| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a radio LAN integrated-circuit device for consuming a low electric power by a simple constitution, and to provide a radio LAN system and a mobile telephone set using the device. <P>SOLUTION: The radio LAN integrated-circuit device amplifies a high-frequency signal received by an antenna by a high-frequency amplification circuit and down-converts it by a frequency conversion circuit. An output signal of the frequency conversion circuit is amplified by a variable gain amplification circuit and a receiving intensity is detected by a measuring circuit. An operation current of the variable gain amplification circuit is broken by a control circuit for a first term from starting a receiving mode until forming a gain rough-adjustment data of the variable gain amplification circuit maintaining the measuring circuit to be an operating state. The operation current is supplied to the variable gain amplification circuit for a second term after the first term is over by the control circuit, a gain setting is conducted by the gain rough-adjustment data 37, the gain setting is conducted by the gain rough-adjustment data generated based on the output signal of the variable gain amplification circuit, and the operation current of the measuring circuit is broken. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
