基于Pspice的RTD等效模型及其应用电路研究

简要介绍了RTD（共振隧穿二极管）的微分负阻特性及其等效电路,通过对实际AlAs／InxGa1-xAs／GaAs双势垒共振隧穿结构I-V曲线拟合,得出RTD的Pspice等效电路模型参数。采用Pspice软件建立了RTD的等效电路模型,并对其微分负阻特性进行了仿真,仿真结果与测试结果基本吻合。利用所建立的模型,对RTD的基本应用电路：反相器、非门、与非门和或非门进行了仿真模拟。结果表明,该类电路能够正确实现其逻辑功能。最后,对基于RTD的振荡电路进行了仿真,仿真频率与实际测试频率处于同一数量级。由于实测电路寄生参数如串联电阻、电容等的影响,仿真结果与测试结果稍有出入。     

基于共振隧穿二极管的蔡氏电路设计研究

首次提出一种基于共振隧穿二极管的蔡氏电路.利用共振隧穿二极管(RTD)的负微分电阻特性,采用驱动点特性合成的方法,实现了蔡氏电路中的分段线性电阻,通过一组参数的选取,进而实现了蔡氏电路,并用PSpice模拟软件进行了仿真验证.相对于用传统方法实现的蔡氏电路,基于RTD的蔡氏电路具有电路结构更加简洁、便于集成的特点.     

基于共振隧穿二极管的应力检测方法

共振隧穿二极管(RTD)具有微分负阻效应,且其共振隧穿的I-V特性随着廊力的变化而变化,这就是RTD的压阻效应.与半导体材料压阻效应的应用类似,RTD也可用于应力检测.文中研究了两种基于RTD的应力检测方法.在讨论频率-应力检测法的基础上提出了一种新颖的应力检测方法--惠斯通RTD电桥检测法.测试结果表明,基于惠斯通RTD电桥检测法得到的压阻灵敏度随偏置电压可调,町调范围达到三个数量级.     

基于共振隧穿二极管的应力检测方法

共振隧穿二极管(RTD)具有微分负阻效应,且其共振隧穿的I-V特性随着廊力的变化而变化,这就是RTD的压阻效应.与半导体材料压阻效应的应用类似,RTD也可用于应力检测.文中研究了两种基于RTD的应力检测方法.在讨论频率-应力检测法的基础上提出了一种新颖的应力检测方法--惠斯通RTD电桥检测法.测试结果表明,基于惠斯通RTD电桥检测法得到的压阻灵敏度随偏置电压可调,町调范围达到三个数量级.     

RTD与HBT单片集成研究

设计并研制了共振隧穿二极管(RTD)与异质结双极晶体管(HBT)单片集成负阻逻辑单元。详细介绍了逻辑单元的材料结构及工艺流程的设计过程,得到了较好的负阻特性,其开启电压1V左右,峰谷比大于2∶1。同时建立了负阻逻辑单元的模型,通过Pspice模拟结果表明与实际逻辑单元特性吻合良好。     

改进型三值RTD量化器的设计

共振隧穿二极管RTD本身所特有的负阻微分特性使其成为天然的多值器件。介绍了三值RTD和三值RTD+HEMT的伏安特性以及三值RTD量化器和开关序列的工作原理,以RTD开关序列模型为指导思想设计出改进型三值RTD量化器电路,比原电路结构简单,仿真结果验证了设计的正确性。该设计方法不仅可以用于实现更简单和更灵活的三值RTD量化器,还能用于更高值的多值RTD逻辑电路的设计中。     

RTD-HBT高速低功耗环形振荡器的分析

RTD与HBT是高频高速器件,共振隧穿二极管-异质结晶体管(RTD-HBT)环形振荡器有很好的应用前景.详细介绍了RTD-HBT高速低功耗环形振荡器的工作原理,建立了RTD,HBT及RTD-HBT环形振荡器的等效电路模型,并对RTD-HBT环形振荡器用Pspice模拟软件进行了电路模拟.模拟结果与预期结果一致,有助于指导该电路的设计.     

基于RTD 材料结构与参数的RTO 设计与模拟*

首先对THz 波源的共振隧穿二极管(RTD)设计中的关键问题,即从材料与结构出发,对如何提高 RTD 的截止频率和输出功率进行了分析研究,并利用WinGreen 软件,仿真设计出具有高振荡频率和输出功率的 RTD。在此基础上,采用RTD 的共振隧穿理论和缝隙天线的结构模型,利用PSpice 仿真软件构建了包含RTD 材料 与结构参数以及缝隙天线结构参数在内的完整太赫兹振荡器(RTO)的等效电路模型。振荡频率约为1.02THz,输出 功率约为88.2μW,本文工作为今后研究该类器件奠定了基础。     

RTD在压力下的弛豫振荡特性

报道了共振隧穿二极管(RTD)在压力下的弛豫振荡特性.采用Pspice 8.0软件仿真并设计了振荡电路,测得其振荡频率达200kHz.在(100)半绝缘(SI)GaAs衬底上利用分子束外延(MBE)技术生长了AlAs/InxGa1-xAs/GaAs双势垒共振隧穿结构(DBRTS),并采用Au/Ge/Ni/Au金属化和空气桥结构成功加工出了RTD.由于RTD的压阻效应,采用显微喇曼光谱仪标定所加应力大小,对RTD在加压条件下的振荡特性进行了研究,结果表明其弛豫振荡频率大致有-17.9kHz/MPa的改变量.     

RTD在压力下的弛豫振荡特性

报道了共振隧穿二极管(RTD)在压力下的弛豫振荡特性.采用Pspice 8.0软件仿真并设计了振荡电路,测得其振荡频率达200kHz.在(100)半绝缘(SI)GaAs衬底上利用分子束外延(MBE)技术生长了AlAs/InxGa1-xAs/GaAs双势垒共振隧穿结构(DBRTS),并采用Au/Ge/Ni/Au金属化和空气桥结构成功加工出了RTD.由于RTD的压阻效应,采用显微喇曼光谱仪标定所加应力大小,对RTD在加压条件下的振荡特性进行了研究,结果表明其弛豫振荡频率大致有-17.9kHz/MPa的改变量.     

RTD/HEMT多值逻辑(MVL)电路的PSPICE模拟

由共振隧穿二极管(RTD)与高电子迁移率晶体管(HEMT)相并联组成的结构是构成当前RTD高速数字电路常用的基本单元。由于RTD的负阻、双稳和自锁特性,由RTD/HEMT组成的逻辑电路可以大大减少器件的数目,用最少的器件完成一定的逻辑功能。本文对多值逻辑(MVL)中的文字逻辑门用PSPICE模拟软件进行了电路模拟,模拟结果与预期结果一致,并有助于指导该电路的设计。     

共振隧穿器件应用电路概述——共振隧穿器件讲座(2)

在“共振隧穿器件概述”的基础上,对共振隧穿器件应用电路作了全面概括的介绍。首先对共振隧穿器件应用电路的特点、分类和发展趋势作了简述;进一步对由RTDH/EMT构成的单-双稳转换逻辑单元(MOBILE)和以它为基础构成的RTD应用电路,包括柔性逻辑、静态随机存储(SRAM)、神经元、静态分频器等电路的结构、工作原理和逻辑功能等进行了介绍。关于RTD/HEMT构成的更为复杂的电路,如多值逻辑、AD转换器以及RTD光电集成电路等将在本讲座最后部分进行讲解。     

基于共振隧穿二极管的阈值逻辑单元电路设计

共振隧穿二极管作为较为成熟的纳米电子器件,已被广泛应用于高速低功耗电路。由于其具有负内阻特性,单一门电路的功能大大增加,减少了电路的复杂度。在阈值逻辑函数的硬件实现方面,共振隧穿器件也体现出显著的优势。结合谱技术,基于共振隧穿二极管,设计了可实现任意三变量阈值逻辑函数的阈值逻辑单元电路。该电路还可作为阈值逻辑网络中的基本单元,实现复杂的逻辑功能。通过HSPICE软件,仿真验证了所设计电路的正确性。     

Design of nanopipelined adder based on resonant tunneling diode

Due to the negative differential resistance exhibited by resonant tunneling diode (RTD), RTD is suited to implement the threshold gates and increases the functionality of a single gate. Recently, multi-threshold threshold gates (MTTGs) and generalized threshold gates (GTGs) have been proposed, which extend the circuit applications of RTDs. In this paper, a new RTD full adder structure with three logic modules is proposed. Based on this structure, four different adders are built with the combination of different module circuits based on MTTG and GTG. From the simulation results, one of the proposed circuits with GTG structure, namely FA_GG, has the best performance, which reduces 27.7–45.9% power-delay product value in comparison with the previous designs.     

Pspice resonant tunneling diode models and application circuits

Using the analogue behavioural modelling capabilities of Pspice, the current–voltage characteristics and the large-signal equivalent circuit of a resonant tunneling diode are exploited to create a Pspice compatible model for the diode. The model is used, with very few other components, in the simulation of a number of circuit applications, including a sinusoidal wave generator, a frequency multiplier and three state logic circuits. The simulated circuit details, the related waveforms and three-state logic operations are described. The circuits are characterized mainly by their reduced complexity and ease of analysis.     

A vertical resonant tunneling transistor for application in digitallogic circuits

A vertical resonant tunneling transistor (VRTT) has been developed, its properties and its application in digital logic circuits based on the monostable-bistable transition logic element (MOBILE) principle are described. The device consists of a small mesa resonant tunneling diode (RTD) in the GaAs/AlAs material system surrounded by a Schottky gate. We obtain low peak voltages using InGaAs in the quantum well and the devices show an excellent peak current control by means of an applied gate voltage. A self latching inverter circuit has been fabricated using two VRTTs and the switching functionality was demonstrated at low frequencies     

Digital circuit applications of resonant tunneling devices

Many semiconductor quantum devices utilize a novel tunneling transport mechanism that allows picosecond device switching speeds. The negative differential resistance characteristic of these devices, achieved due to resonant tunneling, is also ideally suited for the design of highly compact, self-latching logic circuits. As a result, quantum device technology is a promising emerging alternative for high-performance very-large-scale-integration design. The bistable nature of the basic logic gates implemented using resonant tunneling devices has been utilized in the development of a gate-level pipelining technique, called nanopipelining, that significantly improves the throughput and speed of pipelined systems. The advent of multiple-peak resonant tunneling diodes provides a viable means for efficient design of multiple-valued circuits with decreased interconnect complexity and reduced device count as compared to multiple-valued circuits in conventional technologies. This paper details various circuit design accomplishments in the area of binary and multiple-valued logic using resonant tunneling diodes (RTD's) in conjunction with high-performance III-V devices such as heterojunction bipolar transistors (HBT's) and modulation doped field-effect transistors (MODFET's). New bistable logic families using RTD+HBT and RTD+MODFET gates are described that provide a single-gate, self-latching majority function in addition to basic NAND, NOR, and inverter gates     

RTD多值逻辑电路原理与电路模拟

由共振隧穿二极管(RTD)和高电子迁移率晶体管(HEMT)构成的多值逻辑(MVL)电路可以用最少的器件来完成一定的逻辑功能,达到大大简化电路的目的。共振隧穿二极管和高电子迁移率晶体管属于量子器件,具有高频高速的特点,所以这一逻辑电路有很好的应用前景。本文就多值逻辑电路中的几个典型电路用Pspice软件进行电路模拟,得到了与理论分析一致的模拟结果。     

A flexible logic circuit based on a MOS-NDR transistor in standard CMOS technology

A MOS-NDR (negative differential resistance) transistor which is composed of four n-channel metaloxide-semiconductor field effect transistors (nMOSFETs) is fabricated in standard 0.35 μm CMOS technology.This device exhibits NDR similar to conventional NDR devices such as the compound material based RTD (resonant tunneling diode) in current-voltage characteristics.At the same time it can realize a modulation effect by the third terminal.Based on the MOS-NDR transistor,a flexible logic circuit is realized in this work,which can transfer from the NAND gate to the NOR gate by suitably changing the threshold voltage of the MOS-NDR transistor.It turns out that MOSNDR based circuits have the advantages of improved circuit compaction and reduced process complexity due to using the standard IC design and fabrication procedure.     

Monolithic integration of resonant tunneling diodes and FET's formonostable-bistable transition logic elements (MOBILE's)

A MOBILE (monostable-bistable transition logic element), employing two n-type negative differential resistance devices connected in series, is a functional logic gate with the advantages of multiple inputs and multiple functions. In this paper, a novel approach to achieve MOBILE operation is demonstrated using monolithic integration of resonant tunneling diodes (RTD) and FETs. In our new integration structure, an RTD and FET are connected in parallel. This structure offers several advantages including separate optimization of RTD's and FET's, and flexible circuit design abilities. For a single-input MOBILE gate, inverter operation at room temperature is demonstrated as the evidence of monostable-to-bistable transition