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