New antennas: Smart/reconfigurable/ferroelectric

Nowadays, radioelectronic systems employ multiple antenna systems. An intelligent (smart) or adaptive antennas are the most suitable for wireless communication, especially for 3G and 4G systems. Many solutions of the reconfigurable antennas have been described in the literature and their practical applications have been successfully used in telecommunication systems. In general, the reconfigurable antennas can be divided into two groups: One which uses fixed separated switches placed on the aperture (as switches can be used: PIN diodes, FET transistors or MEMS), One which uses temporarily created switches, e.g. on a semiconductor substrate.