Antén

Antén is a term used in some languages to denote an antenna, a device that transmits or receives electromagnetic waves for communication and sensing. An antenna converts electrical signals into radio waves when transmitting and converts incoming waves back into electrical signals when receiving. Its performance depends on frequency, geometry, feed method, and the surrounding environment.

Several common forms exist. Dipole antennas are simple straight wires; folded dipoles use a folded conductor for different impedance. Loop antennas encircle a region with a closed conductor. Yagi-Uda antennas use multiple elements to achieve high directivity, while log-periodic antennas cover wide frequency bands. Microstrip or patch antennas are compact, often used in portable devices, and parabolic dish antennas provide high gain for satellite and radar applications. Antennas are typically fed via coaxial cables, balanced lines, or microstrip circuits, and may include baluns or matching networks to optimize impedance and reduce unwanted currents.

Key concepts include resonance, where antenna length is related to the wavelength of the operating frequency, and impedance matching to maximize power transfer. Radiation patterns describe how energy is emitted or received in space, with directivity and gain measuring focus. Polarization, bandwidth, efficiency, and return loss are important performance factors.

Applications span broadcasting, cellular networks, satellite communications, radar, Wi‑Fi, and RFID systems. Design considerations cover frequency band, physical size, mounting and weathering, mechanical stability, and regulatory compliance. Testing typically involves measuring VSWR or return loss, radiation patterns, gain, and efficiency.

Etymology traces the term to the Italian word antenna, historically related to yardarms or masts, with its radio usage established in the early 20th century as understanding of radiating conductors advanced.