Antenniryhmät

Antenniryhmät, often translated as antenna arrays, are collections of individual antenna elements arranged in a specific geometric pattern. These elements are typically connected by a feed network, which distributes the radio frequency signal to each element or combines the signals received by them. The primary purpose of using an antenna array is to achieve a radiation pattern that is different from that of a single element. By carefully controlling the amplitude and phase of the signals fed to each element, or processed from them, the overall directional properties of the array can be manipulated. This allows for focused transmission or reception in a particular direction, or the creation of complex beam shapes.

The radiation pattern of an antenna array is a superposition of the patterns of its individual elements, modified by the spatial arrangement and the excitation of these elements. Arrays can be designed to produce highly directional beams, which are useful for long-distance communication, radar systems, and satellite tracking. They can also be used to create nulls in specific directions, suppressing interference from unwanted sources. Phased arrays are a significant type of antenna array where the phase of the signal fed to each element is electronically controlled, allowing the beam to be steered rapidly without physically moving the antenna. This electronic beam steering capability is crucial in modern radar and communication systems. Different arrangements of elements, such as linear, planar, or volumetric, lead to different array characteristics and applications.