Simple Ship Collision Avoidance Radar Receiver Design

The primary function of radar receiver is to select the weak high frequency signal received by the antenna from interfering and noise,and then transfer it to monitors or computer controlled radar terminals after amplifying and demodulating.From the point of low cost,simple circuit and easy realization,and to meet the system requirements and indices of the basic ship collision avoidance radar,the thesis presented the producing process of every unit circuits and overall circuits,mainly focused on the study of the function and structure of the low noise amplifier,frequency synthesizer and the intermediate frequency amplifier,the circuit of which were aslo ananlyzed and designed.Results showed that the design met the system requirements.Therefore the expected results had been achieved.Firstly,the main technical parameters of low-noise amplifier were analysized,and then,a LNA was designed according to the requirements of the system,at last,simulation result was shown by MWO.In this thesis a LNA with 30dB gain and less than 2dB noise figure was realized.By comparing the three realization methods of frequency synthesizer,the thesis adopted the PLL plan.After that,principle of PLL was expounded,and the loop structure was analyzed,based on which the dual-frequency synthesizer was designed and realized,experimental results were presented as well.In the design of the IF AGC amplifier,the thesis introduced the classification and operational principle of AGC.The practical operational block diagram and related circuits diagram were presented.This paper regarded RF3330 and MAX2015 as main chip, and particularly expounded the circuit of amplifier and detector.Tested results showed that the IF AGC amplifier had the characteristics of credible control.Takeing up small room,this IF amplifier was high integrated,and easy to debug.