ABSTRACT
It is important to understand the microwave signals from the point of view of the quantum mechanisms. This chapter addresses this issue from the conventional understanding of the nature of electromagnetic spectra of modern understanding based on quantum physics. In this view, the novel issue is proposed such as a microwave cavity. In addition, microwave generation is also addressed. Moreover, the Josephson junction concept is introduced to understand how the microwave photons are generated through microwave circuits, which is important for antenna designing. In addition, the Langevin equation is addressed to demonstrate how the microwave signal processing occurs as a transformation of the incoming wave into the reflected outgoing wave across one-mode and one-port configuration.
