introduction to antennas - familiarization
DESCRIPTION
This presentation familiarizes the student with some commonly used antennas using imagesTRANSCRIPT
1Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 1
Introduction to Antennas:
Familiarization
2Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 2
Definition of Antenna (or Aerial)
A means of radiating or receiving radio
waves
An interface between a circuit and free
space
A transducer which converts time-varying
currents to photons and vice-versa
3Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 3
R F Bands Microwave BandsName Frequency Name Frequency
ELF 3 – 30 Hz L 1 – 2 GHz
SLF 30 – 300 Hz S 2 – 4 GHz
ULF 300 – 3 KHz C 4 – 8 GHz
VLF 3 – 30 KHz X 8 – 12 GHz
LF 30 – 300 KHz KU 12 – 18 GHz
MF 300 K – 3 MHz K 18 – 26 GHz
HF 3 – 30 MHz KA 26 – 40 GHz
VHF 30 – 300 MHz V 40 – 75 GHz
UHF 300 M – 3 GHz W 75 –100 GHz
SHF 3 – 30 GHz
EHF 30 – 300 GHz
Frequency Bands in EM Spectrum
4Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 4
Introduction to Antennas
Through Images
Frequency -vs- Wavelength; Photon Energy
5Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 5
6Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 6
Some Typical Antennas
7Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 7
Some Typical Antennas
8Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 8
Some Typical Antennas
9Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 9
Some Typical Antennas
10Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 10
Radomes
11Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 11
Ship-borne Antennas
12Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 12
Aircraft-borne Antennas
13Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 13
Aircraft-borne Antennas
14Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 14
Antennas on a Cruise-Missile(not marked)
15Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 15
Satellite-borne Antennas
16Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 16
The Pioneers in Antennas
JC Maxwell H R Hertz
JC Bose
G Marconi
17Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 17
First Trans-Atlantic Transmission
18Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 18
Marconi’s Transmitting Station (Poldhu)
19Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 19
Plaque Commemorating
Poldhu Transmitting Station
20Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 20
Prof. HidetsuguYagi
21Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 21
Prof. John D. Kraus
22Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 22
Antenna (BIG EAR) built by Prof. John D. Kraus and his students
23Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 23
Microstrip Antennas
24Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 24
Microstrip Antennas
25Presented by APN Rao, Dept ECE, GRIET, Hyderabad. Jul 2011 25
History of Development of Antennas
1864 - Existence of EM waves Predicted (JC Maxwell)
1886 – EM waves generated and detected (HR Hertz)
1901 – First Trans-atlantic wireless communication (G Marconi)
Prior to WW II – Wire antennas (below UHF range)
During WW II – Microwave antennas, power sources and other components
Following WW II – Array, Broadband & MicrostripAntennas
Later part of XX century – Advanced numerical methods and computational softwares, Smart antennas