| 摘要 |
<p>PROBLEM TO BE SOLVED: To make the system and device small-sized and lightweight by providing a 2nd dielectric which is formed on one surface of a radiation conductor and a 2nd ground conductor which is formed opposite to the radiation conductor across the 2nd dielectric and short-circuited to a ground conductor. SOLUTION: The capacity can be increased by forming a plate type inverted F- shaped antenna in two-layered structure wherein a 1st antenna is formed of a radiation conductor 52 and a ground conductor 51 short-circuited by a plate type inverted F- shaped short-circuit conductor 14 and a 2nd antenna is formed of the radiation conductor 52 and an upper ground conductor 53 short-circuited by a flank ground conductor 54 and increasing the area part of the radiation conductor 52 used for the whole antenna operation by adding the 2nd area part S2 on one surface side of the radiation conductor used for 2nd antenna operation to the 1st area part S1 on the other surface side of the radiation conductor 52 used for 1st antenna operation. The resonance frequency can, therefore, be decreased without making the length (e) and width (f) larger than those of a general type. Consequently, when the antenna 27 is put in operation at the same frequency as the general type, the overall size is reducible by the size equivalent to the decreased resonance frequency and the area of the antenna mounted on the portable radio device is reducible.</p> |
