| 摘要 |
PROBLEM TO BE SOLVED: To provide an improved antenna having two antenna elements or two-frequency ranges in antenna structure. SOLUTION: A 1st antenna element is a cylindrical coil conductor 2 forming a spiral antenna, and has a 1st section 2a and a 2nd section 2b. A 2nd antenna element 3 is combined with the cylindrical coil conductor by the fixed combining at a junction 2c which is at between the 1st and the 2nd sections 2a and 2b. The 2nd antenna element is a conductive pattern 5 formed on the surface of an insulating board 3, for example. A 1st operation frequency depends on the combination electrical length of the parts of the 1st antenna elements, and a 2nd operational frequency depends on the combination electrical length of the lower part of the 1st antenna element and the 2nd antenna element. The bandwidth of the operation frequency depends on the position of the junction in the 1st antenna element. |
