5. Noise, Nonlinearity and Time Variance

In this chapter we deal with the topics of Noise, Nonlinearity and Time Variance. We begin with a presentation of the various noise sources of importance to a receiver, in particular, Thermal Noise, and its definition, quantification and voltage and current circuit models; and Shot noise and its quantification. Then, we take on the topic of Signal-to-Noise Ratio, including, available noise power, Noise Figure, Noise Temperature, and Noise Figure of Cascaded Linear Networks. This is followed by the topic of Mixer Noise Figure, in particular, Single-Sideband and Double-Sideband. We conclude this part with a discussion of the calculation of the noise at baseband for a system consisting of a cascade of building blocks. Then, we address the topics of Nonlinearity and Time Variance. In particular, we review effects of nonlinearity, namely, Gain Compression and Intermodulation, and then address the topics of Cascaded nonlinear stages, Second-order intercept point, Intermodulation Distortion Formulas, Cascade Second-order input intercept point (IIP2), Twotone IIP2, One-tone IIP2, Time-varying-envelope signal IlP2, Thirdorder intercept point (IIP3), Cascaded third-order input intercept point (IlP3), and Two-tone IlP3.