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How does a half wave dipole work?
Construction & Working of Half-wave Dipole It is a normal dipole antenna, where the frequency of its operation is half of its wavelength. Hence, it is called as half-wave dipole antenna. The edge of the dipole has maximum voltage. The electrons here tend to move away from the dipole.
What is half wave dipole?
A half-wave antenna (referred to as a dipole, Hertz, or doublet) consists of two lengths of wire rod, or tubing, each 1/4 wavelength long at a certain frequency. It is the basic unit from which many complex antennas are constructed. For a dipole, the current is maximum at the center and minimum at the ends.
What is short dipole?
The Short dipole is the dipole antenna having the length of its wire shorter than the wavelength. A voltage source is connected at one end while a dipole shape is made, i.e., the lines are terminated at the other end. λ is the wavelength.
When to use a half wave or short dipole antenna?
Although the half wave dipole antenna is the most popular, the short dipole is also used, especially where space may be an issue, or where a non-resonant antenna is needed. As already mentioned the short dipole is a form of dipole antenna created by feeding a wire, typically in the centre with a signal.
What is the radiation pattern of a short dipole?
When the dipole is vertical, the horizontal radiation pattern is just a circle. Then in any vertical plane through the axis, the field strength varies according to sinθ. In fact the radiation pattern of a short dipole looks like that of a half wave dipole – the familiar figure of ‘8’ shape..
What kind of sine curve does short dipole follow?
Current distribution for the short dipole follows the same sinusoidal curve as used for all other forms of dipole. However as only the end section of the sine curve is applicable, this can be equated to a straight line without introducing any major errors.
How is the feed impedance of a short dipole antenna determined?
Both length measurements must be in the same units. The overall input feed impedance for the short dipole antenna is comprised of a number of different elements: the series inductance, the capacitance, radiation resistance, and the Ohmic resistance. These need to be combined vectorially to obtain the overall feed impedance.