| 摘要 |
<p>PROBLEM TO BE SOLVED: To perform optimum communication by measuring a distance from an object positioned near an antenna and adjusting matching conditions corresponding to antenna characteristic change. SOLUTION: A portable telephone set 30 is provided with an antenna 1, a matching circuit 3 for matching impedance with the antenna 1, a distance measurement means 7 for measuring the distance between the antenna 1 and the object 10 by ultrasonic waves and a control means 5 as a circuit condition adjustment means for adjusting the matching circuit conditions of the matching circuit 3 corresponding to the distance measured in the distance measurement means 7. The ultrasonic waves reduce influence on the head part of a human body and measure the distance. The control means 5 sets the matching conditions calculated beforehand to the antenna matching circuit 3 corresponding to a distance measured result by the ultrasonic distance measurement means 7.</p> |
