| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide the booster for portable telephone set where no excess connection wire is required and to provide the booster for portable telephone set which is connected to any portable telephone set. SOLUTION: A decoder 16 decodes a specific message specifying transmission power included in a transmission wave from a portable telephone set and obtains a reference voltage. A control circuit 19 controls a gain of a variable gain power amplifier 13 so that a voltage obtained by detecting an output transmission wave of the variable gain power amplifier 13 at a diode 17 and a capacitor 18 is coincident with a reference voltage from the decoder 16. Thus, the transmission wave power-amplified by the variable gain power amplifier 13 is sent via an antenna 22 with the transmission power specified by the specific message. Thus, it is not required to give information denoting connection of the booster to the portable telephone set and then the need for a detection circuit to detect booster connection and its connection wire is eliminated.</p> |
