillator under free-running and bias-modulated conditions are presented and correlated with theoretical results. Amplitude and frequency behavior of a free-running IMPATT diode oscillator such as: 1) power-frequency characteristic, 2) jump and hysteresis, 3) temperature dependence, 4) harmonic content, and 5) electronic tuning characteristics are discussed. The bias-modulation properties and their relation to the free-running behavior are described. The effects of the operating point, external Q, and injection locking on the modulation properties are presented.     

A large signal analysis of IMPATT diodes

This paper presents results on RF power output and efficiency of IMPATT oscillators obtained from a large-signal model of these devices. The results are obtained from a closed-form solution of the nonlinear equations describing a Read-type IMPATT diode. The closed-form solution is obtained by assuming a short transit time through the drift region compared to the RF period. The solution is used to obtain the large-signal diode impedance. The analysis shows that the power output of an IMPATT diode depends strongly on the series load resistance presented to the active part of the diode and that the change in diode reactance with increasing bias current also depends on the series resistance. Plots of power output as a function of frequency, bias current, and load resistance are presented. Frequency tuning of the oscillator through current variation is also discussed. Experimental results are presented and compared with the theoretical ones wherever possible. The results lead to an improved understanding of such oscillators and are extremely useful in optimizing their performance and determining their limitations.     

Experimental characterisation of avalanche-diode reflection amplifiers and locked oscillators

Qualitative experimental results are presented for a silicon IMPATT diode on the distinction between the undercoupled quenched oscillator, optimised oscillator, locked oscillator, stable amplifier, in relation to the gain, linearity and saturation power. The results are consistent with a nonlinear interpretation of the equivalent diode conductance.     

High frequency noise properties of a double avalanche region (DAR) IMPATT diode

The high frequency noise properties of a double avalanche region (DAR) IMPATT diode consisting of two avalanche layers interspaced by a drift layer have been studied. In view of the fact that SDR IMPATT diode shows a high value of noise figure, one may think that the presence of two avalanche layers in DAR IMPATT diode may lead to a noise figure of the order of 2 or 3 times larger than that of the SDR (or SAR) IMPATT. However, from the study, it has been observed that the DAR IMPATT has the same order of noise as that of SDR IMPATT under operating condition. Since the DAR IMPATT diode with unequal avalanche layer width can be used as microwave oscillator with minimum coupling between the harmonically related frequencies [1], the device may be very useful in the microwave frequency range.     

A nonlinear equivalent circuit for IMPATT diodes

A lumped nonlinear equivalent circuit is developed for Read-type IMPATT diodes, using the carrier transport equations for the device. The validity of this circuit is not restricted to sinusoidal signal waveforms. It can be used for quantitative calculations of device performance as well as for qualitative predictions of the general features of IMPATT diode behavior. The general equivalent circuit is further simplified for the case of sinusoidal excitation and its application is demonstrated by simple examples.     

Power-noise characterization of phase-locked IMPATT Oscillators

IMPATT diode characterization on the basis of output power and the corresponding FM noise figure over a range of operating conditions is presented. The characterization consists of families of power noise curves obtained for a phase-locked IMPATT oscillator where the supply current, load conductance, and the operating frequency are parameters. It is shown that the maximum output power and minimum FM noise are not achieved concurrently. In particular FM transmitter application, it is shown that the best performance for each type of diode was obtained when operated at less than maximum power (and at reduced efficiency) where the system benefits from the attending lower noise. Better system performance, this application, was obtained with the GaAs IMPATT diode. The power-noise characterization defines the optimum operating conditions for an IMPATT diode and provides a valid basis for the comparison of diodes for specific applications.     

Potentials of GaP as millimeter wave IMPATT diode with reference to Si, GaAs and GaN

This paper presents the simulation results of DC,small-signal and noise properties of GaP based Double Drift Region( DDR) Impact Avalanche Transit Time( IMPATT) diodes. In simulation study we have considered the flat DDR structures of IMPATT diode based on GaP,GaAs,Si and GaN( wurtzite,wz) material. The diodes are designed to operate at the millimeter window frequencies of 94 GHz and 220 GHz. The simulation results of these diodes reveal GaP is a promising material for IMPATT applications based on DDR structure with high break down voltage( V_B) as compared to Si and GaAs IMPATTs. It is also encouraging to worth note GaP base IMPATT diode shows a better output power density of 4. 9 × 10~9 W/m~2 as compared to Si and GaAs based IMPATT diode. But IMPATT diode based on GaN( wz) displays large values of break down voltage,efficiency and power density as compared to Si,GaAs and GaP IMPATTs.     

Low noise wide bandgap SiC based IMPATT diodes at sub-millimeter wave frequencies and at high temperature

We have presented a comparative account of the high frequency prospective as well as noise behaviors of wide-bandgap 4H-SiC and 6H-SiC based on different structures of IMPATT diodes at sub-millimeter-wave frequencies up to 2.18 THz. The computer simulation study establishes the feasibility of the SiC based IMPATT diode as a high power density terahertz source. The most significant feature lies in the noise behavior of the SiC IMPATT diodes. It is noticed that the 6H-SiC DDR diode shows the least noise measure of 26.1 dB as compared to that of other structures. Further, it is noticed that the noise measure of the SiC IMPATT diode is less at a higher operating frequency compared to that at a lower operating frequency.     

State-Space Analysis of General IMPATT Diode Small-Signal Lumped Models

The development of a lumped model for small-signal carrier-field interactions in an IMPATT diode results in a set of state equations. Using state-space analysis techniques, the equations are solved for the small-signal impedance of a general IMPATT diode as a function of dc bias current and frequency. Read, p-n, and p-i-n diodes are studied using realistic values for saturation carrier velocities and carrier-ionization rates. Curves indicating the influence of diode physical properties on the small-signal impedance are presented. By combining state equations describing the behavior of the external microwave circuit with the diode state equations, the small-signal oscillation frequency and threshold dc bias current of a coaxial IMPATT oscillator are determined.     

Measurement technique for largesignal admittance of IMPATT diodes

A method is described for determining the large-signal admittance of an IMPATT diode from reflection-coefficient measurements at the output of a well-characterised IMPATT oscillator/amplifier circuit. Measurements at 10 GHz are presented and compared with the computed performance for the diode.