Studies On Radio-frequency Front-end Of 2.4GHz Transceiver System And Realization Of Key Modules

The rapid development of wireless communication makes the resource of frequency is becoming scarcer day by day. The special function of RF front-end in the wireless communication transceiver makes it is the key and difficult research in domestic and foreign wireless communication domain. According to the requirement of wireless QPSK modulation transmission system of the project"multifunctional and universal signal sources", this paper discusses the designing method of RF front-end in the transceiver at 2.4GHz ISM band.Since that the RF modules need to deal with high frequency analog signals in a wide dynamic range, how to realize impedance match at such a high frequency band and satisfy the wide dynamic range are the difficulties of this paper. Through summarizing domestic and foreign RF front-end designing experience, and according to the requirements of actual system performance and parameters, this paper finally realizes the design of RF front-end key modules of 2.4GHz transceiver. Main works and innovation of this paper include:(1) Firstly, this paper analyses the usual structures of the transceiver, and presents the advantage, disadvantage and performance parameters of each structure. According to actual requirements of the project, this paper presents the adoptive structure of 2.4GHz wireless communication system, and analyses the performance parameters of this structure based on channel model.(2) Secondly, after analyzing the theory of each key module in the transceiver respectively, this part presents the performance parameters and designing method of each module. Then this paper designs and simulates each key module in the transceiver by using Advanced Design System 2005. These key modules include IF filter, up-mixer, local oscillator, RF filter, power amplifier, low–noise amplifier, down-mixer. According to system requirements, this paper makes the optimization of the simulated circuits and performance parameters again and again. Finally, we designed a 2.4GHz communication system RF front-end which can satisfy the requirement of the project. Based on the simulation results, this paper designs PCB of the key modules, debugs the circuits, makes performance test and data analysis, which satisfies the requirement of the project and validates the feasibility of each designing scheme.(3) Finally, according to the test results of each module, this paper analyses the error of the circuits, and brings forward some improvement methods for the error and points out the future works.