Sähköantenni

Sähköantenni, often translated as electric antenna or simply electrical antenna, refers to a component designed to transmit or receive electromagnetic waves. In the context of electrical engineering and telecommunications, antennas are crucial for wireless communication systems. They function by converting electrical energy into electromagnetic waves for transmission, or by converting incoming electromagnetic waves back into electrical energy for reception. The design and characteristics of a sähköantenni depend heavily on the specific frequencies it is intended to operate with and its intended application, which could range from radio broadcasting and television reception to mobile phone communication and satellite systems.

The fundamental principle behind a sähköantenni is the generation of oscillating electric and magnetic fields. When an alternating electric current flows through a conductor, it creates a changing magnetic field around it. This changing magnetic field, in turn, induces a changing electric field, and these fields propagate outwards as electromagnetic waves. Conversely, when an electromagnetic wave strikes a sähköantenni, it induces an alternating current in the conductor, which can then be processed by electronic equipment. Various types of sähköantenni exist, including dipoles, monopoles, parabolic antennas, and array antennas, each with its own advantages and disadvantages regarding gain, directivity, and bandwidth. The effectiveness of a sähköantenni is often measured by its gain, which indicates how well it concentrates power in a particular direction, and its radiation pattern, which describes the spatial distribution of its transmitted or received energy.