1.1 Plane wave in a free space
A plane wave is the simplest form of the Maxwell’s equations solution. Its name refers to the shape of a wave front (constant phase surfaces, perpendicular to the direction of propagation) of a propagating wave:
Fig 1 Plane wave in a free space.
The basic parameters of a plane wave are: wavelength l, frequency f, and magnitude A. Wavelength is related to frequency and propagation speed (thus also the parameters of the medium in which wave propagates) according to the following formula:
where:
e - medium permittivity
m - medium permeability
There are four main properties of a plane wave:
1. Propagation speed - depends on medium parameters:
where
is a speed of light in vacuum, μr and εr stand respectively for the relative permeability and permittivity of a medium in which the wave propagates.
2. Electric and magnetic fields are perpendicular to the direction of propagation:
and 
3. Electric and magnetic fields are perpendicular to each other:
4. Wave impedance is equal to intrinsic impedance of the medium:
The above given formulae apply to a plane wave propagating in a lossless medium. When considering a plane wave in a lossy medium a general formula for sinusoidal plane wave is given with a complex notation as follows:
where 
stands for a complex amplitude, w is a pulsation, t – time, 
– radius vector and g – propagation constant, given with
where b is a phase constant and a an attenuation coefficient.
The objectives of this paragraph are:
· Study of the basic properties of a plane wave
· Observations of a wavelength change as a frequency function
· Observations of field envelope changes as a function of medium lossess
For the tutorials the basic ppw1.QWpro model and its modifications will be used. The description of how to create such model step by step can be found in a separate document.