一种高增益级联微波放大器设计与实现

由于某型设备的微波小信号放大需求,需要设计一款高增益微波放大器。本文给出了一种增益大于100 dB的多级放大器设计思路及设计过程,针对此设计进一步讨论了前置放大器、中间级放大器、末级放大器及混频器等各单元的器件的选择,完成了电原理图的设计以及PCB板的布置,最后对该放大器的进行了实测,结果表明该放大器实际总增益在105±0.130.24 dB,增益精度<±0.5 dB,达到了设计要求。目前此放大器已运用于某型发信监测设备中并取得了良好的效果。     

A 60‐GHz power amplifier design with on‐chip tunable load‐matching network and power detect in 90‐nm CMOS

This paper presents a 60‐GHz power amplifier with on‐chip varactor‐based tunable load‐matching networks and an embedded DC temperature‐sensor‐based power detector. The output power can be monitored by the DC temperature sensor, and load‐matching network can be tuned by regulating the control voltage of the varactors, which can be used for correcting unpredictable process, supply voltage, and temperature (PVT) variations and load mismatch. Measured results show that the small‐signal gain of the CMOS power amplifier is up to 6.5 dB at 52 GHz. The power amplifier achieves 5 dBm output P1dB and 7 dBm saturated output power with 4.5% maximun power added efficiency (PAE) at 1 V control voltage. By sweeping the control voltage of the varactors, the power amplifier can obtain the maximun power gain, which can be used to solve the load mismatch. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

大容性负载双极性高压功率放大器设计

设计了一种适合压电陶瓷驱动器等大容性负载动态应用的双极性高压功率放大器,它基于误差放大式原理,采用高压集成运放(PA89)驱动多组并联功率放大级的电路结构,在实现双极性高电压输出的同时具有很强的电流驱动能力.该放大器驱动等效电容为2.5μF的压电陶瓷驱动器时,能实现单端到地-500～+500V高压输出,电压增益40dB...     

Ultra‐low‐noise large‐bandwidth transimpedance amplifier

Equivalent input current noise and bandwidth are the most relevant parameters qualifying a low‐noise transimpedance amplifier. In the conventional topology consisting of an operational amplifier in a shunt‐shunt configuration, the equivalent input noise decreases as the feedback resistor (R_F), which also sets the gain, increases. Unfortunately, as R_F increases above a few MΩ, as it is required for obtaining high sensitivity, the bandwidth of the system is set by the parasitic capacitance of R_F and reduces as R_F increases. In this paper, we propose a new topology that allows overcoming this limitation by employing a large‐bandwidth voltage amplifier together with a proper modified feedback network for compensating the effect of the parasitic capacitance of the feedback resistance. We experimentally demonstrate, on a prototype circuit, that the proposed approach allows to obtain a bandwidth in excess of 100 kHz and an equivalent input noise of about 4 fA/ , corresponding to the current noise of the 1 GΩ resistor that is part of the feedback network. The new approach allows obtaining larger bandwidth with respect to those obtained in previously proposed configurations with comparable background noise. Copyright © 2014 John Wiley & Sons, Ltd.     

An ultra-low-power,low-noise tunable electrocardiogram amplifier

The objective of this research work is to propose an innovative low-power, low-noise, tunable three-stage capacitive instrumentation amplifier, capable of receiving and magnifying the electrocardiogram (ECG) signals. This is done by adding an extra stage to the second stage of the conventional capacitive instrumentation amplifier. The results show similar midband gain with lesser capacitor usage and smaller chip occupancy area with provision of concurrent tunable gain and bandwidth. The proposed amplifier is designed and implemented using TSMC 0.18-μm CMOS technology scale under a 1-V supply voltage with the simulation process carried out using Cadence Virtuoso tool. Post-layout simulation results show that the amplifier has a tunable midband gain of 55 to 65.6 dB, low-cutoff frequency tuned from 377 mHz to 4.5 Hz and high-cutoff frequency tuned from 86.8 to 263.6 Hz. The simulated value of the input-referred noise and noise efficiency factor (NEF) of the amplifier are 9.6 μV_rms and 6.1, respectively, with the total power consumption of 71.2 nW.     

新型功率放大器

简要介绍了甲类和乙类功率放大器原理,分析了其优缺点;详细论述了采用高压运算放大器、跨导技术和甲乙类推挽电路技术所设计电子线路的工作原理;设计了高稳定性、低失真度、甲乙类全互补推挽式功率放大器.     

磁悬浮推力轴承三电平PWM开关功率放大器设计

针对线性功率放大器和两电平开关功率放大器的不足,提出了在磁悬浮推力轴承中采用三电平PWM开关功率放大器,并阐述了三电平PWM开关功率放大器的基本工作原理,设计出一。种新的三电平PWM开关功率放大器。分析表明,这种功率放大器相对于普通的两电平开关功率放大器具有电流纹波小、功率损耗小和抗电磁干扰能力强等优点,并具有良好的动态响应能力。     

磁悬浮轴承功率放大器设计

针对普通的两电平PWM开关功率放大器的不足,提出了在磁悬浮轴承中采用三电平PWM开关功率放大器,阐述了三电平PWM开关功率放大器的基本工作原理,设计出一种新的三电平PWM开关功率放大器。分析表明,这种功率放大器相对于普通的两电平PWM开关功率放大器,具有电流纹波小、功率损耗小和抗电磁干扰能力强等优点,并具有良好的动态响应能力。     

精密微动平面电机线性功率驱动器设计与实现

针对精密微动平面电机电流驱动特点及其功率驱动器高线性度要求,提出了一种高线性的功率驱动器电路设计。该电路采用电流负反馈技术实现电流稳定输出,采用线性大功率单片集成运算放大器OPA541作为功率输出器件,并通过可编程增益运放PGA205实现驱动器增益在线调整。试验结果表明,该功率驱动器最大非线性误差为0.86%,响应频率大于5kHz,满足通常平面电机高线性度和频响要求,为电流输出稳定性等性能的深入研究和系统完善奠定了基础。     

动态神经网络对功率放大器的建模方法及要点

为了使基于神经网络的功率放大器的行为级建模变得更加灵活且易于实现,主要介绍了动态神经网络应用于功率放大器的建模方法及要点。首先简单介绍了动态神经网络的模型和理论,然后说明了对功率放大器进行建模时所采用的方法。重点讲述了动态神经网络对功率放大器建模过程中的几个要点,包括:如何选择动态神经网络隐层神经元数目和导数阶数、如何确立功率放大器输出电压表达式、长期记忆效应的建模、动态神经网络在仿真软件中收敛性等问题。注意这些要点之后,神经网络模型仿真结果会具有良好的收敛性和准确性,这样就能快速地完成功率放大器的建模以应用到实际系统的设计和优化之中。     

基于开关线性复合机理的高效率准线性功率放大器

研究了一种基于开关线性复合机理的高效率柔性波形功率放大器.该功率放大器由开关滤波单元与线性功率单元构成,其末级线性功率单元源自线性功率放大拓扑以确保系统输出高品质波形,同时采用开关滤波单元的输出作为动态跟踪电源对线性功率单元供电,保证了系统的高效率特性.与传统直流供电的线性功率放大器相比,本方案可兼顾高效率与优波输出,系统具有负载鲁棒性的综合优良静动态特性.该柔性功率放大器的设计容量为1kVA,理论分析与实验结果验证了该方案的可行性.     

RFID读写器中高集成度的CMOS功率放大器的设计和分析

介绍了设计的一个采用0．18μm的CMOS工艺的Class—E类的功率放大器。它可以提供最高为20dB的输出功率,以及输出功率在14．5dB的时候可以达到1dB的输出增益,最大的功率附加效率可以达到32．1％。文中还分析了这款功率放大器的频谱特性和RF协议。     

软开关功率放大电路及其在高频电刀中的应用

介绍一种采用软开关技术的功率放大电路.该电路能有效地降低功率放大电路中的开关功率损耗,并在相同电源电压的情况下达到更大的输出功率.推导了该电路输出功率的近似解,给出了电路参数的设计公式,并介绍了它在高频电刀中的应用.仿真实验表明,该电路能输出较大的功率和达到较高的效率,非常适合高频电刀的应用.     

Doherty技术的应用及性能分析

当今无线通信的发展,对基站的功放模块提出了更高要求。更高的效率和更佳的线性指标,是当代技术如EDGE、3G、LTE等所追求的。但对于功放来说,这2个指标却又往往是相冲突的,无法同时满足。本文旨在探讨在功放设计中使用Doherty技术,来提高效率,及对线性指标的影响。先使用等效模型,通过理论计算,得出Doherty技术在提高功放效率方面的作用。通过实验验证,并比较不同功放设计在效率和增益等方面的特性区别。从理论和实验验证了,Doherty可以有效改善功放的效率,但在增益上有轻微衰落。     

新型工频测试电源开关功放的设计

工频测试电源技术的关键取决于功率放大器的性能。针对传统的测试源仍然使用低效的线性功率放大器,本文设计了一种基于D类功放的新型工频测试电源开关功放。经过实物制作及测试,该功率放大器对输入的工频正弦信号进行电压放大,有效值范围为200×80%~200×115%,输出功率不小于20VA,THD不大于2%,能很好地满足实际应用的需求。由于该功率放大器采用BTL结构输出,输出功率仅取决于末级NMOS管,耐压可达直流500V,功率范围大,具有很大应用价值。     

永磁偏置磁轴承三电平PWM开关功放的研究

针对永磁偏置的磁轴承开关功放需要实现低纹波的问题,提出了一种新颖的三电平PWM控制方法．并给出了具体实现电路。通过三电平与传统的两电平PWM开关功放的对比实验验证了该方案的可行性。     

单相电能表检测装置上应用双功率放大器的实践

文中介绍了一种单相电能表检验装置的实现原理,其中一般包含电流放大器,电压放大器,双路电流虚拟负荷电路,误差仪等核心部件。特别介绍了该单相检验中使用的大功率双电流功率放大器的工作原理。该双路电流放大器已经在90表位及以上的单相电能表检验装置上应用,大大提高了电流放大器的可靠性,多表位检验装置的在电力部门计量中心的应用,大大提高了客户的测试效率,也提高了经济效益。     

Low‐noise low‐power front‐end logarithmic amplifier for neural recording system

In this work, a low‐power, low‐noise logarithmic preamplifier for biopotential and neural recording application is presented. The amplifier is based on a linear limit logarithmic amplifier technique, and an active filter as a DC cancellation filter has been included to its input in order to eliminate DC offsets, which are produced at the electrode–tissue interface. This system has been simulated in a UMC standard 90‐nm 1P9M CMOS process. Five dual gain stages are used to produce the required linear limit logarithmic amplifier. The dynamic range of the amplifier is measured to be 48 dB which covers the signals with amplitude from 20 μV to 5 mV. The amplifier consumes 23.5 μW from a 1.2‐V power supply and has a maximum gain of 69.8 dB. The simulated input referred noise is 5.3 μV over 0.1 Hz to 20 kHz. Copyright © 2012 John Wiley & Sons, Ltd.     

A 63‐dB gain OTA operating in subthreshold with 20‐nW power consumption

This paper presents a two‐stage bulk‐driven operational transconductance amplifier operating in weak‐inversion region. The proposed amplifier is upgraded using recycling structure, current shunt technique, positive feedback source degeneration and indirect frequency compensation feedback to enhance transconductance under a reasonable stability. Combining these approaches leads to an ultra‐low‐power high performance amplifier without increasing power dissipation compared to the conventional one. Simulation results in 0.13‐µm complementary metal–oxide–semiconductor technology show the proposed structure achieves a 63‐dB DC gain at 0.25‐V supply voltage with just 20‐nW power dissipation. Copyright © 2016 John Wiley & Sons, Ltd.     

一种基于Wilkinson功率合成的双向放大器

本文提出了一种支持IEEE802.11n标准的高性能双向放大器设计方案,该放大器采用了基于微带线的Wilkinson功率分配/合成网络进行双路功率放大的合成.既保证了大的功率输出,而且解决了传统单功放结构下EVM指标差的问题.文章通过仿真验证了功率合成网络的可行性,并设计山了高输出功率高线性度的双向放大器.实验的测试结...