Study And Design Of Radio-frequency Front-end Of 2.4GHz Receiver

The rapid development of wireless communication makes the frequency resource becoming scarcer and scarcer. The special function of RF front-end in the wireless communication transceiver makes it be the key and difficult in the research of wireless communication domain all around the world. According to the requirement of wireless QPSK modulation transmission system of the project"multifunctional and universal signal sources, this thesis studies and discusses the designing method of the RF front-end of the receiver as well as its main modules at 2.4GHz ISM band. Main works and innovation of this thesis include:Firstly, this thesis presents the performance parameters of RF receiver, and analyses and compares the usual structures of RF receiver. Then, according to the actual requirements of the project, this thesis presents the adoptive RF receiver structure of 2.4GHz wireless communication system, and analyses the performance parameters of this structure.Secondly, it is emphasized on the RF filters. Based on the analyzing of the designing theory and method for the RF micostrip band-pass filters, several usual micostrip band-pass filters are simulated and analyzed. Then, a compact hairpin microstrip bandpass filter centered at 2.45GHz is designed, simulated and optimized innovatively based on SIR, at last, manufactured the hardware circuit. The measurement result demonstrates that it is in agreement with the simulation result, and the designed filter is of small dimension with ideal performance.Finally, a LNA based on transistor and a passive single balanced mixer based on frequency diode is designed and simulated using software. According to system requirements, this thesis makes optimization of simulation to the modules circuits and analyzes the performance parameters again and again. Finally, the modules of a 2.4GHz communication system RF front-end which can satisfy the requirement of the project are designed. At last, the hardware circuits of LNA and mixer based on MMIC are manufactured, measured and debugged, and the performance measurement results and the results analysis satisfies the requirement of the project and validates the feasibility of each designing module.