基于OA-OTA的多功能电压模式滤波器

提出了一种由运算放大器（OA）和运算跨导放大器（OTA）构成的多功能电压模式滤波器。适当选定输入输出端，可以实现低通、高通、带通、带阻和全通滤波功能。由于电路仅含有源器件，因而适于全集成，且容易实现电路特性的电调节，中心频率及品质因数的有源灵敏度也很低，PSPICE仿真结果表明，提出的电路方案是可行的。     

脉冲激光探测电路设计

脉冲激光探测电路的设计是激光应用领域的重要内容,根据脉冲激光信号的特点,从探测能力、响应时间、稳定性三方面对脉冲激光探测电路的设计进行研究,重点论述了光电探测系统组成的三个重要组成部分：光电探测器、光电转换电路和探测器偏置电路。深入分析了光电探测器的选型、利用电阻进行光电转换电路的特性以及利用跨导放大器进行光电转换电路的特性,对于激光探测系统的设计有一定参考价值。     

Nonlinear transport phenomena and mode locking in millimetre-wave Gunn-instability structures

The nonlinear behaviour of drift-diffusion transport model of the 3 µm GaAs Gunn-effect structure is analysed here. It is shown that the correct choice of the v(E) form and its exact approximation is necessary. Increase of the v(E) dependence steepness in the region above the threshold leads to dissolution of the dipole domains before anode contact. A local extremum appears on the dependence of the transit frequency on the applied dc voltage. This complicates mode-locking processes when a driving microwave signal is applied. The effective length of the transit region quasiperiodically changes, similarly to threshold modulation in relaxation oscillator models. The nonlinear interaction of oscillations leads to multiplication of the current oscillations period and complication of the terminal current shape. The quasiperiodic microwave signal outside the phase-locking regions has different upper and lower envelopes, leading to the appearance of an additional high-frequency component in the signal spectrum. The principal phase-locking region boundaries are defined by the golden mean proportions. Some results of the experimental investigations of Gunn oscillator nonlinear dynamics in the 40–55 GHz frequency band are also given here.     

Electronically tunable mutually coupled circuit using only two active components

A new circuit for realisation of the mutually coupled circuit, which is also called the synthetic transformer, is proposed. The proposed circuit uses two current controlled current conveyor transconductance amplifiers (CC-CCTAs), one grounded resistor and two grounded capacitors. The primary self-inductance, the secondary self-inductance and the mutual inductance can be independently controlled and can be tuned electronically by changing the biasing current of the CC-CCTAs. It uses two grounded capacitors which are suitable from the point of integrated circuit implementation. It has a good sensitivity performance with respect to tracking errors and passive components. The validity of the proposed circuit is demonstrated by PSpice simulations.     

基于最小电流选择的运算放大器设计

设计了一种工作电压为3V恒跨导满幅CMOS运算放大器,针对轨对轨输入级中存在的跨导不恒定和简单AB类输出级性能偏差这2个问题,提出了利用最小电流选择电路来稳定输入级的总跨导;浮动电流源控制的无截止前馈AB类输出级实现了运放的满幅输出,同时减小了交越失真。该电路通过HSpice进行仿真验证,在0～3V输入共模范围内,输入级跨导的变化小于3.3%,开环增益为93dB,单位增益带宽为8MHz,相位裕量为66°。     

基于生物应用的低截止频率5阶Gm-C低通滤波器

设计了一款基于生物应用的截止频率为38.49 Hz的5阶跨导电容(Gm-C)低通滤波器.首先利用电流互抵技术设计实现了一款低Gm的运算跨导放大器(OTA),并基于此OTA,采用无源电感电容(LC)网络模拟法设计了一款5阶椭圆滤波器.最后基于华虹宏力0.35 μmCD350 60 V/80 V工艺应用Spectre仿真工具对滤波器进行仿真.结果表明,所设计的低通滤波器可以实现非常陡峭的过渡带,并在50 Hz工频信号处衰减达-43.812 dB;阻带衰减为-33.18 dB;通带内平均噪声为352.0 μV·Hz-1/2;总谐波失真为-56.24 dB;3.3 V电源电压下,5阶滤波器总功耗仅为11.73 μW.所设计的滤波器可以有效采集频率极低的生物信号并且滤除干扰信号.芯片面积为1 200 μm×728.μm.     

RTD/HEMT串联型共振隧穿三极管的设计与研制

对RTD/HEMT串联型共振隧穿三极管进行了设计和研制.测量结果表明:最大电流峰谷比为17.6∶1,棚压对峰值电压调控能力在1.5～7.7范围内,-3dB截止频率为4GHz,此种器件可与HEMT在结构和工艺上兼容,可应用于HEMT高速电路.     

应变Si沟道异质结NMOS晶体管

通过参数调整和工艺简化,制备了应变Si沟道的SiGe NMOS晶体管.该器件利用弛豫SiGe缓冲层上的应变Si层作为导电沟道,相比于体Si器件在1V栅压下电子迁移率最大可提高48.5%.     

基于0.25μm CMOS工艺的1.8V Rail-to-Rail运算放大器

采用TSMC0．25μm CMOS工艺，设计实现了一种低功耗、高增益带有恒跨导输入级的Rail—to—Rail运算放大器。基于BSIM3V3 Spice模型，采用Hspice对整个电路进行仿真，在1．8V的单电源电压工作条件下，直流开环增益达到108．6dB，相位裕度为57．2度，单位增益带宽为5MHz，功耗为0．23mW。     

一种用于水听器电压检测的模拟前端电路

提出了一种用于水听器电压检测的模拟前端电路,包括低噪声低失调斩波运算放大器,跨导电容(gm-C)低通滤波器,增益放大器三部分主体电路;低噪声低失调斩波运算放大器用于提取水听器前端传感器输出的微弱电压信号;gm-C低通滤波器用于滤除电压信号频率外的高频噪声和高次谐波;最后经过增益放大器放大至后级模数转换器的输入电压范围,输出数字码流;芯片采用台积电(TSMC)0.18μm单层多晶硅六层金属(1P6M)CMOS工艺实现。测试结果表明,在电源电压1.8 V,输入信号25 kHz和200 kHz时钟频率下,斩波运放输入等效失调电压小于110μV;整体电路输出信号动态范围达到80 dB,功耗5.1 mW,满足水听器的检测要求。