ABSTRACT
Maxwell’s equations indicate that the time-varying electromagnetic (EM) field is a rotational solenoidal field in the source-free space (r = =0 0, J ). In other words, electric force lines and magnetic field lines are closed without any endpoints. The electric field and magnetic field cross-link and excite each other to generate EM waves, which are the main form for EM energy to propagate forward. According to the shape of the phase surface (also known as the wave front plane), waves are classified into plane waves, spherical waves, and cylindrical waves. Among them, a plane wave is the simplest one in structure. In a small region far away from the radiating source, the spherical wave may be approximated as a plane wave. All the field quantities are in a plane normal to the direction of their propagation. The other forms of EM waves are created by mixing plane waves. If the amplitude and direction of the planewave electric field are identical on the whole equiphase surface, it can be defined as a uniform plane wave. Thus, it is very important to comprehend and master the transmission characteristics and basic properties of plane waves1-5.
