Amplification circuit

The invention provides an amplifying circuit which is a stable cascade connection type amplifying circuit capable of preventing oscillation. An amplifier circuit (1) is provided with: a power supply terminal (53) connected to a power supply (31); a transistor (20) having a source terminal (S1), a drain terminal (D1), and a gate terminal (G1) to which a high-frequency signal is input; a transistor(10) having a source terminal (S2) connected to the drain terminal (D1), a drain terminal (D2) for outputting a high-frequency signal, and a grounded gate terminal (G2); a capacitor (13) arranged in series on a second path connecting the gate terminal (G2) and the power supply terminal (53); and a switch (14) arranged in series on the first path or the second path. The drain terminal (D2) and thegate terminal (G2) are connected via the switch (14) and the capacitor (13). 提供一种放大电路，是防止了振荡的稳定的级联连接型的放大电路。放大电路(1)具备：与电源(31)连接的电源端子(53)；具有源极端子(S1)、漏极端子(D1)及被输入高频信号的栅极端子(G1)的晶体管(20)；具有与漏极端子(D1)连接的源极端子(S2)、输出高频信号的漏极端子(D2)及被接地的栅极