# Transmission lines and electromagnetic waves

By Prof. Ananth Krishnan   |   IIT Madras
Learners enrolled: 1359
Bridge course to practical aspects of engineering electromagnetics for entering Graduate students and senior undergraduate students. The course will involve hands on programming to visualize most aspects of electromagnetics and transmission lines.

INTENDED A
UDIENCE : M.Tech. 1st years and B.Tech. 3rd or 4th years
PREREQ
UISITES : Nil
INDUSTRY
SUPPORT : BEL, ISRO, Comsol, HFSS
Summary
 Course Status : Completed Course Type : Core Duration : 12 weeks Category : Electrical, Electronics and Communications Engineering Photonics Credit Points : 3 Level : Postgraduate Start Date : 24 Jan 2022 End Date : 15 Apr 2022 Enrollment Ends : 07 Feb 2022 Exam Date : 24 Apr 2022 IST

Note: This exam date is subjected to change based on seat availability. You can check final exam date on your hall ticket.

### Course layout

Week 1 : Circuit model of a lossless transmission line
a) Introducing space coordinate in circuit diagram
b) The notion of delay in a lossless interconnect
d) The spatial derivative in equations for V and I
e) Telegraphers equations
f) Decoupling to wave equation
g) Meaning of the analytical solution to wave equation - The existence of voltage and current waves

Week 2 : Programmatic approach to solving partial differential equations - Finite differences
a) Taylor’s series approximation to first and second derivatives
b) Partial derivatives
c) Octave/Matlab based solution to voltage in a capacitor (Laplace solver)
d) Meaning of Dirichlet and Neumann boundary conditions and the voltage in parallel plate capacitor
e) Octave/Matlab to solve wave equation
f) Octave/Matlab to solve Telegrapher’s equations
g) Implication of short circuit or open circuit in a transmission line
h) The reflection coefficient
i) Time domain reflectometry
j) Time of flight based inferences
k) Bounce diagrams and time evolution of voltage

Week 3 : Non-idealities in the transmission line circuit model
a) Resistor and conductor in circuit equivalent
b) Steady state AC in transmission line
c) The propagation constant and characteristic impedance
d) Impedance in the transmission line
e) Standing Wave and Voltage Standing Wave Ratio
f) Power in transmission line

Week 4 : Impedance matching
a) Quarter wavelength transformer
b) Stub based matching

Week 5 : Equivalence of Maxwell’s equations and telegraphers equations

Week 6 : Programmatic solutions to Maxwell’s equations using Octave/Matlab

Week 7 : Power and Poynting vector

Week 8 : Losses in propagation and propagation constant, Polarization (the only difference from transmission lines)
a) Linear, circular, elliptical

Week 9 : Reflection and transmission at interfaces (analogous to transmission lines)
a) Reflection coefficient and transmission coefficient
b) Standing waves
Effect of reflection and transmission on Polarization (different from transmission lines)

Week 10 : Dielectric-Dielectric and Dielectric-Metal interfaces, Fresnel coefficients,Brewsters angle,Total internal reflection

Week 11 : Parallel plate and rectangular waveguides, Modes of parallel plate and rectangular waveguides

Week 12 : The cut-off frequency, Dispersion

### Books and references

R.K. Shevgaonkar, Electromagnetic waves

### Prof. Ananth Krishnan

Ananth Krishnan is a faculty member at the department of electrical engineering in IIT-Madras. His specialization is Photonics and specifically Plasmonics

### Course certificate

The course is free to enroll and learn from. But if you want a certificate, you have to register and write the proctored exam conducted by us in person at any of the designated exam centres.
The exam is optional for a fee of Rs 1000/- (Rupees one thousand only).
Date and Time of Exams: 24 April 2022 Morning session 9am to 12 noon; Afternoon Session 2pm to 5pm.
Registration url: Announcements will be made when the registration form is open for registrations.
The online registration form has to be filled and the certification exam fee needs to be paid. More details will be made available when the exam registration form is published. If there are any changes, it will be mentioned then.
Please check the form for more details on the cities where the exams will be held, the conditions you agree to when you fill the form etc.

CRITERIA TO GET A CERTIFICATE

Average assignment score = 25% of average of best 8 assignments out of the total 12 assignments given in the course.
Exam score = 75% of the proctored certification exam score out of 100

Final score = Average assignment score + Exam score

YOU WILL BE ELIGIBLE FOR A CERTIFICATE ONLY IF AVERAGE ASSIGNMENT SCORE >=10/25 AND EXAM SCORE >= 30/75. If one of the 2 criteria is not met, you will not get the certificate even if the Final score >= 40/100.

Certificate will have your name, photograph and the score in the final exam with the breakup.It will have the logos of NPTEL and IIT Madras .It will be e-verifiable at nptel.ac.in/noc.

Only the e-certificate will be made available. Hard copies will not be dispatched.

Once again, thanks for your interest in our online courses and certification. Happy learning.

- NPTEL team