Herz & marconi antenna

Electrically,
Marconi antenna operates as a Hertz antenna.


Physically
It is only a one-quarter wavelength (1/4 l) long.

1. HERTZ & MARCONI ANTENNA PRESENTED BY: ANU THAPA 700408 ELECTRONICS & COMMUNICATION

2. CONTENT Hertz Antenna History Construction Introduction Radiation Pattern Gain, Directivity & Polarization Application Marconi Antenna History & Introduction Radiation Pattern Design and antenna modeling Application Comparison Between Hertz and Marconi Reference 02

3. HERTZ ANTENNA HISTORY Professor Heinrich Hertz made the first radio transmission in 1886 in his laboratory of Karlsrhule University. first antenna, he invented has the shape shown in the figure: 03 Fig. Hertz Antenna

4. CONSTRUCTION dipole can be any length, but it most commonly is just under 1/2 wavelength long dipole has an input impedance that is purely resistive and lies between 30 and 80 ohm 04 Fig. Construction

5. Introduction dipole antenna, with ½ wavelength very small, compared to its wavelength that is about one-hundredths of the wavelength at its operating frequency radiation pattern of hertz antenna is not truly isotropic 05

6. Radiation pattern fat doughnut with the dipole piercing its central hole Gain is stronger in the direction of maximum radiation radiation from an isotropic radiator is in the same direction 06

7. RADIATION PATTERN 07 Fig. Radiation Pattern

8. GAIN Directivity & Polarization: G ain of the Hertz Antenna is 2.1dBs Directivity a Gain (i.e. the directivity increases as the gain increases) can also be vertically polarized. antenna is placed perpendicular, or vertically with respect to the Earth’s surface 08

9. Applications: normally used for small applications and was used in set top TV antennas 09

10. MARCONI ANTENNA HISTORY AND INTRODUCTION Invented by: Guglielmo Marconi in 1885 in Bologna most common vertical antenna is known as Marconi antenna 10 Fig. Marconi Antenna

11. RADIATION PATTERN radiation resistance is equal to 36.5 Ω 11 Fig. Radiation Pattern Of Marconi Antenna

12. Design and antenna modeling vertical wire with a length of 1/4 of the working wavelength length of the wire in meters is calculated as L = ( 71,25 / Frequency MHz ) 12

13. Application used in the radio broadcasting transmitters of high power 13

14. COMPARISON BETWEEN HERZ AND MARCONI Electrically, Marconi antenna operates as a Hertz antenna. Physically It is only a one-quarter wavelength (1/4 l) long. 14

15. REFERENCE www.rfcec.com_RFCEC_Section-3 - Fundamentals of RF Communication-Electronics_07 - ANTENNA_Antenna - Description of Antenna 03 Marconi (Vertical) (By Larry E. Gugle K4RFE ) https://www.scribd.com/doc/54010193/Hertz-Discone-Antenna-Report Visited Date : August 2, 2016 15

16. THANK YOU 16