bandenantennes

Bandenantennes, often translated as band antennas or dipoles, are a fundamental type of radio antenna consisting of two conductive elements, typically rods or wires, separated by a small gap. This gap is where the antenna is fed with radio frequency current from a transmitter or connected to a receiver. The length of these conductive elements is crucial to the antenna's performance. Ideally, each element is one-quarter of the wavelength of the radio wave it is intended to transmit or receive. When the antenna is resonant at a specific frequency, it efficiently radiates or absorbs radio energy at that frequency.

The simplest form is the half-wave dipole, where the total length of the antenna is approximately half a wavelength. This configuration provides a relatively omnidirectional radiation pattern in the plane perpendicular to the antenna elements. Bandenantennes can be operated at their fundamental resonant frequency or at odd harmonics of that frequency, allowing them to be used across multiple frequency bands, though with reduced efficiency at higher harmonics. Variations exist, such as folded dipoles, which offer a different impedance and can be more robust, and collinear dipoles, stacked to increase gain. Their simple construction, ease of deployment, and predictable performance make them a common choice for amateur radio operators and various professional applications.