2. HERTZ & MARCONI
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
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3. HERTZ & MARCONI
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. HERTZ & MARCONI
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. HERTZ & MARCONI
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
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6. HERTZ & MARCONI
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
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8. HERTZ & MARCONI
GAIN DIRECTIVITY & POLARIZATION:
Gain 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
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10. HERTZ & MARCONI
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. HERTZ & MARCONI
RADIATION PATTERN
radiation resistance is equal to 36.5 Ω
11Fig. Radiation Pattern Of Marconi Antenna
12. HERTZ & MARCONI
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)
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14. HERTZ & MARCONI
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.
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15. HERTZ & MARCONI
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
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