Abstract
In this work, we designed a mixer for 5.2 GHz wireless LAN with a standard SiGe BiCMOS 0.35 μm process. Circuit Simulation is accomplished by using ADS (Advanced Design System). Firstly, the operation theory of a mixer and important considerations in designing a mixer for RF wireless LAN are described. Then, the mathematical theories of single balanced and double balanced mixer and their modeling are discussed. After that, small-signal model is applied to describe the operation of mixer. Mathematica was used to calculate the equations. From the equations mentioned above, we analyzed the key points that affecting the performance of the mixer and find out the best way to design the mixer. Finally, except for the emitter degeneration of Gilbert Cell mixer, we find two methods to improve the power consumption and other performance of an RF mixer.