This document discusses electromagnetic phenomena and transmission lines. It begins by describing how ancient and modern people have sought to understand phenomena like light, magnetism, and wireless communication. It then outlines Maxwell's equations, which relate electric and magnetic fields. Applications discussed include transmission lines, antennas, fiber optics, wireless communication, radar, and power systems. The document aims to develop an understanding of electromagnetic wave behavior and its various applications.

1. Electromagnetic wave and
Transmission line
Introduction

2. It is a subject Which has been fascinating human beings for many centuries.
• In ancient days people used to asked questions like
Why stars twinkling while planets do not?
why there is lightning?
Why magnetic needle deflect When it is putted in the environment?
How light reach the earth from the sun Where there is no medium in
between?

3. • In modern days people also try to investigate issues like
How radio stations operated?
How Tv reception occurred?
How do the mobile phone works?
Why Tv reception is good in some parts of the house and not at other places?
Why radio transmission in medium wave does not fluctuate with time
whereas short wave radio transmission does?
• All these phenomenon involves electromagnetism and almost all modern
gadgets works with the principle of electromagnetism.

4. EM phenomena
1. Low frequency high power
- Electrical machines, transformers, power generation, transmission and
distribution of electric energy.
2. High frequency low power
- Mobile communication, radar, satellite comm, optical fiber comm
• In this course we are going to develop the principles of electromagnetism
and investigate how time varying EM wave behaves.

5. Applications of Electromagnetic phenomena
• Transmission lines and HF circuits
• Antenna
• Satellite communication
• Fiber optic communication
• Cellular wireless communication
• Radar
• Electric power generation, transmission and distribution systems
• Renewable energy and energy conversion

6. In general EM phenomena is governed by the following four Maxwell’s
equations
Relate Electric and Magnetic fields generated by charge and
current distributions.

7. t
D
j
H
t
B
E
B
D

























0
 E = electric field
D = electric displacement
H = magnetic field
B = magnetic flux density
= charge density
j = current density
0 (permeability of free space) = 4 10-7
0 (permittivity of free space) = 8.854 10-12
c (speed of light) = 2.99792458 108 m/s

10. • Equivalent to Gauss’ Flux Theorem:
• The flux of electric field out of a closed region is proportional to the total electric charge Q
enclosed within the surface.
• A point charge q generates an electric field
0
0
0
1




 Q
dV
S
d
E
dV
E
E
V
S
V









 






0
2
0
3
0
4
4



q
r
dS
q
S
d
E
r
r
q
E
sphere
sphere










Area integral gives a measure of the net charge enclosed; divergence of the
electric field gives the density of the sources.
0




 E

Maxwell’s 1st Equation

11. Maxwell’s 2nd Equation
Gauss’ law for magnetism:
The net magnetic flux out of any closed surface is zero.
Surround a magnetic dipole with a closed surface. The
magnetic flux directed inward towards the south pole will
equal the flux outward from the north pole.
If there were a magnetic monopole source, this would give
a non-zero integral.
 




 0
0 S
d
B
B



Gauss’ law for magnetism is then a statement that There
are no magnetic monopoles
0


 B


12. Maxwell’s 3rd Equation
t
B
E








dt
d
S
d
B
dt
d
l
d
E
S
d
t
B
S
d
E
C S
S
S
















 









Equivalent to Faraday’s Law of Induction:
(for a fixed circuit C)
The electromotive force round a
circuit is proportional to the rate of
change of flux of magnetic
field, through the circuit.
 
 l
d
E



 

 S
d
B


N S
Faraday’s Law is the basis for electric
generators. It also forms the basis for
inductors and transformers.

13. t
E
c
j
B









2
0
1

Originates from Ampère’s (Circuital) Law :
Satisfied by the field for a steady line current (Biot-Savart Law,
1820):
I
S
d
j
S
d
B
l
d
B
C S S
   






 0
0 








14. Electromagnetic spectrum

15. Transmission media

17. Antenna
• Omnidirectional vs directional
• Resonant vs non resonant
• Wire type vs aperture type
• Size of antennas
• Smart antennas
• Array antenna

18. Satellite communication
* Large bandwidth L-band - (1-2GHz) K –band – (12-18GHz)
* Long distance S-band – (2-4GHz) ku-band – (18-27GHz)
* longer delay C-band – (4-8GHz) ka-band – (27-40GHz)
* Mobility x-band – (8-12GHz)

19. Fiber optic communication
• Propagation of light through optical fiber cable
• Total internal reflection
• Bending
• Light sources LASER , LED

20. Wireless and mobile communication
• Require various aspects of EM principles
• Cellular communication Base station , users, cell
• Multipath propagation (reflection, diffraction, scattering )
• Depending on the length of travel the wave will have either
constructive or destructive interference
• As the user moves the strength of the wave varies as a function of
time. This phenomena is called fading.
• Co channel interference

22. To design and install successful and feasible wireless link properly
developed propagation model is highly required. To develop
propagation model of the complex EM environment electromagnetic
principles are employed.

23. RADAR
• Detection and measurement
• Long range detection of targets
• Clutter
• Radar resolution

24. EMI/EMC
• How to avoid harmful interference
• Mitigation of EMI (filtering, grounding, shielding)
• Electromagnetic compatibility of devices and environment
• IOT and 5G
• Policy, standard, regulations, laws
• Monitoring and control