ABSTRACT
In the previous chapters, we have been dealing mostly with monochromatic fields. Whenever it was necessary to account for finite spectral width (for instance, to introduce concepts like group velocity and dispersion, in Chapter 5), we considered only functions whose behavior was fully deterministic, both in time and in space. On the other hand, when we mentioned briefly in Chapter 12 that receiving antennas inevitably pick up noise, we went all the way to the other extreme, assuming implicitly that we were then dealing with completely random variables.
