REV4- Antenna Systems Part 3

-Grounded Quarter Wavelength antenna
-Vertical Monopole
-A practical antenna and a quarter-wave antenna which combines with its image to act as an exactly the same manner as the doublet or a dipole, with the radiator vertical to the ground surface. It has vertical polarization and specifically use for ground wave propagation.

Radiation pattern: Omnidirectional (in horizontal place)
Feed impedance: 37 ohms

• a. Marconi Antenna

• b. Folded Dipole

• c. Horn Antenna

• d. Parabolic Antenna

It is a single antenna consisting of two elements. The first is fed directly while the second is coupled inductively at the ends.

Radiation pattern: Bidirectional
Feed impedance: 292 ohms

Z = 73n7

• a. Marconi Antenna

• b. Folded Dipole

• c. Horn Antenna

• d. Parabolic Antenna

A flared waveguide will become a horn antenna. It has excellent gain and directivity.

G= 75dedM

• a. Parabolic Antenna

• b. Horn Antenna

• c. Helical Antenna

• d. Marconi Antenna

It is a form of a dish antenna with a reflecting surface that is a geometric paraboloid. It has a focal point where rays arriving parallel to the antenna axis converge.

• a. Parabolic Antenna

• b. Rhombic Antenna

• c. Helical Antenna

• d. Folded Dipole

An antenna that produces circularly polarized waves. The gain of a helical antenna is proportional to the number of turns can be several greater than the dipole.

• a. Helical Antenna

• b. Rhombic Antenna

• c. Parabolic Antenna

• d. Marconi Antenna

is a phenomenon whereby the polarization plane of radio waves rotates due to magnetic flux lines and electrons in the ionosphere.

• a. Faraday notation

• b. Faraday rotation

• c. Hertz notation

• d. Hertz rotation

-This refers to a non-resonant
horizontal antenna having four conductors forming a diamond or rhombus; usually fed at one apex and terminated with a resistance or impedance at the opposite apex.
-Non-resonant antenna used for long distance sky wave transmission or reception of horizontally polarized waves over distances from 200 to over 3000 miles at frequencies from 4 to
22 MHz.

• a. Rhombic Antenna

• b. Resonant Antenna

• c. Turnstile Antenna

• d. Pyramidal Antenna

-Standing waves exist, caused by the presence of both a reflected traveling wave and the forward wave.

-Antenna whose length is a multiple of
λ/4's

• a. Marconi Antenna

• b. Resonant Antenna

• c. Helical Antenna

• d. Turnstile Antenna

-This refers to an antenna that is formed by placing two dipoles at right angles to each other; 90° out of phase. The radiation pattern is the sum of the radiation patterns from the two dipoles, which produces nearly omnidirectional pattern.

G = 1.15

• a. Turnstile Antenna

• b. Resonant Antenna

• c. Pyramidial Antenna

• d. Lens Antenna

-a type of log periodic antenna

-It looks and works in much the same way as a standard log periodic antenna, with one big difference: the two halves of the transmission line are separated and positioned as a V, so each half of the transmission line is in effect a single wire transmission line.

• a. Turnstile Antenna

• b. Marconi Antenna

• c. Pyramidal Antenna

• d. Lens Antenna