| The low noise amplifier (LNA) described in this paper is designed for2.45GHzradio frequency identification (RFID) system, based on this application background,the paper first describes the characteristics, the development history and theapplication trends in today of RFID technology.According to the system to thespecific circuit module considerations, the paper discusses the structure and operatingprinciple of the RFID system,including readers, tags, middleware and so on.In thecase of long-distance identification, the signal that the receiver sense is veryweak,which requires the receiver to provide a front-end amplifier under the conditionsof introducing the lowest possible noise.The design of LNA in this paper usingdegenerate source inductance structure which could obtain optimum noiseperformance under the conditions of power-constrained.Based on the detailed analysisof CMOS integrated components,noise sources and noise theory and LANstructure,this paper have completed the LNA schematic design,layout design andsimulation analysis.In the schematic design of the LNA,the input impedancematching,load network,the effective transconductance and gain, noise optimizationand linearity were discussed in detail.In the Layout design,we mainly consider thematching design, parasitic optimization design and reliability design;The simulationresults are as follows:At the frequency of2.45GHz,input reflection coefficient is-30dB,the gain is about18dB,noise is about1.6dB,1dB compression point is-6.68dBm,IIP3is4.66dBm.The design provides a very good linearity performanceand low-noise amplification which can meet the application requirements of2.45GHzRFID reader receiver. |
