双向负阻晶体管张弛振荡器分频锁相特性的研究

本文用简单模型描述了双向负阻晶体管(BNRT)张弛振荡器在周期冲激作用下的分频锁相特性。对于任何分数p/q,给出了在参数空间中分频锁相区的普遍的分析表达式。对于BNRT张弛振荡器进行了分频锁相实验,实验结果与计算相符,说明理论分析是正确有效的。     

双向负阻晶体管张弛振荡器的研究

本文研究了双向负阻晶体管(BNRT)张弛振荡器的分段线性(具有四段折线和三段折线)动力学模型。给出了电路和动态方程。讨论了张弛振荡器的一些性质。实验结果与计算结果一致,表明这种动力学模型是适当而有效的。     

三端双向负阻晶体管的二维数值模拟及分析

对双向负阻晶体管(BNRT)的三端特性进行了数值模拟，得到了器件S型负阻曲线。根据BNRT不同工作状态下的内部电势、电子浓度和空穴浓度分布，解释了其S型负阻特性的产生机理。模拟分析了负阻曲线随控制电压变化的情况。结果表明，随控制电压的增大，转折电压、转折电流和维持电压均增大。最后，对不同结构和工艺参数的三端BNRT进行了模拟，总结出器件结构和工艺参数对负阻特性的影响。     

三端双向负阻晶体管的模拟与实验

对双向负阻晶体管(BNRT)的三端特性进行了研究.根据器件模拟得到了器件内部电势和电场分布,解释了S型负阻特性产生机理.分别从模拟和实验得到了输出负阻曲线随控制极电压变化的情况,结果表明,随控制电压的增大,转折电压、转折电流和维持电压均增大.模拟结果和实验结果一致.BNRT的三端化实现,克服了两端应用的诸多缺点,大大增加了它在高速脉冲电路中的应用灵活性     

三端双向负阻晶体管的模拟与实验

对双向负阻晶体管(BNRT)的三端特性进行了研究.根据器件模拟得到了器件内部电势和电场分布,解释了S型负阻特性产生机理.分别从模拟和实验得到了输出负阻曲线随控制极电压变化的情况,结果表明,随控制电压的增大,转折电压、转折电流和维持电压均增大.模拟结果和实验结果一致.BNRT的三端化实现,克服了两端应用的诸多缺点,大大增加了它在高速脉冲电路中的应用灵活性.     

GaAlAS DH激光器若干参数的测量和分析

本文扼要介绍了GaAlAs DH激光器若干参数的测量方法和测试结果。在实验的基础上,就偏振特性、伏安特性、瞬态特性等问题进行了较详细的定性分析。解释了一些现象,提出了一些看法。主要结果如下:偏振特性更能反映自然解理腔面GaAlAs DH激光器的本质,因而偏振好坏可能成为这种激光器好坏的一个重要判据。正向导通电压和激光器的峰值波长有关;反向击穿电压可能和作用区的宽度有关。“正、反向都通但仍能发光”的器件,可以用加反偏压的方法治好。在偏振好的器件上,仍能观察到张弛振荡、尖峰效应、低频阻尼振荡、自脉动和顶部“噪声”等现象。不封装的器件,腔面容易被腐蚀。     

光电双向负阻晶体管的研制及特性分析

首次对双向负阻晶体管(BNRT)进行了光敏化,设计并研制出既有光敏特性又有“S”型负阻特性的一种新型光电开关器件——光电双向负阻晶体管(PBNRT)。介绍了器件的设计和研制过程;测量分析了其J—V特性与光强和栅极电压的关系;测量了光电开关的时间常数并进行了分析讨论。     

由RTD/MOSFET构成的压控振荡器的设计与实现

提出了一种基于负阻器件共振隧穿二极管(RTD)与MOSFET结合的新型压控振荡器(VCO),并利用了高级设计系统(ADS)软件对该振荡器的可行性进行了电路仿真,利用分立RTD、MOSFET器件实现了此种VCO,实际调频范围在20～26 MHz之间。RTD与三端器件的连接方式不同可呈现不同的调制I-V特性,这种调制特性对基于RTD的振荡电路的频率也会产生影响。通过深入研究这种调制对振荡电路频率产生的影响,得到多种不同于常规方法的电压控制频率方式,其中一些具有很好的线性度。因此该电路的研究对于RTD在高频、高速振荡电路中的进一步应用具有重要意义。     

四维系统中多涡卷混沌吸引子及其同步的研究

通过四维系统中的多涡卷混沌吸引子的研究，提出了一个简便数学公式来确定产生多涡卷的分段线性伏安特性的转折点电压，该方法可产生任意个数的涡卷。介绍了以此方法确定了产生6-8涡卷的混沌振荡电路，并对6-8涡卷的混沌振荡电路进行了仿真。最后用脉冲同步法对5涡卷混沌振荡电路进行了同步仿真研究。     

连续气体放电器件电源的设计

本文从气体放电器件的伏安特性出发，利用二点法求出He—Ne，CO2，Xe等气体放电伏安特性负阻段的解析式，进而对放电电路进行设计。     

RESEARCH ON THE RELAXATION OSCILLATOR WITH BNRT

A piecewisely linear(with three or four segments)dynamic version for relaxation oscillations in acircuit with bidirectional negative resistance transistor is studied.The circuit and dynamic equation are given andsome properties of the relaxation oscillations are discussed.Experimental results agree well with the computations,showing that the dynamic model is adequate and useful.     

半导体抽运Nd:YAG激光器强度噪声抑制的研究

为了降低半导体抽运固体激光器的弛豫振荡噪声,提高其输出功率的稳定性,采用光电负反馈的方法来抑制半导体抽运的固体激光器的强度噪声,并对激光器强度噪声的理论特性进行了分析。根据理论分析结果设计了比例-积分-微分反馈控制电路,通过运用该反馈电路对激光器进行强度噪声抑制实验,得到了比较理想的实验数据,即当抽运功率为700mW、弛豫振荡峰频率为300kHz时,弛豫振荡峰值处和低频区域强度噪声分别降低了45dB和15dB;当抽运功率为550mW、弛豫振荡峰值为250kHz时,弛豫振荡峰值处和低频区域强度噪声分别降低了40dB和10dB。结果表明,该反馈控制电路能够有效地降低半导体抽运固体激光器的强度噪声,提高激光器输出功率的稳定性。     

DC instability of the series connection of tunneling diodes

An oscillator with a series connection of tunneling diodes produces significantly higher power than a single diode oscillator. However, a circuit with series-connected tunneling diodes biased simultaneously in the negative differential resistance (NDR) region of the I-V curve is dc unstable. This dc instability makes the series connection oscillator fundamentally different from a single diode oscillator. Associated with the dc instability are the phenomena of minimum oscillation amplitude and frequency. Due to the minimum oscillation amplitude, it is critical to provide the impedance match between the oscillator circuit and the series connection at the desired oscillation amplitude level. An in depth, comprehensive analysis of the dc instability is given here. Based on this analysis, a numerical procedure is developed to accurately predict the minimum oscillation amplitude and frequency. Time domain simulations which give further insight into series-connection oscillator behavior are discussed. The effect of increasing the number of diodes on the oscillator performance is explored as well. Based on numerical and simulation results, oscillators with several tunnel diodes connected in series were designed and tested. Experimental results that confirm the existence of the minimum oscillation amplitude are presented for oscillators with two, three, and four tunnel diodes     

Effects of hot-carrier stress on the performance of the LC-tank CMOS oscillators

The effects of hot carrier stress on a fully integrated negative resistance LC-tank CMOS oscillator are investigated. The major effect is the decrease of the amplitude of the oscillation due to degradation in the I-V characteristics of the MOSFETs. The oscillator phase noise increases with stress duration since the amplitude of the oscillation decreases. A change in the biasing of the circuit due to the stress affects the parasitic capacitances in the circuit which in turn cause a slight change in the oscillation frequency.     

基于单电子晶体管的动态全加器电路设计

基于单电子晶体管的I-V特性,运用CMOS动态电路的设计思想,提出了一种基于单电子晶体管的全加器动态电路,利用SPICE对设计的电路进行了仿真验证,分析了电荷分享问题.相对于静态互补逻辑电路的设计方法,基于单电子晶体管的动态逻辑电路不仅克服了单电子晶体管固有的电压增益低的缺点,而且器件数目也大幅减少.多栅SET的使用可以减少电荷分享问题对动态电路的影响.     

Transient analysis of two semiconductor devices under circuit-loaded operation conditions

A new method of numerical analysis for semiconductor devices is described. The analysis is carried out by solving a set of fundamental equations which govern the device characteristics and the circuit equation which indicates the circuit condition, simultaneously. Here, instead of Poisson's equation used as one of the fundamental equations in most reported analyses, a "current equation" is used, which represents the device current consisting of conduction current and displacement current. Current equation can be directly substituted into the circuit equation, so the solution obtained from this analysis has self-consistency between device characteristics and circuit condition, Furthermore, the time variations for I-V characteristics, carrier concentration distribution, and electric field distribution for an individual device can be obtained. As a calculation example, the transient characteristics of two diodes with reverse biased condition are calculated. Avalanche oscillation is found for both diodes with opposite phase after avalanche breakdown.     

高功率固体激光器激活介质的非辐射弛豫热吸收

分析了高功率固体激光器中激活介质的热吸收特征,建立了连续运转条件下激活离子的非辐射弛豫模型,给出激活介质非辐射弛豫热吸收对激光振荡的依赖关系,以及激光振荡条件对激活介质屈光度的影响,实验结果与理论模型分析一致。     

Accurately measuring current-voltage characteristics of tunnel diodes

This paper provides an approach to monitor oscillation status in tunnel diode measurement circuits-by measuring the second derivative of the current-voltage (I-V) characteristic curve while doing I-V curve measurement. The method of using the second derivative to detect oscillations works even when the oscillation frequency is ultrahigh or the oscillation amplitude is very small, e.g., below 10 mV. In this paper, the experimental principle of the tunneling spectroscopy was extended to measurement circuits with the presence of internal oscillations, in contrast to the conventional tunneling spectroscopy, which normally does not deal with internal oscillation. The numerical relationships between the measured average values of transient derivatives and the derivatives of the average current are derived: The average values of the transient first and second derivatives are shown to equal the derivatives of the average current. These relationships serve as the foundation for the authors' experiments. The typical oscillation characteristics in the curves of the first and the second derivatives are used to detect the presence of oscillations and the bias voltage range of oscillation in the I-V curve. The monitor of oscillation status during measurements provides the tester the confidence in the measurement data and whether it is necessary to improve the test circuit further. Finally, benefited from free-of-oscillation, the indirect tunneling current contributions arising by 121-mV (TO+O) two-phonon combination, 144-mV (TA+O+O) and 181-mV (TO+O+O) three-phonon combinations at the negative differential resistance region are observed from a silicon Esaki tunnel diode at 4.2 K.