Research And Design Of Key Module Circuit Of UWB Receiver Front-end

With the rapid development of wireless communication systems,a variety of wireless communication standards and protocols have been set in the last two decades,which puts forward higher requirements for the compatibility of wireless communication equipment,and one of the most important aspects is the working bandwidth.The increase of channel bandwidth can not only improve data transmission rates,but also make wireless communication devices compatible with more communication standards and communication protocols.In addition,ultra-wideband(UWB)technology also has the advantages of high spatial resolution,small multipath fading,strong anti-interference ability,and low power consumption.Therefore,UWB technology has become an important development directions for the future development of wireless communication equipment.As the key part of signal reception,the receiver front-end plays a vital role in the wireless communication system.This paper focuses on the design and improve of the UWB LNA and UWB Mixer,which are the key modules in the front-end of UWB receiver.The details are as follows:Firstly,this paper presents an UWB LNA operating in the C-Ku band,which solves the problem that the bandwidth and gain restrict each other caused by the load capacitance,and achieves good performance under the condition of large bandwidth.The LNA is designed with a two-stage amplifier circuit and an output buffer circuit.In the design process,the RLC series feedback network is applied.By adding a new zero to alleviate the high frequency performance attenuation caused by the poles.At the same time,the output impedance of the first-stage amplifier circuit and the input impedance of the second-stage amplifier circuit are conjugate matched by using a T-matching network to achieve the maximum power transmission.Finally,a source follower is used to form an output buffer to stabilize the output impedance.This design is based on the three-ampere photoelectric 0.25 um GaAs pHEMT process.The simulation results of layout show that the UWB LNA designed is in the band range of 6-18 GHz,with noise coefficient of 1.7-3.2dB,maximum gain of 15 dB,gain flatness of ±1dB,and input and output reflection loss lower than-10 dB.In order to meet the needs of the next generation of fully integrated receiver,a front-end module of UWB receiver working in K-Ka band was designed by using 45 nm CMOS SOI process.The module is composed of an UWB LNA and an UWB mixer.Adopt similar to the previous chapter to introduce new zero technology solves the load capacitance cause indicators such as the bandwidth and gain of the problem of constrained at the same time,also use transfer differential output single-ended input structure solved how to under the premise of not join such loss balance device to implement the single type of low noise amplifier and double balanced mixer connection problem,and solved by introducing a pair of differential inductance mixer nodes of parasitic capacitance on the circuit performance deterioration of the problem,at the same time under the condition of larger bandwidth achieved good performance.Simulation results of layout show that the UWB receiver front-end module has a conversion gain over26.7dB from 20 GHz to 40 GHz range with a deviation less than ±0.5dB,while a noise figure from 4.2 to 7dB.Both RF,LO and IF port reflection losses are less than-13 dB between 20 GHz to 40 GHz.In addition,the proposed receiver front-end module has a reverse isolation lower than-80 dB,and the isolation of port to port are all lower than-230 dB.