| 摘要 |
PROBLEM TO BE SOLVED: To provide a high frequency semiconductor amplifier having a high power addition efficiency.SOLUTION: A high frequency semiconductor amplifier 1 comprises an input terminal 10, an input matching circuit 12, a high frequency semiconductor amplifier 14, an output matching circuit 21 and an output terminal 18. The output matching circuit has a first transmission line 111 in which the electrical length ranges from 72 degrees to 108 degrees and the characteristic impedance is lower than 50 Ω, a second transmission line 112 in which the electrical length ranges from 18 degrees to 27 degrees and the characteristic impedance is lower than the characteristic impedance of the first transmission line, a third transmission line 113 in which the electrical length ranges from 18 degrees to 27 degrees, and the characteristic impedance is lower than the characteristic impedance of the first transmission line, and higher than the resistance component of the load impedance of the high frequency semiconductor amplification element, and a fourth transmission line 114 in which the electrical length ranges from 5 degrees to 10 degrees and the characteristic impedance is equal to the resistance component of the load impedance of the high frequency semiconductor amplification element.SELECTED DRAWING: Figure 1 |
