| 摘要 |
<p>The apparatus operates on a time division multiplex communication system and includes a power amplifier circuit (12), signal processing circuit (11, 15), battery (20), stepping up circuit (23), storing circuit (24), and a switch circuit (21). The power amplifier circuit amplifies a transmitted signal intermittently transmitted at predetermined periods to a radio transmission power level. The signal processing circuit is operated by a voltage lower than the operating voltage of the power amplifier circuit. The battery is for example a battery constituted of a lithium ion battery, of which the unit cell has a full-charged voltage lower than the operating voltage of the power amplifier circuit and an ultimate voltage higher than the operating voltage of the signal processing circuit, with a large voltage difference between the full-charged voltage and the ultimate voltage. The stepping up circuit is a circuit with small output current capacity, operating at the voltage within the range changing from the full-charged voltage to the ultimate voltage of the battery, and amplifies the output voltage of the battery at least to the operating voltage of the power amplifier circuit. The storing circuit stores power of which the voltage is stepped up by the stepping up circuit. The switch circuit is provided between the storing circuit and the power-supply terminal of the power amplifier circuit and supplies the stored power in the storing circuit to the power amplifier circuit only while the power amplifier circuit is amplifying the transmitted signal in substance. <IMAGE></p> |
