| 摘要 |
The present invention is for providing an antenna device in a portable radio, capable of transmitting and receiving in frequency bands used in two different communication systems without the performance irregularity even in the case of the mass production. By having the inductance per unit length along the elongating direction of the upper antenna element larger than that of the lower antenna element, the entire antenna element is resonated at a first frequency f1 as a quarter wave ground antenna element and is also resonated at a second frequency f2 lower than the frequency three times as much as the first frequency f1 as a three quarter wave ground antenna. Since the antenna element is formed with an antenna pattern printed on a printed wiring board, antenna elements with the same shape can be obtained, and thus the antenna performance irregularity cannot be generated even in the case of the mass production. |
