1. The document discusses uniform plane waves, including their propagation in lossless and lossy dielectric media. It provides an example of calculating the maximum communication depth of a submarine receiving a signal transmitted by an airplane flying over the ocean surface. 2. Key aspects of the example are determining the ocean is a good conductor due to its high conductivity, calculating the electric field transmitted into the ocean, and using the reduction in field magnitude over distance to find the depth where the signal equals the submarine's minimum requirement. 3. By setting the transmitted electric field equal to the minimum level at a depth d and solving for d, the example determines the maximum communication depth for the submarine is 7.4 meters.

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