Question

Write a short note on surface wave propagation of electromagnetic waves.

Answer 1

Hint: We should know that surface wave propagation is a classification of electromagnetic wave propagation. We can call electromagnetic wave propagation as radio wave propagation also. It is the behavior of radio waves as they propagate from one point to another or into various parts of the atmosphere. Surface wave propagations are also known as ground wave propagation. We will also discuss advantages, disadvantages, and applications of surface waves.

Complete answer:
We know that surface wave propagation is a type of electromagnetic propagation in which waves propagate over the earth’s surface in low and medium frequencies. These waves are usually used for transmission between the surface of the earth and the ionosphere. They are a combination of a number of constituent waves.

These waves are called surface waves or ground waves because it is the sum of the waves that are reflected by the earth’s surface or any hills or mountains. These waves follow the curvature of earth, which enables them to cover beyond horizon. Beyond the horizon, they are blocked by the curvature of earth and the signals are produced by diffracted surface waves.

Advantages of surface wave propagation:

Surface waves bends around the corners or obstructions during propagation which makes them more efficient and also they are not affected by the changes in atmosphere.

Disadvantages of surface wave propagation:

(a) In surface wave propagation, waves with high frequency cannot be transmitted as their energy losses are higher due to absorption of energy in the earth’s atmosphere.
(b) This type of wave propagation is usually used to cover short ranges and it also involves attenuation of waves as they interact with the eddy current produced by the surface of earth.

Note:
We should know the applications of surface waves. They are used in one-way communication from the military to submerged submarines as they penetrate to significant depth into sea water. But their main purpose is broadcasting AM,FM and television.