Research And Design Of LNA And MIXER

At present, the GPS applications developed rapidly, and have spread from a few of research institutes and military sector to the various civilian fields. The wide applications of GPS has changed the way of people work, improved work efficiency and brought huge economic benefits, it has broad application prospects. In sharp contrast to such a large demand, all GPS receiver chips and OEM boards almost rely on imports. The GPS chip manufacturers abroad supply a large number of chips to China, whereas they have set up various restrictions on the positioning accuracy, the height and the mobile speed, so Independent development of China's self-positioning system is of great strategic significance and the market prospects. Conducting a study on the GPS, using CMOS technology to achieve low-cost, highly integrated GPS receiver RF front-end chip and making it market-oriented is of great significance.This paper firstly introduces several structures of RF receiver in brief, analyses two important indicators impacting on the receiver performance, and give the cascade formula of multi-level system's noise and linearity. The low-IF architecture was chosen as the system architecture By comparing the advantages and disadvantages of the structure of several receivers' architecture. According to GPS receiver performance requirements, an analysis of system link budget, completion of the rational allocation of module performance parameters, and a system-level simulation on the system with ADS were done. Then the low-noise amplifier and the mixer are designed according to the performance parameters with the TSMC 0.18um process.In the design process of LNA and MIXER, the paper introduces their basic working principle and performance parameters, designs the circuit according to the performance requirement, analyzes the circuits' noise and linearity and does the simulations on them with the simulation tool of SpectreRF of Cadence. The simulation results meet the requirements.