| 摘要 |
PURPOSE: A device for confirming a connection of an antenna in a radio instrument and a method therefor are provided to remove a high frequency component, and to output an antenna connection confirmation signal by comparing a voltage change with a reference voltage, thereby reducing power consumption of the radio instrument. CONSTITUTION: A capacitor(201) is connected to an RF transmission line, and cuts off a DC component from flowing into the transmission line. An inductor(203) is connected to the capacitor(201), and removes a high frequency component incoming from the capacitor(201). The first resistor(205) distributes a voltage to the transmission line. The second and the third resistors(207,209) make a reference voltage. A comparator(215) is connected to the first, the second, and the third resistor(205,207,209), and compares a voltage change with the reference voltage.
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