| 摘要 |
PROBLEM TO BE SOLVED: To realize antenna directivity control in an information terminal, provided with a variable directivity antenna using a comparatively simple configuration. SOLUTION: The information terminal 3 includes a transmitter/receiver 231 and a processing unit 232, and the variable directivity antenna 1 includes a main antenna 201 and a plurality of auxiliary antennas 202-207, to which the transmitter/receiver 231 directly supplies a high frequency signal. Variable phase shift circuits 212-217 deciding a phase shift of a reflection wave are respectively connected to each auxiliary antennas 202-207, a control circuit 220 receives directivity data 229 from a CPU 232 of the information terminal 3 and analyzes the data to control the phase shift of the variable phase shift circuits 212-217. The phase shift in each auxiliary antenna is adjusted, so that the wave fronts of radio waves emitted or emitted secondarily from the main antenna 201 and a plurality of the auxiliary antennas 202-207 coincide in a specific direction, and the variable directivity antenna 1 is controlled to have the directivity in the direction.
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