System Noise-Figure Analysis for Modern Radio Receivers: Part 2, Y-Factor Noise-Factor Measurement

Abstract: This artice is the second half of a detailed discussion of noise factor for modern RF radio receivers. In Part 1 we discussed the general concept of noise figure and how it is used to convey noise-performance requirements by product definers and circuit designers. It is also used to predict the overall sensitivity of receiver systems. We also presented calculations for a cascaded receiver. In this continuation article we focus on the Y-factor measurement as it applies to mixers. We state which measurement is applicable to the cascade equations derived in Part 1. We also explore some variations of the measurement method the could be used to obtain an approximation to the SSB noise figure of a mixer.