| 摘要 |
PROBLEM TO BE SOLVED: To provide a reception high-frequency circuit including an LNA comprising an LNA protection circuit which quickly responds to an input signal level without stopping a receiving function and protects the LNA from excessive input, and prevents the LNA from being destroyed. SOLUTION: The circuit includes the LNA that includes positive/negative two power sources and does not lose an amplification function even when any one of positive and negative power sources is interrupted, an LNA inflow current detecting means in supplying power from both the positive and negative power sources, a means for deciding that an input signal level is excessive, from a current value, and a means for interrupting any one of the positive and negative power sources during excessive input. COPYRIGHT: (C)2008,JPO&INPIT
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