Research On If Filter In RFIC For Satellite Navigation

Continuous-time filters characterized of working continuously are widely used in communications, video signal processing, computer storage systems, electronic measurement, automatic control and so on, especially in the mixed signal circuits of digit and analog. Continuous-time filters structured with OTA-C are applied on a large scale in integrated circuits because they have good high frequency characteristic, electrically controlled ability, and compatibility with CMOS.This study discusses systematically the OTA-C analog integrated filters on the background of RNSS satellite navigation receiver. RNSS broadband satellite receiver IF filters, different from GPS receiver narrowband IF filters, are Broadband BP filters. The main objective of this study is to design RNSS IF broadband BP filters with less consumption. Main task is to make sure the performance of the receiver IF filters through researching OTA-C active filter and the IF signal required by RNSS receiver. Finally we design a broadband BP IF filter for RNSS navigation satellite receiver system withTMIC 0.18μm CMOS.Firstly we brief the significance of this study with the developments and states of integrated active filter, and the definition, application, classes of CMOS OTA-C and the OTA circuits used in this study. Then we illustrate several programs and examples with OTA-C structure fully integrated active filters and emphasize the example of fitting the satellite receiver wideband IF filters. ADS simulation result shows that the function and performance of OTA-C filters matched with the RNSS satellite receiver IF filter. Finally, we give several frequency tunings to resolve the frequency drift caused by the manufacturing, process changes, temperature drift and aging device.