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What is the purpose of using folded dipole in place of half-wave dipole?
Half-wave folded dipole antennas are used where optimum power transfer is needed and where large impedances are needed. This folded dipole is the main element in Yagi-Uda antenna.
How is a folded dipole antenna better than a half-wave dipole antenna show the input impedance of a folded dipole antenna is 292 Ω?
Explanation: The impedance of folded dipole is four times the impedance of the half dipole. So its impedance is higher than the half dipole. Since folded dipole is a balanced antenna we use a balanced feeder so Balun is used. It is a dipole antenna with two ends folded back and connected to each other forming a loop.
What are the benefits of a folded dipole antenna?
The folded dipole is claimed to offer increased bandwidth, and to closely match 300-ohm line. This is much like the double bazooka antenna, or coaxial dipole antenna.
How are dipoles used in the FM band?
Another common place one can see dipoles is as antennas for the FM band; these are folded dipoles. The tips of the antenna are folded back until they almost meet at the feedpoint, such that the antenna comprises one entire wavelength. This arrangement has a greater bandwidth than a standard half-wave dipole.
Why is the bandwidth of a folded dipole increased?
The increased bandwidth of a folded dipole is almost entirely due to the extra thickness. Two parallel elements behave as a thicker single element. There is a small contribution too from the combination of the reactances of the transmission-line mode and radiator-mode acting in opposite directions.
What are the variations in a folded dipole?
Variations in folded dipole SWR is less with changes in antenna length or frequency are less than in a regular coax fed dipole. False: SWR variations are essentially the same. A regular coaxial fed dipole varies from ~50 ohms to ~70 ohms or so over normal height ranges.