0.18¦Ìm Silicon-based Rf Cmos Technology 5.8ghz Mixer Design

In the past years, the ever-increasing demand for both information and mobility calls for the combination of computer networks and the wireless capability. A number of systems have emerged to meet the requirements of wireless access networks . Among them a promising candidate is the IEEE 802.11a, i.e., 5.8 GHz wireless local area network (WLAN).The radio frequency integrated circuit is the indispensable key circuit in the wireless communication field, it is a main bottleneck of wireless communication. In recent years, with wireless communication capacity and promotion of speed of system, system's performance to RFIC put forward high request. At the same time, in order to meet the request of high dependability and low cost after the commercialization, the realization of CMOS RFIC on the single silicon chip become a focus that people is studying.The noise is a very important problem needing consideration while designing the mixer circuit. This text introduces the definition, formation mechanism and source of the noise, and provide the step of calculating noise of the mixer.Then it introduces basic principle of mixer which is applied in wireless communication, and the basic structure of mixer. The merits and defects of all kind of mixer are also discussed.Later, the article provides a mixer circuit design, which is applied by radio frequency transmitter of WLAN of 5.8GHz frequency band, including intact circuit structure, layout and simulation. The mixer, regarding improved Gilbert unit as the core, is realized by 0.18μm CMOS process.When the power supply is 1 V, the circuit works at 5.8GHz and achieves 12dB gain, 10dB noise figure (NF) and -12dBm 1dB-compression-point. the simulation result of the circuit can achieve the designing requirement. At end, the thesis summarizes all the modulator circuit design, and has put forward the improvement scheme and emphasis and direction of the following work.