用变温法测量RTD串联电阻

用变温法测量了GaAs基共振隧穿二极管(RTD)器件的串联电阻参数.与网络分析仪法不同,变温法是通过测量RTD器件在不同温度下的I-V特性曲线,用数学方法求解曲线特定区域的相关参数得到串联电阻值.为了便于对比,设计并研制了两种发射极面积的RTD器件,经测量发现,发射极面积对于RTD的串联电阻有较大影响.对其产生原因进行了详细的分析,为RTD在高频电路中的应用奠定了基础.     

共振隧穿二极管基础电路的模拟与分析

简单介绍了RTD的器件性和器件模型，用HSPICE模拟出RTD与电阻、MOS晶体管、RTD本身结合的电路特性。通过对不同电路参数I-V特性的模拟和分析，为理解RTD器件机理和构造复杂电路提供了初步的基础。     

RTD的器件模型和模拟——共振隧穿器件讲座(9)

阐述了电路模拟在设计和研制大规模集成过程中的必要性和重要意义,器件模型在电路模拟中的重要性以及器件模拟与器件模型的关系;在器件模拟通用软件形成过程的基础上重点讨论了RTD的器件模型、器件模拟和电路模拟软件SPICE三个课题;介绍了基于物理参数I-V方程RTD模型和高斯函数、指数函数RTD直流模型;利用ATLAS器件模拟通用软件对RTD进行了器件模拟,得到了势垒和势阱宽度、E区掺杂浓度等对RTDI-V特性的影响;以包含RTD电路的SPICE电路模拟中的文字逻辑门为例,通过电路模拟验证了其逻辑功能,对设计该电路起到指导和参考作用。     

一种高性能InP基谐振隧穿二极管的研制

设计并用分子束外延技术生长了InP基InGaAs/AlAs体系RTD材料,采用传统湿法腐蚀、光学接触式光刻、金属剥离、台面隔离和空气桥互连工艺,研制出了具有优良负阻特性和较高阻性截止频率的InP基RTD单管，器件正向PVCR为17.5,反向PVCR为28,峰值电流密度为56kA/cm^2,采用RNC电路模型进行数据拟合后得到阻性截止频率为82.8GHz，实验为今后更高性能RTD单管的研制,以及RTD与其他高速高频三端器件单片集成电路的设计与研制奠定了基础。     

共振隧穿二极管基础电路的模拟与分析

简单介绍了RTD的器件特性和器件模型 ,用HSPICE模拟出RTD与电阻、MOS晶体管、RTD本身结合的电路特性。通过对不同电路参数I V特性的模拟和分析 ,为理解RTD器件机理和构造复杂电路提供了初步的基础     

一种高性能InP基谐振隧穿二极管的研制

设计并用分子束外延技术生长了InP基InGaAs/AlAs体系RTD材料,采用传统湿法腐蚀、光学接触式光刻、金属剥离、台面隔离和空气桥互连工艺,研制出了具有优良负阻特性和较高阻性截止频率的InP基RTD单管.器件正向PVCR为17.5,反向PVCR为28,峰值电流密度为56kA/cm2,采用RNC电路模型进行数据拟合后得到阻性截止频率为82.8GHz.实验为今后更高性能RTD单管的研制,以及RTD与其他高速高频三端器件单片集成电路的设计与研制奠定了基础.     

共振隧穿二极管基础电路的模拟与分析

简单介绍了RTD的器件特性和器件模型,用HSPICE模拟出RTD与电阻、MOS晶体管、RTD本身结合的电路特性.通过对不同电路参数I-V特性的模拟和分析,为理解RTD器件机理和构造复杂电路提供了初步的基础.     

RTD交流小信号等效电路模型——共振隧穿器件讲座(7)

RTD交流小信号等效电路模型是分析RTD交流特性的基础,也是用网络分析仪测量S参数,拟合提取交流参数和计算截止频率fR的依据。精确、合理的等效电路模型有助于深入理解RTD的工作原理,也对RTD器件和RTD集成电路的设计起重要的指导作用。介绍了四种常见而又重要的RTD交流小信号等效电路模型。     

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。     

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.     

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。     

Analysis of frequency divider RTD circuits

The behavior of a novel circuit topology able to implement a frequency divider is studied. This circuit is composed of a resonant tunnelling diode (RTD), an inductor, and a capacitor, so it exhibits a very high operating frequency and low power consumption. It employs the period-adding sequences which appear in its bifurcation diagram to perform the frequency division. Compared to a previously reported similar circuit, it has wider operation windows and a higher division factor for the driver frequency, while maintaining the extremely high operating frequency, its simplicity, and the division factor tunability through the selection of circuit parameters. Simulation results using the HSPICE RTD model from project LOCOM as well as several realistic parasitics elements are given, which confirm the theoretical capabilities previously analyzed.     

Improving the peak current density of resonant tunneling diode based on InP substrate

Resonant tunneling diodes (RTD) have the potential for compact and coherent terahertz (THz) sources operating at room temperature, but their low output power severely restricts their application in THz frequency range. In this paper, two methods are adopted to increase the peak current of RTD for enhancing its output power. First, different metal contact systems (including Pt/Ti/Pt/Au and AuGe/Ni/Au) for RTD contact are introduced, and a higher current of RTD with Pt/Ti/Pt/Au contact demonstrates the superior contact characteristic of Pt/Ti/Pt/Au contact system. Second, the double barrier structure (DBS) of RTD is well designed to further improve the characteristic of RTD, and a high peak current of 154 kA/cm² is achieved at room temperature. The improved peak current is very beneficial for increasing the output power of RTD oscillator.     

InP基谐振隧穿二极管的研究

谐振隧穿二极管(RTD)具有高频、低功耗、负阻、双稳态、自锁等优点,在超高速数字电路领域具有非常好的应用前景.加之InP材料固有的优越特性,使得InP基谐振隧穿器件成为目前研究的重点.研究并试制了InP基RTD实验样品,对其直流特性进行了测试分析,器件的最大电流峰谷比(PVCR)达到了17.8.     

Equivalent circuit parameters of resonant tunneling diodesextracted from self-consistent Wigner-Poisson simulation

The equivalent circuit parameters of resonant tunneling diodes (RTD) are extracted from numerical simulation results for RTDs. The RTD models used in this paper are double barrier structures. The influence of the resonant tunneling structure (RTS) parameters, such as the height of barriers, the width of the quantum well, the width of the spacers, and the width of the barriers, on the device parameters are systematically discussed. The effects of device temperature on device parameters are also discussed. Scattering between electrons and phonons greatly affects device parameters and thereby the function of the RTDs. Physical explanations about how the structure parameters and device temperature influence the device parameters are provided. Based on the analysis results, a general way to get an RTD oscillator with a higher maximum frequency is suggested     

High frequency simulation of resonant tunneling diodes

The small and large-signal response of the resonant tunneling diode at high-frequencies is studied using a quantum simulator. The Poisson and Schrodinger equations are solved self-consistently for each harmonic using the harmonic balance technique. This ensures that the total current, consisting of the displacement plus conduction currents, is conserved across the device for each harmonic. The RTD exhibits an increased capacitance in the negative differential conductance (NDC) region in agreement with experimental data. As recently proposed this capacitance increase results from the formation of an emitter well capacitor when the well discharges. The derivation of the RTD capacitance from a quasi-static analysis using the differential variation of the de charge in the RTD is shown to be not applicable because the RTD well charges through the cathode but discharges through the anode. The frequency dependence of the conductance and susceptance is similar to reported experimental data. A large frequency dependence of the admittance is only observed when the RTD is biased in the negative differential conductance (NDC) region. These calculations predict an effective reduction of the RTD conductance and capacitance at high-frequency in the NDC region. This effect can be modeled using a quantum inductance in series with the negative resistance of the RTD as recently proposed. Due to the simultaneous reduction of both the conductance and the capacitance at high-frequency in the NDC region the maximum frequency of oscillation does not differ much from its estimate using the low frequency conductance and capacitance. The large-signal response at high-frequency of an RTD biased in the negative differential region is also presented in this paper. The large-signal negative-conductance is shown to decrease with both increasing frequency and ac voltage