| 摘要 |
<p>PROBLEM TO BE SOLVED: To always make the antenna characteristic best in a state where a portable telephone set is placed in a free space and in a carried state when a main body is used with the earphone-microphone in the portable telephone set. SOLUTION: The portable telephone set is provided with a matching circuit 2 for the antenna 1 and the transmission/reception part 3 when the portable telephone set main body is used. The antenna matching circuit is provided with a plug connection detecting part 7 outputting a signal when the connection of the plug of the earphone-microphone to an earphone-microphone connection jack 9 is detected, a temperature sensor 8 outputting a first signal when the portable telephone set is in a free space and outputting a second signal while the portable telephone set is carried, and a switch part 4 switching a system so that an auxiliary matching circuit 5 is connected to the matching circuit 2 when the first signal from the temperature sensor 8 is outputted and the auxiliary matching circuit 6 is connected to the matching circuit 2 when the second signal from the temperature sensor 8 is outputted when the signal from the plug connection detecting part 7 is outputted.</p> |
