Design Of Mixer In Digital TV Tuner

With the rapid development of digital TV broadcast and personal communication in recent decades, people have realized the dream of communication anywhere and anytime, but the performances of transceiver is required to be more and more high at the same time such as weight, volume, power and price. In this situation, CMOS RF integrated circuit came to be the focus of designers. CMOS technology has the advantages of low cost and high integration and has exhibited more and more superiorities in high frequency circuits along with the progress of CMOS manufacturing technology. RF engineers achieve wireless front end so frequently by employing CMOS technology which has low cost and high yield.Digital TV tuner is one of the most important parts for TV receiving. It is the upgrade of analogy TV and helps analog TV receive and broadcast digital TV programs while possesses the application function of all broadcast and interactive multimedia. Mixer is the indispensable module in the digital TV tuner. The design technology always is researching a hotspot in RF IC, which is around the mixers' performance index. It needs to make compromise among gain, linearity, noise figure, isolation and power. As mixer is the second circuit of RF receiver, the gain and NF can be relaxed properly.In this dissertation, research background, research status and the main content is introduced at first, together with last several years' performance parameters of mixer which made one clear that what should be take into account when design a mixer. Then mixers' basic principle, main performance parameters and main frame are introduced. In the third chapter, a high performance mixer is designed by EDA tools of Mentor Graphics. Meanwhile, three wave band mixer of digital TV tuner are simulated and impendence matched well. In the end, the outlines of layout design in analog IC are introduced and then the layout for the mixer is presented based on SMIC 0.18μm CMOS technology.