Contents
What is the radiation pattern of dipole antenna?
The radiation pattern of the half-wave dipole is maximum perpendicular to the conductor, falling to zero in the axial direction, thus implementing an omnidirectional antenna if installed vertically, or (more commonly) a weakly directional antenna if horizontal.
How does a fan dipole work?
The way in which the HF multi-band fan dipole operates is that each dipole presents a low impedance at the feed point at its resonant frequency. As the frequency moves away from the resonant frequency of one dipole, its impedance increases and it does not absorb power.
What is a fan dipole?
Full-Size Fan dipoles are multi dipoles that are fed with a common feed point. The full-size dipoles are spread out like a fan, hence the name Fan Dipole. A good example of a Full-Size Fan Dipole is a full-size 40- and a full-size 80-meter dipole on a common feed.
Is dipole antenna omnidirectional?
Commonly known as an omnidirectional antennas, all dipole antennas have a generalized radiation pattern. The dipole antenna is not a directive antenna, since its power is radiated 360 degrees around the antenna (one of the reasons for FCC power gain limitations).
Does a fan dipole need a balun?
Yes you do want to install a balun. It’ll keep the RF where you want it – on the dipole legs. The more unbalanced a dipole is the more you need a balun and a dipole in the attic is going to be very unbalanced given the coupling to ducting, wiring etc.
What is the radiation pattern of a dipole antenna?
Dipole antenna. The radiation pattern of half-wave (or most other) dipoles is maximum perpendicular to the conductor, falling to zero in the axial direction, thus implementing an omnidirectional antenna if installed vertically, or (more commonly) a weakly directional antenna if horizontal.
How does a HF Multi Band fan dipole work?
HF Multi-band Fan Dipole Antenna 1 Operation of HF multiband fan dipole. The way in which the HF multi-band fan dipole operates is that each dipole presents a low impedance at the feed point at its 2 Implementations of the fan dipole. 3 Determining the lengths of the fan dipole.
What can a fan dipole antenna be used for?
These fan or parallel dipole antennas provide multi-frequency or multi-band oepration that is used for a variety of commercial radio communications applications as well as for ham radio where they can allow operation on multiple bands using a single feeder.
What is the length of a fan dipole?
In the case of the fan dipole above, the length L1 is a quarter wavelength at the lowest frequency band, L2 the next one up, and finally L3 is a quarter wavelength at the highest band.