无线传输系统中低噪声放大电路的设计

介绍射频功率放大器的基础理论和技术参数,并根据设计要求选取合适的低噪声放大器.给出了射频功率放大电路的设计方案,并根据系统接收端无线信号特点,设计低噪声功率放大电路,从而提高无线传输系统的接收灵敏度.并满足冲击波测试对无线传输距离的要求.     

ZigBee无线网络功放的设计与仿真

ZigBee是一种低速无线个域网技术,适用于通信数据量小,速度相对较低,并且功耗低的场合。组网灵活是其一大特点,但是由于传输距离比较短,从而限制了其发展。基于ZigBee无线通信网络技术,提出了一种通过增大发射信号功率、提高接收信号灵敏度来增加系统传输距离的方法。使用ADS软件主要对功率放大电路和低噪声放大电路进行仿真与性能优化,从而得出最佳设计方案。仿真结果基本满足了系统功率和增益的要求。     

VHF跳频电台接收机射频前端的仿真设计与研究

通过对VHF跳频电台接收机射频前端设计指标和具体结构的介绍,运用Agilent公司的射频设计仿真软件ADS,对整个接收机射频前端电路进行仿真和电路设计,构建了一个由保护电路、跳频预选滤波器、低噪声放大器和自动增益控制电路组成的射频前端电路模型,并对其进行仿真.最后的实验结果表明,所设计的射频前端的性能指标达到了系统的设计要求,并有所提高.     

微波低噪声放大器的设计与仿真

低噪声放大器在接收系统中能降低系统的噪声和接收机灵敏度,是接收系统的关键部件。文中按照低噪声放大器电路的设计要求,完成了2GHz基站前端射频低噪声放大器的电路设计,并通过ADS仿真软件对电路进行仿真和优化。最终表明,采用本方案设计的LNA增益约为15dB,噪声系数约为1．2dB,性能稳定,完全达到了通信接收机中对LNA指标的要求。     

一种基于GaAs FET的S波段功率放大和整流双向电路

设计了一种基于砷化镓场效应管(GaAs FETs)的S波段微波功率放大和整流双向电路,分析了微波功率放大电路与整流电路之间的类似性。利用ADS对其进行仿真,并进行实验验证。该电路具有微波功率放大功能,增益和功率附加效率分别为11.9 dB和55%,输出功率达28.9 dBm。该电路同时具有将微波转换为直流的功能。当电路偏置在C类状态下,微波输入功率为30 dBm,且直流负载为55 Ω时,获得了75.6%的整流效率。电路正向放大反向整流的特性可望应用到双向微波无线能量传输系统中。     

低功耗微弱信号无线传输系统

本文针对微弱信号的幅度小,并且容易受到外界噪声和电磁干扰的影响,设计了单电源低噪声差分放大器来放大微弱信号。针对微弱信号无线传输问题,选用蓝牙电路完成无线传输,蓝牙工作在面向连接的工作模式下,将微弱信号无线传输到智能手机上。为了使得放大电路蓝牙电路能正常工作,设计供电电路与充电电路,供电电路的输入为单电源电压,其输出为对称的正负电压。加工制作了微弱信号无线传输电路板,验证了系统的各部分电路的功能。在此基础上最小化电路,降低功耗,节省空间,缩减尺寸,将原来的矩形板改为圆形板,单面焊接转化为双面焊接,完成了最终电路板。     

nRF903在粮库测温系统中的应用

在简要介绍了无线射频通信芯片nRF903和单总线温度传感器DS18B20的性能和特点的基础上,根据粮库测温系统的特殊现场要求,利用低功耗、高性能的单片机LPC932为核心构成了一个多点的无线粮库测温系统,具体介绍了系统中测温器的硬件接口电路、温度传输协议和无线收发流程。     

超高频射频识别阅读器的高线性低噪声前端

根据超高频段射频识别的协议要求、结合论文所提出的正交直接变频无线收发机架构,对阅读器接收路径所需的系统噪声系数、输入线性度要求做出分析。给出了同时具有低噪声系数、高线性度特点的三级紧凑式射频前端,该电路能够承受标签背散射机制所引起的大信号带内自阻塞干扰。电路采用IBM 0.18μm CMOS 7RF工艺制作,当从3.3V的电源电压上抽取6.9mA电流时,该射频前端可以获得13dBm的输入线性度与23 dB的最大噪声系数。     

基于AT89S52和nRF24L01的无线温度监测系统

基于AT89S52单片机和射频芯片nRF24L01模块设计了一种的低功耗无线温度监测系统。该系统能实现在恶劣条件下的实现对温度的远程采集和无线传输,并可利用RS-232串口与PC联机。它具有电路简单、功耗低、数据传输可靠性高等特点,能满足恶劣条件下的环境温度监测的要求。     

基于FPGA的射频收发前端系统设计

以Xilinx公司的V5系列FPGA芯片为研究对象,设计实现了一种基于VPX标准的6U射频收发前端信号处理系统。该系统主要由控制电路和射频电路组成,控制电路主要完成对外、对内的接口通信功能以及核心器件的控制。射频电路主要完成信号滤波、放大、正交上变频、功率放大等。设计的系统支持串行Rapid IO高速数据传输,为数据的高速交换提供了可能,满足了系统对带宽和数据处理能力的要求,经过验证系统的各项性能指标符合设计要求。     

Tournament-Shaped Magnetically Coupled Power-Combiner Architecture for RF CMOS Power Amplifier

A tournament-shaped magnetically coupled power-combiner architecture for a fully integrated RF CMOS power amplifier is proposed. Various 1 : 1 transmission line transformers are used to design the power combiner. To demonstrate the new architecture, a 1.81-GHz CMOS power amplifier using the tournament-shaped power combiner was implemented with a 0.18-mum RF CMOS process. All of the matching components, including the input and output transformer, were fully integrated. The amplifier achieved a drain efficiency of 38% at the maximum output power of 31.7 dBm.     

Optimizing the power-sensitivity trade-off in TRF receivers

There is an inevitable trade-off between the sensitivity of an RF receiver and its total power consumption, meaning that in order to design a receiver with a high sensitivity, more power must be dissipated. Ultra-low power receivers in general and wake-up receivers in particular require a sensitivity of better than ?70 dBm while the power consumption should be as low as possible at the same time. Therefore, obtaining an optimum point where these two design specifications are met is of great interest. In this work, we present a design methodology for the tuned radio frequency (TRF) receiver topology, which yields an optimum power-sensitivity product for given design parameters. The most interesting outcome of this study is finding an optimum number of amplifier stages at the front-end of the receiver that leads to a minimum power-sensitivity product. It is shown through analytical/graphical approach in Matlab that the optimum number of stages resulting in the minimum power-sensitivity product can be different from the optimum number of amplifier stages leading to the maximum overall gain-bandwidth product. These results are also verified through circuit-level simulation with Cadence Spectre for practical design parameters. According to our study, the minimum power-sensitivity product occurs for a two-stage amplifier with moderate gain at the front-end of the TRF receiver.     

一种短波有源天线供电转换器的设计

设计了一种短波有源天线供电转换器,利用直流信号和高频信号的频率差异,通过一条传输线路完成射频信号的传输和天线放大器的直流供电,根据射频器件的高频特性实现2路信号的隔离和复用,采用ADS射频仿真软件建立仿真模型。仿真结果显示在工作带宽内射频阻抗特性和直流电压平稳。制作了一台四通道短波有源天线供电转换器,在1．5～30 M Hz的工作频率范围内实测结果和仿真计算结果相吻合,可与宽带接收机实现良好的匹配。同时,供电转换器各通道之间幅度和相位一致性很好,还可满足一些有源阵列天线的需求。     

基于Video+PON高性能CATV光接收机的设计

针对Video+PON的FTTH应用方案,介绍了一款内置WDM的CATV光接收机的设计.通过对光电转换和放大电路的优化设计,该款CATV光接收机具有优异的接收灵敏度和输出性能指标,加之体积小、功耗低、性价比高等特点,会有很好的应用前景.     

射频与毫米波功率放大器新进展

近年来,随着5G 演进和未来6G 技术的研究与突破,以及在应用端如物联网、智能驾驶等领域的技术迭代升级,都对射频与毫米波系统的设计提出更多的需求和更高的要求。功率放大器作为发射机的关键部件,其特性直接影响发射系统的信号覆盖距离、传输质量和功耗等指标。为了研制高性能射频与毫米波功率放大器,提出了各种新技术。文章将从有源放大器、无源网络的传输线型实现、系统电路架构三方面对功率放大器取得的新进展进行介绍。     

基于ANSYS的射频功率放大器热特性研究

论文首先仿真设计了一款射频功率放大器,接着构建了该射频功率放大器热特性分析模型,并采用有限元方法分析了该射频功率放大器热特性,然后研究了增加过孔以及不同覆铜层厚度、环境温度、耗散功率四种情况对射频功率放大器的温度、热应力和热形变的影响,最后基于上述分析结论加工制作并测试了该款射频功率放大器.在3.3GHz~3.6GHz范围内其输出功率不低于39.2dBm,增益不低于12dB,功率附加效率为62.6%~69%;在环境温度为21℃下,运用红外温度扫描仪进行测试,该款射频功率放大器最高温度达到90.0℃,测试结果与仿真分析结果相近.论文的研究为未来射频功率放大器的设计及制作提供了重要指导.     

Highly integrated 60 GHz transmitter and receiver MMICs in a GaAs pHEMT technology

Highly integrated transmitter and receiver MMICs have been designed in a commercial 0.15 /spl mu/m, 88 GHz f/sub T//183 GHz f/sub MAX/ GaAs pHEMT MMIC process and characterized on both chip and system level. These chips show the highest level of integration yet presented in the 60 GHz band and are true multipurpose front-end designs. The system operates with an LO signal in the range 7-8 GHz. This LO signal is multiplied in an integrated multiply-by-eight (X8) LO chain, resulting in an IF center frequency of 2.5 GHz. Although the chips are inherently multipurpose designs, they are especially suitable for high-speed wireless data transmission due to their very broadband IF characteristics. The single-chip transmitter MMIC consists of a balanced resistive mixer with an integrated ultra-wideband IF balun, a three-stage power amplifier, and the X8 LO chain. The X8 is a multifunction design by itself consisting of a quadrupler, a feedback amplifier, a doubler, and a buffer amplifier. The transmitter chip delivers 3.7/spl plusmn/1.5 dBm over the RF frequency range of 54-61 GHz with a peak output power of 5.2 dBm at 57 GHz. The single-chip receiver MMIC contains a three-stage low-noise amplifier, an image reject mixer with an integrated ultra-wideband IF hybrid and the same X8 as used in the transmitter chip. The receiver chip has 7.1/spl plusmn/1.5 dB gain between 55 and 63 GHz, more than 20 dB of image rejection ratio between 59.5 and 64.5 GHz, 10.5 dB of noise figure, and -11 dBm of input-referred third-order intercept point (IIP3).     

A monolithic micropower command receiver

The use of battery-operated chronically implanted telemetry systems in biomedical instrumentation is growing rapidly. In many cases the flexibility and operating lifetime of these systems is severely limited by the capacity of the power source. Describes the theory of operation, design, fabrication, technology and performance of a micropower command receiver that can extend the operating lifetime of an implanted telemetry system to the shelf life of its battery by disconnecting the power source when the system is not in use. The command receiver consists of an RF amplifier, and AM detector, and an audio amplifier. It has a sensitivity of better than 100 /spl mu/V and a total power dissipation of less than 15 /spl mu/W. It operates from a single 1.35-V mercury cell and is fabricated entirely on a single silicon chip. The only necessary off-the-chip components are the antenna and the battery.     

一种用于GPS接收机的低噪声放大器

针对GPS接收机低功耗、低噪声、高增益的要求,采用功率限制下噪声匹配技术、阻抗匹配技术和电源复用技术,设计了一款可应用于GPS接收机的单端输入差分输出低噪声放大器,减少了巴伦损耗。采用SMIC 0.13 SymbolmAm CMOS RF工艺和全定制集成电路设计方法,工作频率为1575 GHz,对电路进行版图后仿真。仿真结果表明,该低噪声放大器在1.2 V电源电压下,功耗为4.8 mW,增益为22.65 dB,噪声系数为1.388 dB。