# Dipole Antenna: Dipole Aerial

### The dipole antenna or dipole aerial is one of the most fundamental antenna elements.

Dipole Antennas Include:
Dipole antenna basics     Current & voltage     Half wave dipole     Folded dipole     Short dipole     Doublet     Dipole length     Dipole feeds     Radiation pattern     Build HF ham dipole     Inverted V dipole     FM dipole design

The dipole antenna or dipole aerial is one of the most important forms of RF antenna. The dipole can be used on its own, or it can form part of a more complicated antenna array.

The dipole aerial or antenna is widely used on its own, but it is also incorporated into many other RF antenna designs where it forms the radiating or driven element for the overall antenna.

The dipole is relatively simple in its basic implementation and many of the basic calculations are quite straightforward. It is easy to design a basic dipole antenna that will operate on the HF, VHF and UHF sections of the radio frequency spectrum. That said, in depth mathematical analysis can require more complicated mathematical methods.

## Dipole antenna basics

The name 'di-pole' indicates that the dipole antenna consists of two poles or items – two conductive elements.

Current flows in these two conductive elements and the current and the associated voltage causes an electromagnetic wave or radio signal to be radiated outwards from the antenna.

As seen the antenna consists of a radiating element that is split into two separate conductor. These are normally on the same axis, and the dipole antenna is normally split in the centre. Power from a transmitter may be applied to be radiated, or power picked up by the antenna may be connected to a receiver. Normally the receiver or transmitter is connected to the dipole antenna via an intermediate feeder which enables the power to be transferred from one point to another.

The length of the radiating elements determine many of the properties of the dipole antenna: its feed impedance, centre operating frequency, whether it is a resonant antenna, etc.. As such the dipole length is an important aspect of the dipole antenna parameters.

## Dipole types

The most common form of the dipole antenna is the half wave dipole which gains its name because its length corresponds to an electrical half wavelength. However many other types of dipole antenna re also available.

• Half wave dipole antenna:   The half wave dipole antenna is the one that is most widely used . This type of dipole antenna is resonant, operating at a point where it is an electrical half wavelength long.