Research Of 1-4GHz Wideband Low Niose Amplifier

As a key module of multi-band multi-standard RF front-end system,wideband low-noise amplifier is one of the hot topics in the research of next-generation wireless communication standard technology.Wideband low-noise amplifiers as the first-stage active circuit of the RF front-end system need its wide bandwidth and low noise figure,which is a difficult point in the design of wideband low noise amplifiers.This paper aims at the characteristics and requirements of wireless communication applications in 1-4GHz,and studies 1-4GHz wideband low-noise amplifiers from the aspects of device structure,equivalent noise model,bias circuit,wideband matching technology,and circuit implementation.Work and innovation are as follows:?1?For GaAs pHEMT device structure and equivalent noise model,the main factors that affect the noise performance of GaAs pHEMT are analyzed.Combining with simulation,the bias of the GaAs pHEMT operating under minimum noise conditions is determined.?2?A self-bias wideband low-noise amplifier based on resistor divider bias circuit and parallel resistor negative feedback circuit is proposed.Based on the basic theory of RF circuit,the bandwidth,gain and noise performance of the self-bias wideband low noise amplifier are analyzed.In combination with simulation,the parameters of the self-biased wideband low noise amplifier were determined.?3?Based on the theory of noise matching and impedance matching,a wideband matching circuit is proposed to perform impedance matching on a self-bias wideband low noise amplifier.The wideband matching circuit allows the wideband low noise amplifier to take into account noise matching while performing impedance matching.?4?Based on the above analysis and design method,a 1-4GHz wideband low-noise amplifier was designed and implemented based on the 0.25um GaAs pHEMT process.The amplifier chip area is1.08mm×0.67mm,in the frequency range of 1-4GHz,power gain 25dB<S₂₁<26dB,input matching S₁₁<-10dB,output matching S₂₂<-9dB,reverse isolation S₁₂<-35dB,Noise figure NF<1.5dB,OP_1dB>6.5dBm.Based on the above work,the paper realizes the wideband matching and low noise figure of the low noise amplifier in the range of 1-4GHz,meets the requirements of multi-band and multi-standard RF front-end system and can be applied to the broadband communication system.