This Presentation contains introduction to microwave engg. useful for UG EC Engineering Students

1. Microwave Engineering
(2171001)

2. Outline
• Objective.
• Pre-requisites.
• Teaching Scheme and Course Contents.
• Introduction.
• Applications.
• Course Outcome.
• Reference Books

3. Objectives
• To provide the basic theory pertaining to
microwaves.
• To provide basic theory pertaining to microwave
devices and systems
• To examine some of its applications to modern
communication systems.

4. Pre-Requisites
• Electromagnetic Spectrum.
• Behavior of Circuit/System at Low frequency.
• Fundamental Knowledge of Electromagnetic
Theory.
• EM wave propagation.

5. Microwave ??????

6. Microwave Engineering
• Engineering and Design of communication/ Navigation
systems in microwave frequency range.
• Microwaves: Waves typically having frequencies
ranging between 300 MHz and 300 GHz. This range is
also called as microwave region in electromagnetic
spectrum.
• These frequencies include free-space wavelengths
between 1 m and 1 mm. (Millimetre Waves)

7. Microwave
Millimeter
Wave
RF
Electromagnetic Spectrum

8. The Difference !!
1 cm
f =10 kHz,  = c/f = 3 x 108/ 10 x 103 = 3000 m
Phase delay = (2 or 360) x Physical length/Wavelength
f =10 GHz,  = 3 x 108/ 10 x 109 = 3 cm
Electrical length =1 cm/3000 m = 3.3 x 10-6 , Phase delay = 0.0012
RF
Microwave
Electrical length = 0.33 , Phase delay = 118.8 !!!
1  360 
Electrically long - The phase of a voltage or current changes significantly
over the physical extent of the device
Electrical length = Physical length/Wavelength (expressed in )

9. The Difference !!
Wireline
Coaxial Cable
Waveguide Fiber
1
kHz
10
kHz
100
kHz
1
MHz
10
MHz
100
MHz
1
GHz
10
GHz
100
GHz
10
14
Hz
10
15
Hz
l << 
Conventional
Circuit Theory
l   l >> 
Microwave
Engineering
Optics
Transmission Line

10. Why are microwave frequencies are of interest?
• As we go higher in frequency, fractional bandwidth
increases.
• Another advantage in going to higher frequency is
reduced antenna size. To make portable wireless
communications possible, we must operate at a
frequency at which the required antenna size is
reasonable!
• Increased antenna Directivity and Gain

11. • let’s assume that we wish to transmit a number of 4 kHz wide voice
signals through a wireless link and we have two wireless systems to
chose from, one operating at 500 MHz and the second at 4 GHz, each
with a 10 % bandwidth around its center frequency.
• In theory, the 500 MHz system could carry:
• In theory, the 4 GHz system could carry:
Capacity increases !!!

12. Applications
Satellite Communication
Radar
Mobile Communication
Medical Imaging (MRI,CT Scan)

13. & Yes of Course !!
Microwaves
Industrial and Household Heating
Purposes

14. & Many More !!

15. Course Outcome
• At the end of this course, Student learn Fundamentals
of Microwave Engineering with reference to
applications.
• Identify the difference between Low and High
frequency system design.
• Learn basic microwave devices.
• Can apply his/her understanding in design of
microwave circuits and its applications.

16. Reference Books
• Microwave Engineering, David M.Pozar, Wiley India
3rd Edition.
• Microwave Devices And Circuits, Samuel Liao, PHI.
• Microwave and Radar Engineering, M. Kulkarni,
Umesh Publications.