| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an antenna device which is adaptive to three frequencies without increasing circuit scale, and has less antenna efficiency deterioration due to an obstacle. <P>SOLUTION: A first antenna element 15 has a branch structure of first, second branch elements 15A, 15B, a second antenna element 16 has a branch structure of third, fourth branch elements 16A, 16B, and a low coupling circuit 17 which increases in susceptance as the frequency increase is provided between the first and second antenna elements 15, 16. Further, the first and second antenna elements 15, 16 have resonance of a Y12 component of an admittance matrix between first and second frequencies as well as between second and third frequencies, the first and third branch elements 15A, 16A are substantially 1/4 as long as a resonance electric length of the Y12 component of the admittance matrix between the first and second frequencies, and the second and fourth branch elements 15B, 16B are substantially 1/4 as long as a resonance electric length of the Y12 component of the admittance matrix between the second and third frequencies. <P>COPYRIGHT: (C)2013,JPO&INPIT |
