Analysis And Design Of Mixer In GPS Receiver

The Global Positioning System (GPS) has a wide range application in various areas such as topographicalsurvey, traffic control management, navigation and field exploration. As a result, the research and development of GPS receiver can help us to take advantage of GPS service and promote the development of navigation technology of our country.The modern integrated circuit has large scale integration and uses off-chip components as less as possible, so the zero-IF architecture and low-IF architecture are usually preferred in receiver ICs. The thesis compares these two architectures and chooses the low-IF architecture according to the spectrum of the GPS signal. Frequency plan of the GPS receiver and the front-end specifications are also given in this thesis.The thesis introduces the principle, the classification and the specification of mixers, compares different types of mixers and finally chooses the topology of Gilbert mixer according the system specification.The thesis analyzes the Gilbert mixer in detail and gives a complete design methodology in designing the Gilbert mixer. Some auxiliary circuits are also introduced to realize the rejection of image signal and the generation of the quadrature LO signals. The design essentials of analog and RF circuit layout are referred in this thesis, the layout of each block in the circuit are also given. The simulation result shows the mixer fulfills the requirement of the system specification.