The Design And Implement Of Key Modules Of RF Front-end Of Receiver

With the progress of microwave techniques,the receiver are developing fast recently. The RF front-end of receiver is a decisive factor producing an effect on important properties such as nonlinearity,noise factor,stability,sensitivity,gain.Therefore,research on the RF front-end of receiver have important practical meanings.Our project is to design and manufacture a RF front-end system of receiver.This thesis is focus on the three key modules which are radio frequency bandpass filter,low noise amplifier,PLL synthesizer.The fundamental theories and design approaches of the three key units in receiver RF front-end are introduced in this thesis. Moreover, the design examples and testing results of all three modules are given. First,the technical background of the project and main contents of this thesis are explained briefly. Second,major parameters and common organizations of receiver are recommendated. Third,the general theories about microstrip filter and the electromagnetic coupling characteristics and design methods of microstrip hairpin-resonator bandpass filter are suggested,the design process,simulation and testing outcomes of the hairpin filter module working on 900MHz is shown. Then,basic principles of balanced amplifier are analyzed in great detail,containing impedance matching, gain, stability and noise performance, the LNA adopted balanced structure is stated including its design procedures and testing results. Finally,frequency synthetic technique and the theory of PLL is elaborated, the circuit and testing results of the PLL synthesizer applying Si4133 is demonstrated.In the course of the design, we mainly considered passband platness and abrupt transition band of hairpin bandpass filter; taken gain,input/output VSWR,noise factor of LNA as optimization goals; checked frequency and power of output,phase noise of PLL synthesizer. All the testing results of the three modules meet design requirements within the range of allowable error.