1. Eng. Ibrahim N. Abu-Isbeih
Type of Wave
Propagation Modes of EM Waves:
Ground-Wave Propagation
Sky-Wave Propagation
Space (Line-of-Sight) Propagation
Eng. Ibrahim N. Abu-Isbeih

2. Propagation Modes of EM Waves
Three types:
Ground-Wave Propagation
Sky-Wave Propagation
Space (Line-of-Sight) Propagation
Eng. Ibrahim N. Abu-Isbeih

3. Eng. Ibrahim N. Abu-Isbeih
Radio Frequency Bands
Eng. Ibrahim N. Abu-Isbeih

4. 1- Ground Wave Propagation
Follows contour of the earth
Can propagate considerable distances
Frequencies up to 3 MHz
Example: AM radio broadcasting uses MF band
Eng. Ibrahim N. Abu-Isbeih

5. Eng. Ibrahim N. Abu-Isbeih
2- Sky Wave Propagation
At HF bands, the ground waves tend to be absorbed by the earth. The waves that reach ionosphere ( km above earth surface), are refracted and sent back to earth
Eng. Ibrahim N. Abu-Isbeih

6. 3- Space Wave Propagation
VHF Transmission
Waves follow more direct paths
LOS: Line-of-Sight Communication
Directional antennas can be used
Reflected wave interfere with the original signal
LOS path
Reflected Wave
Eng. Ibrahim N. Abu-Isbeih