Читать книгу Spatial Multidimensional Cooperative Transmission Theories And Key Technologies - Lin Bai - Страница 32

An antenna is a device used to transmit and receive electromagnetic energy. In many cases, the task of transmitting and receiving electromagnetic energy can be performed well by a single radiator. Various commonly used antennas, such as the vibrator antenna, microstrip antenna, horn antenna, and reflector antenna, can work independently. However, once these antenna forms are selected, their radiation characteristics are relatively fixed, such as beam pointing, beam width, gain, and so on. And this leads to the fact that a single antenna cannot work and multiple antennas need to work together to form an array antenna in some special applications, such as shaped beams, multiple beams, and scanning beams.