| 摘要 |
PURPOSE:To reduce an output voltage of a drain power supply and power consumption by applying a drain bias directly to a drain of a FET provided between input an output matching circuits so as to eliminate a loss due to a voltage drop caused by the insertion of the output side matching circuit. CONSTITUTION:A drain bias terminal 12, output and input side matching circuits 13, 14, MMIC input output terminals 16,17 and a FET 11 connecting to the circuits 13, 14 are formed on a semiconductor substrate 10. Input/output DC cut-off capacitors 18, 19 are connected to the terminals 16, 17, and the FET 11 and a terminal 111 connecting to the terminal 12 form a drain bias circuit. Thus, a loss of a voltage drop due to the insertion of the circuit 13 is avoided and a DC equivalent circuit of the drain bias circuit is only a drain-source resistance of the FET 11. Thus, a drain bias is applied to the terminal 111 directly, a low voltage is adopted for the voltage of a drain power supply and power consumption of an amplifier is reduced. |
