| With the rapid development of Chinese national economy,the number of private cars has increased rapidly,which puts forward higher requirements for safe driving of cars.As a result,vehicle radar came into being and became a hot project for many companies and research institutes,and showed huge market demand.The low noise amplifier(LNA),as a key module of the vehicle radar receiving link,affects the performance of the entire receiver.Therefore,the design of LNA applied to vehicle radar has a very bright prospect.On the other hand,the fifth-generation mobile communication technology(5G),as an emerging technology,is gradually increasing the scale of base station construction and its application.5G not only has a wider working frequency band,but also has higher requirements for data transmission rates.The increase in efficiency is also conducive to reducing the power loss of the large-scale 5G base station in the future.This all puts forward more stringent requirements on the design of the power amplifier(PA).Substrate Intergrated Suspended Line(SISL)is a brand-new microwave transmission line.SISL has the advantages of low loss and high Q factor,which can reduce the noise figure of the low noise amplifier and increase the gain.Its simple packaging and low cost make the circuit manufacturing more convenient and available.The simulation and design of low noise amplifier based on SISL is the main work of this thesis.This article first investigates the research significance and the domestic and foreign development trends of low noise amplifiers working at 24 GHz and S-band power amplifiers.By comparing SISL with microstrip lines,rectangular waveguides and traditional suspension lines,the structure,electromagnetic characteristics and manufacture of SISL are introduced at length,and the performance advantages of SISL are summarized.Then it explains in detail the various indicators of the LNA,including noise figure,input and output matching,gain,linearity,as well as the efficiency indicators of the power amplifier,linearization technology,efficiency enhancement technology,and the classification of traditional power amplifiers.In the low-noise amplifier design,firstly,the formula is cited to prove that the advantages of SISL’s high quality factor can effectively reduce the noise figure.Then,the steps of determining indicators,selecting transistors and plates,schematic design,HFSS layout design,and co-simulation are carried out in sequence,and the design process of24 GHz and K-band low-noise amplifier based on SISL process is introduced.During the design process,because ADS could not accurately simulate the unique three-dimensional structure of SISL,a model was built in HFSS and the passive part of the FEM simulation circuit was built,and the SNP file was obtained and imported into ADS for joint simulation.The first design meets the requirements of various indicators in the 500 MHz bandwidth frequency band of 23.75-24.25 GHz.At the frequency of 24 GHz,S11=-28.36 d B,S22=-19.003 d B,the gain reaches 13.8d B,and the noise figure NF=0.815 d B.The second design encapsulates the finished chip based on SISL.After actual testing,the noise figure of the overall circuit is only 0.1-0.9 d B worse than the original chip.In addition,a S-band power amplifier based on board-level technology was designed.The operating frequency is 3.4GHz-3.8GHz.The matching circuit is built using Ga N HEMT tubes and the simulation is completed.The output power of the power amplifier circuit is 43.6d Bm-45.5d Bm,PAE Over 60%,the gain is greater than 11 dB. |
