| 摘要 |
PURPOSE: A low noise amplifying device in a mobile communication system is provided to simultaneously satisfy an NFmin point and an input power gain matching point in a low noise amplifier of a terminal receiver, so as to easily carry out a matching process of a first end amplifier of the receiver and to increase a dynamic range by a feedback function. CONSTITUTION: An input matching circuit(11) performs an input matching function of a received signal. A gate electrode is connected to an output terminal of the input matching circuit, and a source electrode is connected to a ground terminal in a first transistor(13). The gate electrode is connected to the ground terminal, and a drain electrode is connected to a drain electrode of the first transistor in a second transistor(15). A feedback circuit(17) is connected between a source electrode of the second transistor and the gate electrode of the first transistor. The feedback circuit performs a negative-feedback function for an output of the second transistor, and applies the output to the gate electrode of the first transistor. An output matching circuit(19) carries out a matching function for a signal outputted from the source electrode of the second transistor.
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