# Deformation of EM wave signals

Deformation of EM wave signals
14 August 2012

Electromagnetic wave carries signals emitted by antenna into space. The EM field of a wave is mathematically defined by the EM wave equation whose monochromatic solution is the equation (1). A signal is a time varying EM field that can be expressed by Fourier series which is the sum of monochromatic wave functions, that is, a sum of equation (1) of different amplitudes and wave lengths.

We notice that the amplitude and phase of the equation (1) vary with distance and frequency, that is, monochromatic EM waves of different frequencies evolve differently in space. In consequence, the form of the Fourier series is distorted, the traveling signal is deformed. What is the extent of the deformation of EM signal in space?