ANTENNA DEVICE, AND MOBILE TERMINAL DEVICE COMPRISING SAME

摘要

PROBLEM TO BE SOLVED: To cover an overall frequency band to be used even with a few switches. SOLUTION: An antenna device 10A includes an antenna pattern 13A formed from a feed point 15 to a terminal 17 on a principal surface 11a of a substrate 11 and receives radio waves of frequency bands to be used between a lower limit frequency FL and an upper limit frequency FH. A double of the lower limit frequency is higher than the upper limit frequency (2×FL>FH>FL). The antenna pattern is configured to select 1st to 4th antenna lengths L1-L4 in a descending order from the longest one. The antenna device is operable in one of 1st to 4th operating modes corresponding to the 1st to 4th antenna lengths, respectively. The 1st to 4th antenna lengths are designed so that a resonant frequency of a higher harmonic wave to be determined by those lengths, respectively can be settled within the frequency band to be used. The 1st to 4th operating modes are combined and the antenna device 10A is operated to cover the frequency band to be used. COPYRIGHT: (C)2007,JPO&INPIT