| 摘要 |
PURPOSE:To obtain enough gain when a radio equipment is used while being carried with a human body by providing a switching means for the tuned or untuned state of a loop antenna and increasing the coupling degree of the loop antenna to the human body. CONSTITUTION:A switching means 12 connected to the both ends of a loop antenna 11 is composed of a choke coil L and diode. When a current (i) flows through the coil L to the diode, the impedance of the diode is decreased and a loop is formed by the antenna 11 and the diode. Next, when tuning is executed by a capacitor C for tuning in the loop and the inductance of the loop, an operation as an antenna is obtained. When the diode is not electrified, the loop is not formed and the antenna 11 is not operated as the antenna. The area of a close part 11c to the human body in the antenna 11 is enlarged and the antenna 11 is arranged almost parallelly to the mounting surface of the human body. Then, the metal part of an equipment is used for the part 11c. Thus, when the radio equipment is used while being carried with the human body, the enough gain can be obtained. |
