Herz & marconi antenna

Herz & marconi antenna

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  HERTZ & MARCONI ANTENNA PRESENTEDBY: ANU THAPA 700408 ELECTRONICS & COMMUNICATION
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  HERTZ & MARCONI CONTENT HertzAntenna  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
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  HERTZ & MARCONI HERTZANTENNA 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
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  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
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  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 05
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  HERTZ & MARCONI RADIATIONPATTERN  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
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  HERTZ & MARCONI RADIATIONPATTERN 07 Fig. Radiation Pattern
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  HERTZ & MARCONI GAINDIRECTIVITY & 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 08
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  HERTZ & MARCONI APPLICATIONS: normally used for small applications and was used in set top TV antennas 09
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  HERTZ & MARCONI MARCONIANTENNA HISTORY AND INTRODUCTION  Invented by: Guglielmo Marconi in 1885 in Bologna  most common vertical antenna is known as Marconi antenna 10 Fig. Marconi Antenna
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  HERTZ & MARCONI RADIATIONPATTERN  radiation resistance is equal to 36.5 Ω 11Fig. Radiation Pattern Of Marconi Antenna
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  HERTZ & MARCONI DESIGNAND 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
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  HERTZ & MARCONI APPLICATION used in the radio broadcasting transmitters of high power 13
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  HERTZ & MARCONI COMPARISONBETWEEN HERZ AND MARCONI  Electrically, Marconi antenna operates as a Hertz antenna.  Physically It is only a one-quarter wavelength (1/4 l) long. 14
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  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 15
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  HERTZ & MARCONI 16