dipólussal

A dipólussal, often referred to as a dipole antenna, is one of the simplest and most fundamental types of antennas used in radio communication. It typically consists of two conductive elements, usually wires or rods, oriented end-to-end and separated by a small gap at their center. This gap is where the antenna is fed by a transmission line, introducing the radio frequency current.

The operation of a dipole antenna relies on the principle of electromagnetic radiation. When an alternating current is applied to the antenna elements, it creates oscillating electric and magnetic fields. These fields propagate outward from the antenna as radio waves. Conversely, when radio waves encounter a dipole antenna, they induce an alternating current in its elements.

The length of a dipole antenna is crucial to its performance. For optimal efficiency, the total length of the dipole is usually made to be approximately half the wavelength of the radio waves it is designed to transmit or receive. This is known as a half-wave dipole. Variations exist, such as the short dipole, where the length is significantly less than half a wavelength, and the full-wave dipole, which is one wavelength long.

Dipole antennas exhibit a directional radiation pattern. For a standard half-wave dipole, the radiation is strongest perpendicular to the antenna elements and weakest along the axis of the antenna. This characteristic makes them suitable for many applications, from amateur radio to broadcasting and television reception. Their simplicity, ease of construction, and predictable performance have made the dipole antenna a cornerstone of radio technology.