Research On High Dynamic And High Linearity Monolithic Low Noise Amplifier

As a key component of the RF receiving front-end,the low noise amplifier(LNA)almost determines the noise performance of the receiver.Under the condition of limited spectrum resources,improving the linearity and dynamic range of the LNA is conducive to processing the high PAPR signal with higher capacity and faster rates,which meets people's growing demand for communication system performance.Based on the 0.15 um GaAs E-pHEMT process,this paper analyzes the device structure,model,and typical GaAs process technology firstly.Furthermore,noise theory and nonlinear theory are introduced form the device level and the circuit level,respectively.The design points of monolithic LNA are summarized.The S-band wideband LNA is designed and tested.The tape-out test is consistent with the design.In the frequency range of 2-4GHz,the small signal gain is 27 dB ± 0.5dB,and the noise figure is less than 0.65 dB.The output power of the LNA is limited,which the P-1 is about 8dBm and IMD3 is about 37 dBc with a 5dB back off from P-1.In order to further expand the dynamic range and improve the linearity of the LNA under small signal conditions.This paper proposes a method to increase the output power of the LNA by power synthesis.A 90 ° on-chip integrated balun is used in the inter-stage and output stage.The 90 ° balun has good port matching characteristics.It plays the role of power distribution and isolation of input and output stages in the inter-stage network,and it plays the role of power synthesis and output port matching in the output network.Combine the parallel negative feedback structure at the power stage to further optimize the linearity of the output stage,and finally complete the layout design and simulation of a highly dynamic and highly linear monolithic LNA.The layout EM simulation results show that the LNA has a small signal gain of 26 dB,a noise figure of 0.9dB,and a saturated output power of more than 22 dBm.In the range of 2GHz ± 50 MHz,and the IMD3 is greater than 76 dBc with a two-tone input signal with a-25 dBm interval of 10 MHz.