Question

State different types of wave propagates. Describe space wave propagation in brief.

Answer 1

Types of wave propogation:

(a) Ground wave propagation

(b) Sky wave propagation

(c) Space wave propogation: Used for a line of Sight communication also known as LoS. Space satellite communication and very high-frequency waves use this propagation method. It basically involves sending a signal in a straight line from the transmitter to the receiver. We must ensure that for very large distances, the height of the tower used for transmission is high enough to prevent waves from touching the earth curvature thus preventing attenuation and loss of signal strength.

There is a very important relationship for determining the height of the antennas and their corresponding distance of transmission given by:

Dm=(2RHt)-1/2 +(2RHr)-1/2

where Dm=distancbetweenen 2 antennas; R=Radius of earth=6400 km Ht=Height of transmission antenna; Hr=Height of receiver antenna. Also, very important to note is another important relation to determining the range of transmission(Dt) for a given antenna of height Ht is:

Dt=(2RHt)-1/2