| 摘要 |
PROBLEM TO BE SOLVED: To provide a low noise amplifier capable of increasing the variable gain dynamic range and a reception circuit with the amplifier. SOLUTION: The low noise amplifier comprises: an amplification part for which a MOS transistor TR 43 supplied with a control voltage Vcnt at the gate and a MOS transistor TR 42 whose gate is connected to a signal route are cascaded between a power source and a reference potential; a MOS transistor TR 41 whose source is grounded in terms of a high frequency and the drain is connected to the signal route; and a control circuit CONT for turning OFF the MOS transistor TR 41 when the control voltage is higher than a first level, turning ON the MOS transistor TR 41 when the control voltage is lower than a second level, and supplying control signals CTL capable of making the MOS transistor TR 41 function as a variable resistor to the gate of the MOS transistor TR 41 when the control voltage is at a level between the first level and the second level. COPYRIGHT: (C)2004,JPO
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