随着人们生活水平的不断提高和社会的不断发展，人们对于网络的依赖性越来越高，传统的局域网已经无法满足人们的需求，因此无线局域网便诞生了。无线局域网以其移动性强，组网使用灵活等特点，使得原来我们必须依靠必要的网络基础实施才能够使用网络的传统模式被打破。人们正逐渐将无线局域网看作是最常使用的接入互联网的方式，由于无线局域网低成本，高速率，易于部署，它已成为近年来发展迅速的领域。28225
近年来，硅工艺技术不断发展,其特征尺寸在不断减小, 尤其是深亚微米CMOS 工艺，它的MOSFET 特征频率能够达到50GHz 以上, 于是，利用CMOS 工艺来实现GHz 频段的电路被提上议程。CMOS 工艺以其特有的低成本, 高集成度的优势正逐渐成为世界上应用最广泛的工艺之一。
本次设计的低功耗高增益低噪声放大器欲采用0. 18μm CMOS工艺, 利用两级共源电路级联结构来实现高增益,至于电路的低功耗问题可以采用电流共享技术来使得电路达到相应理想的状态。射频接收机前端主要部分就是低噪声放大器，所以放大器的噪声能够越小越好。由于放大器所接收到的信号是较微弱信号，所以低噪声放大器必须是一个小信号线性放大器。
本论文首先介绍了接收机的基本结构和他的相关性能参数，然后提供了低噪声放大器的各项性能指标并简要说明了本次设计的输入阻抗匹配结构，结构上采用源极负反馈结构，通过利用噪声优化公式来选取不同参数的各项器件，一并在后面给出了相应的电路仿真结果。LNA电路测试结果为：在4.8GHz频率上增益为12dB，噪声为3.8dB，1dB压缩点对应输入功率为－6.2dBm。
关键词无线局域网(WLAN)，射频接收机(RF Receiver)，低噪声放大器(LNA)，噪声系数(NF)
Title    A low power and low noise high gain
amplifier based on CMOS process      
Abstract
Along with the continuous development of society and the continuous improvement of people's living standard, people depend on network more and more, traditional local area network has been unable to meet the people's demand on the network, so wireless local area network (WLAN) arises at the historic moment. Wireless local area network mobility, networking and flexible use, allows us to the original must be under the premise of network based implementation can use network was broken. Wireless LAN is becoming people most often use wireless access to the Internet, with its low cost, high speed, easy to deploy a rapid growth in recent years.
Silicon technology has been continuously developing in recent years, feature size decreases, the characteristics of frequency MOSFET of deep sub micron CMOS process has reached above 50 GHz, using CMOS technology GHz band circuit implementation possible. CMOS process has the advantages of low cost and high integration, which makes it the most widely used process in the world.
0. 18μ m CMOS technology was used in the design of low noise amplifier, two common source cascade circuit structure to achieve high gain, and the use of current sharing technology make the circuit work in low power consumption. This topic is responsible for the implementation of CMOS process to the design of IEEE 802.11a 5GHz WLAN wireless LAN receiver front-end circuit of a low power high gain low noise amplifier (LNA) based on. The low - noise amplifier is the main part of the RF receiver, so the noise is better. Since the signal received by the amplifier is a weak signal, a low noise amplifier must be a small signal linear amplifier.
This paper introduces the receiver's basic structure and performance parameters, introduces low noise amplifier performance index and the input impedance matching structure. This design uses is inductive source negative feedback structure, through noise optimization formula can be used to select the parameters of each device, and in the back of the circuit is given and the simulation results. LNA circuit testing results are: 4.8ghz frequency gain is 12 dB, the noise is 3.8dB, 1dB compression point corresponds to the input power for the 6.2dBm. 基于CMOS工艺的低功耗高增益低噪声放大器设计:http://www.751com.cn/tongxin/lunwen_22995.html