0
Upcoming SlideShare
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Standard text messaging rates apply

# Introduction to Antennas and Radiating Systems

1,013

Published on

0 Likes
Statistics
Notes
• Full Name
Comment goes here.

Are you sure you want to Yes No
• Be the first to comment

• Be the first to like this

Views
Total Views
1,013
On Slideshare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
42
0
Likes
0
Embeds 0
No embeds

No notes for slide

### Transcript

• 1. Introduction to Antennas & Radiating Systems
Austin Peay State University
William Cooke
Department of Physics & Astronomy
J. Caleb Wherry
Department of Computer Science
• 2. Outline
2
Introduction
What is An Antenna?
Transmission Lines
Free Space
The Antenna
How An Antenna Works
Electric and Magnetic Fields
The /2 Short Dipole
Conclusion
• 3. Introduction
3
• 4. What is An Antenna?
4
Transmission Line/Guided Path
A transmission line is a path in which a current flows. This line can be a typical circuit, coaxial cable, or any other material with a well-defined, complex impedance.
Free Space
Free space is made up of fields and void of other matter. These fields carry energy in the form of waves which can travel freely throughout.
Antenna
An antenna is the interface between the above transmission lines and free space. It takes the current from the transmission lines and converts it to waves which get transmitted into free space, and vice versa.
• 5. How An Antenna Works
5
• 6. How An Antenna Works
6
• 7. How An Antenna Works
7
Image Source:http://en.wikipedia.org/wiki/Dipole
• 8. Field Patterns
8
• 9. Field Pattern Lobes
9
HPBW: half power beam width
• 10. Power Pattern
10
Main lobe axis
Main lobe
Back lobes
Minor lobes
• 11.
11
• 12.
12
Retarded Current distance z away from poles:
Integrating over all dz’s to get E & H components of far field:
z
dz
• 13.
13
We can then find the Power by integrating the above field over a large surface of the Poynting vector: