Research On The Key Technique Of Beidou Radio-Front

In order to realize the Radio-Front for "Beidou" receiver,this paper analyses the RF structures at first and chooses supersonic style for "Beidou" receiver RF.Based on the real data of the system, the parameters of RF are calculated .After a thoroughly study on the thesis of microwave ,the thesis summarizes the way of designing Low Noise Amplifier (LNA). A design of a LNA based on ATF551-M4's S parameter at right DC bais using Advanced Design System (ADS)produced by Agilent is simulated.The graphs shows it has absolutely stability,low noise and low reflection coefficient,indicating the method adopted is right and efficient.The paper also studies the module of Phase Lock Loop(PLL) and on which mechanism it works,deriving a way of having a optimal bandwidth.The frequency synthesizer using Si4133-BM integrated circuit is designed after a good understanding of the its inner structure.The work involves the calculation of the inductor needed as well as the dividers' load.Especial emphasis is made on extended operation mode of RF output,the the electric circuit of it is showed at last.The thesis also introduces the mechanism of Gilbert mixer and MAX2680 produced by MAXIM is chosen as down-converter of the receiver ,the matchworks decided by ADS are displayed. At last a method is given to design a microwave band-pass filter based on Chebyshew low-pass filter using table and frequency changing.The frequency coefficient and length of microstrip as well as the characteristic impedance are given.The difference between it and real filter simulated by Ansoft Designer SV is little ,indicating it is a new way to design filter of high performance.