Linearity Analysis of Traditional Single and Double Balanced Down Conversion Mixers

Abstract

More sophisticated designs of communicating devices are required with tremendous scaling in MOS. Mixers play a vital role in all radio transmitters and receivers. To improve the sensitivity of the receivers, the low noise amplifiers are designed with very high gain. Higher gain of amplifier saturates the preceding sections and forces them to operate in the nonlinear region. MOS based Single Balanced and Double Balanced mixers are the most common designs for down conversion mixer. The paper discusses the linearity issue for both the traditional mixers. Basic definition of linearity is explained and the mathematical analysis based on Taylor’s series expansion is carried out for single and double balanced mixers.

Keywords: Linearity, IIP3, mixer, mathematical analysis, amplifiers