plane wave

1. University of Diyala Dep. of communication
College of Engineering 4th year
MICROWAVE ENGINEERING
LECTURE 2: UNIFORM PLANE WAVE
By Lect. : Israa Hazem Ali

2. ElectromagneticWaveMotion
1. Propagationof uniformplanewavein a losslessdielectricmedia
( un dampeduniformplanewave)
For lossless

3. 2. propagationof planewavein lossmedia

4. Whena lossmediais a goodconductor

5. 3. Normalincidentofuniformplanewaveon planeboundaries

6. 4. Reflectionandtransmissioncoefficient

7. Example: An air plane flying over the surface of ocean, for which (σ=4 s/m, εr=81,
µr=1) the airplane transmits a signal at 1 MHz through a trailing long wire antenna.
Assume for simplification that this transmitted wave is in the form of uniform plane
wave with an electric field intensityn1000 v/m and is incident normal to the ocean
surface. If the submarine requires a minimum signal level of 10 µv/m for adequate
reception. Determine the maximum communication depth of the submarine?
Solution:-
1- For free space

8. 2.Sea water
σ≫wε the medium is good conductor

9. The electric field transmitted into the ocean will be :
Et max =7.34 v/m
x=0
This will be reduced in magnitude over a distance d as it propagate into the ocean by the
factor of
Et = 10 µv/m= 10 -5
v/m
x=d
7.43
4
4
7.4

10. The average power transmitted through 1 m2
area of the surface is :
=
z=0 z=d
2