| 摘要 |
PROBLEM TO BE SOLVED: To realize a portable GPS receiver capable of saving more power in comparison with a conventional one. SOLUTION: This portable GPS receiver is provided with an antenna switching circuit 18 detecting electric current fed from a power source 14 to an RF circuit 20a inside an external antenna 20 via connection between connectors 10a and 20c when the connector 20c related to the external antenna 20 is connected to the connector 10a for connection with the external antenna 20 for interrupting power source voltage supply from the power source 14 to a built-in antenna 16.
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