| CPC H03F 1/26 (2013.01) [H03F 1/56 (2013.01); H03F 3/195 (2013.01); H03F 3/245 (2013.01); H03F 2200/294 (2013.01); H03F 2200/451 (2013.01)] | 4 Claims |
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1. A semiconductor device comprising:
an input terminal to which a radio-frequency signal is to be input;
an output terminal from which a signal obtained by amplifying the radio-frequency signal is to be output;
a first power supply terminal;
a first transistor having a gate terminal, a source terminal, and a drain terminal;
a second transistor having a gate terminal, a source terminal, and a drain terminal;
a second power supply terminal; and
a first resistance element,
a first coil; and
a second coil, wherein
the gate terminal of the first transistor is connected to the input terminal,
the source terminal of the first transistor is connected to the first power supply terminal,
the drain terminal of the first transistor is connected to the second power supply terminal via the first coil,
the drain terminal of the first transistor is further connected to the output terminal,
the gate terminal of the first transistor and the drain terminal of the first transistor are connected to each other via the first resistance element,
the source terminal of the second transistor is connected to the first power supply terminal,
the gate terminal of the second transistor and the drain terminal of the second transistor are short-circuited at a first node, the first node being connected to the gate terminal of the first transistor via the second coil, and
in a low-frequency region lower than a frequency band of the radio-frequency signal,
an impedance of the first resistance element is lower than an impedance of a parasitic capacitance between the gate terminal of the first transistor and the drain terminal of the first transistor, and is lower than an impedance of a parasitic capacitance between the gate terminal of the first transistor and the source terminal of the first transistor.
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