Question

To transmit signals in the range 30 – 300 MHz space wave propagation is used

1. What is meant by space wave propagation? 

2. Why it is called Line of Sight (LOS)?

3. Derive an expression for area covered by a signal if height of antenna is h

Answer 1

1. In space wave propagation, wave travels in straight line from transmitting antenna to the receiving antenna. 

2. Because the receiving antenna and transmitting antenna should be in line of sight of wave. 

3. Range of signal from the antenna d = \(\sqrt{2Rh}\)

∴ Area A = πd² = π = \((\sqrt{2Rh})^2\)

A = π 2Rh.