Antenna array feeding networks are used to distribute the input signal to the individual elements of an antenna array. There are several types of feeding networks commonly used in antenna arrays. Here are some of the main types:
Corporate Feed: In a corporate feed, the input signal is split and distributed equally to each element in the array. This is achieved using power dividers or couplers. Corporate feeds are often used in linear arrays where all elements are fed in phase.
Series Feed: In a series feed, the elements of the antenna array are connected in series, and the input signal is sequentially passed through each element. The series feed allows for amplitude and phase control of the signal at each element, enabling beam steering and shaping.
Corporate-Series Feed: The corporate-series feed combines aspects of both the corporate feed and series feed. It typically uses power dividers to distribute the signal equally to multiple branches, and each branch then sequentially feeds the elements in a series configuration.
Butler Matrix: A Butler matrix is a beamforming network used in phased array antennas. It is a planar matrix of power dividers and phase shifters that provides multiple beam outputs with precise control over beam direction and beamwidth. Butler matrices are commonly used in applications where beamforming and beam scanning are required, such as radar systems.
Rotman Lens: A Rotman lens is a beamforming network that provides beam steering capabilities in phased array antennas. It consists of a dielectric lens with a series of curved transmission lines and phase shifters. The Rotman lens allows for wide-angle scanning of beams with low losses and high efficiency.
These are just a few examples of antenna array feeding networks. The choice of feeding network depends on the specific requirements of the antenna array, such as beamforming capabilities, beam scanning range, and complexity of the system. Different feeding network designs offer different advantages in terms of beam control, directivity, and performance.