VARIABLE-DIRECTIVITY ANTENNA, ELECTRONIC DEVICE USING THE SAME AND METHOD FOR CONTROLLING ANTENNA DIRECTIVITY USING THE ANTENNA

摘要

PROBLEM TO BE SOLVED: To provide a variable-directivity antenna whose size is equal to that of an omnidirectional antenna, and a mobile phone and an information terminal equipped with the variable-directivity antenna.;SOLUTION: The variable-directivity antenna adopts a coaxial line composed of a signal line 111 and a ground conductor 112, and a monopole antenna composed of a radiator 12 and a ground plate 13 as an omnidirectional antenna. A short circuit line 15 and a switch 14 are connected to a connection part of the coaxial line 11 and the monopole antenna (radiator 12) in four directions. The switch 14 is controllable from the outside. The radiation pattern of the antenna remains omnidirectional when all the switches 14 are turned off. The radiation pattern of the antenna becomes to possess directivity, since the electric field in the coaxial line 11 is disturbed when only one of four switches 14 is turned on. The directivity can be switched by switching the switches.;COPYRIGHT: (C)2005,JPO&NCIPI