The half-wave dipole, with two poles each about one-quarter the length of the signal, is a particularly common solution.
22.
Between these vertical feed cables were the antennas proper, eight half-wave dipoles strung between the vertical cables and spaced ?of a wavelength apart.
23.
The folded dipole is similar to the simple half-wave dipole but with the feedpoint impedance multiplied by 4, thus closely matching that 300 ? impedance.
24.
In this upper side of space, the emitted field has the same amplitude of the field radiated by a half-wave dipole fed with the same current.
25.
It mounted a large antenna consisting of two rows of four half-wave dipoles aligned horizontally, rotating on a shaft located at the top of the tower.
26.
In general radio engineering, the term " dipole ", if not further qualified, is taken to mean a center-fed half-wave dipole.
27.
As the current is the same, the radiation resistance ( real part of series impedance ) will be half of the series impedance of a half-wave dipole.
28.
Since a half wave dipole is used, its antenna ( \ mbox { 2.15 dBi } = 1.64 ) should also be taken into consideration,
29.
The combination of the director's position and shorter length has thus obtained a unidirectional rather than the bidirectional response of the driven ( half-wave dipole ) element alone.
30.
Purely real impedances are very easy to match, and conveniently the real impedance of a slightly-less-than-half-wave dipole is fairly close to 75 Ohms.
