【作者】 蒋金枝；

【导师】 颜永红；

【作者基本信息】 湖南大学 ， 微电子与固体电子学， 2007， 硕士

【摘要】 GPS(Global Position System)是全球定位系统的简称,目的是在全球范围内对地面或空中目标进行准确定位和监测。随着全球性空间定位信息应用的日益广泛,GPS提供的定位服务给人们的生活带来了巨大的变化和深远的影响。在GPS接收机中,由于不同的传输距离以及多路径衰减的效应,使得接收机收到的信号强度是不固定的,所以采用一个自动增益控制电路来将信号强度处理成一个固定的强度大小。文章的目的在于分析与设计一个应用于GPS卫星导航接收机的自动增益控制电路。首先介绍自动增益控制的原理,并对相关的电路设计进行了分析,接着针对GPS系统的设计要求,选取合适的结构进行设计。采用台积电TSMC 0.25μm CMOS工艺,实现一个具有指数控制曲线的可变增益放大器,高灵敏度高速的比较器,全差分结构的电荷泵,低输出电阻的缓冲器以及高精度的参考源电路。在2.5V的电源电压下,经过仿真验证,整个系统提供了54dB的动态范围,中频最大79dB的增益,频率范围为[2.5M,26M],功耗消耗为3.375mW;经过测试验证,整个系统的动态范围为54dB,中频最大70dB的增益,频率范围为[3.8M,25M],功耗消耗为5mW。更多还原

【Abstract】 Global Positioning System, called GPS for short, is used to accurately locate the object on the ground or in the air. As the extensive application of this locating technology, it brings huge changes in people’s daily life.In the GPS receiver, the signal strength level will be different due to the multi-path fading and different positions. The AGC is therefore used to adjust the received signal to a rated strength level.The target of this thesis is devoted to the analysis and designs of an automatic gain control circuit for GPS receiver. First we present the fundamental of AGC circuit and analyses correlative circuit design. Then we choose appropriate circuit to finish the design. We use TSMC 0.25μm CMOS process and design an exponential variable gain amplifier, a high resolution high speed comparator, a differential charge pump, a low output impedance buffer and a high resolution reference. Under 2.5V power supply, the simulation results show that our circuit provides 54dB dynamic range, maximal 79dB voltage gain in IF circuits, [2.5M,26M] bandwidth and 3.375mW power consumption; the test results show that our circuit provides 54dB dynamic range, maximal 70dB voltage gain in IF circuits, [3.8M,25M] bandwidth and 5mW power consumption.更多还原