All practical antennas are at least somewhat directional, although usually only the direction in the plane parallel to the earth is considered, and practical antennas can easily be omnidirectional in one plane.
The most common types are the yagi antenna, the log-periodic antenna, and the corner reflector, which are frequently combined and commercially sold as residential TV antennas. Cellular repeaters often make use of external directional antennas to give a far greater signal than can be obtained on a standard cell phone.
For long and medium wavelength frequencies, tower arrays are used in most cases as directional antennas.
Researchers Submit Patent Application, "Directional Antenna System for Portable Communication Device", for Approval
Nov 28, 2013; By a News Reporter-Staff News Editor at Politics & Government Week -- From Washington, D.C., VerticalNews journalists report that...
US Patent Issued to Nextel Communications on Dec. 21 for "System and Method for Manually Adjustable Directional Antenna" (Virginia Inventor)
Dec 22, 2010; ALEXANDRIA, Va., Dec. 22 -- United States Patent no. 7,856,206, issued on Dec. 21, was assigned to Nextel Communications Inc....