Analysis And Design Of Key Module Of Receiver For 2.45GHz Semi-active Tag

In recent years,with the rapid development of wireless communications technology,the gradually improving of the application of high-performance wireless communication system requirements,and especially with the rise of intelligent networking and hardware industries,all these fields are constantly promoting the development of radio frequency identification(RFID)technology which has been widely used in logistics,identification,financial payment and medical fields.As applications have continued to expand,people's demand for RFID technology is also increasing.Semi-active tags are the compromise of radio systems,active and passive tags on power and to read and write distance.This paper is based on the research protocol ISO /IEC1800-4 semi-active tags receiver RF front-end based key modules,including a low noise amplifier and a down-conversion mixer.The paper introduces the basic theory and application of radio frequency identification technology,and analyzes the main advantages and disadvantages of the RF receiver system,focusing on the indicators for the 2.45 GHz receiver RF front-end of the two key modules of-LNA and Mixer for analysis,discussion and compromise,designed a fully differential low noise amplifier structure,at 1.8V operating voltage,current consumption is 7.8mA,S11 is-14.9dB,S21(voltage gain)of 17.5dB,noise figure 2.21 dB,input third-order intercept point is 2.21dBm;down-conversion mixer,improved the structure of the classic Gilbert and shared trans-conductance respectively orthogonal structure,current injection technology to increase the gain and reduce noise.Simulation results show that the paper design of the mixer at 1.8 V operating voltage,current consumption is 3.1 mA,a conversion gain of 17.18 dB,input 1dB compression point and third-order input intercept point-13.5dBm respectively,-3.23 dBm,In 2M IF noise figure is 14 dB.The low-noise amplifiers and mixers designed in this paper are used in UMC 0.18?m process.The paper carries out their corresponding circuit layout design.Performance indicators have reached the design requirements of the receiver system,and the low-noise amplifiers and mixers in this paper can be well applied to the semi-active tag receiver system.