DIRECTIONAL ANTENNA, AREA CONTROL ANTENNA FOR RELAY SYSTEM, LONG DISTANCE COMMUNICATION SYSTEM AND SECURITY SYSTEM

摘要

A directional antenna comprising a rectangular loop antenna body (1) having a short side (2B) and a long side (2A) that is 2 to 3 times longer than the short side and equivalent to a 1/2 wavelength; and a pair of rectangular reflecting plates (8, 8) having a long side (44) of 1 to 2 times the length of the long side of the antenna body and a short side (45) of 1 to 3 times the length of the short side of the antenna body. The reflecting plates, which form a corner reflector (9), are joined into a V shape to fold the antenna body in the middle between them. Feed points (4, 4) are set in the positions at a distance of 1/3 to 1/4 from one of the ends of the long side of the antenna body, and the antenna body and corner reflector are integrated in reliable insulation on a support pole (6).