71045

Remarks on polarization

The polarisation of the wave is by convention defined by the motion of E. Both of the

two independent Solutions derived above are examples of linear polarization, one along

the x axis and one along the y axis. In each case E, H, and P form a right hand set of

mutually orthogonal vectors.

The generał solution for a uniform piane wave can be obtained by superposing any

combination, with arbitrary relative phases and amplitudes, of these two Solutions. The

result is that E then describes an elliptical path with arbitrary orientation and eccentricity.

Special cases include those of linear or circular polarization. In all cases the H vector

describes a path of the same shape, rotated 90 about the z axis in the right hand sense.

The ratio of the peak values of the electric field and magnetic field is a constant equal to

the characteristic impedance n defined above.

We notę that either sense (i.e. positive or negative) of circular polarization can be

synthesised by this procedurę.