Correct Answer - Option 2 : two circularly polarized components rotating in opposite directions
Polarization of a wave is defined as the time-varying behavior of the electric field strength vector at some fixed point in the space.
An electric field propagating in the z-direction can be split into orthogonal x and y components as:
\({E_x} = {E_x}\cos \left( {\omega t + {\phi _x}} \right){\vec a_x}\)
\({E_y} = {E_y}\cos \left( {\omega t + {\phi _y}} \right){\vec a_y}\)
The type of polarization depends upon the differences in phase and magnitude of x-direction and y-direction of the EM wave.
For a wave to be elliptically polarized, the filed must have two orthogonal components having different amplitudes, i.e.
Ex ≠ Ey
This can be seen as the superposition of two circular polarization possessing different magnitude and direction since for a circularly polarized wave, Ex = Ey
Polarization of wave:
- There are three main types of polarisation namely, linear polarisation, circular polarisation, and elliptical polarisation.
- The polarization of an antenna is based on the E-plane orientation of the electromagnetic energy radiated/received by the antenna.
- Most antennas are typically either linearly (horizontal and vertical), or circularly polarized.
- It is important to match the polarization of the RF antenna to that of the incoming signal, otherwise, there is a corresponding decrease in the level of the signal.
