| 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 comprises a high frequency semiconductor amplification element for simplifying a signal, and an output matching circuit. The output matching circuit has a first transmission line in which the electrical length ranges from 72 degrees to 108 degrees at the center frequency and the characteristic impedance is lower than the impedance of an external load of 50 Ω, a second transmission line in which the electrical length ranges from 18 degrees to 27 degrees at the center frequency and the characteristic impedance is lower than the characteristic impedance of the first transmission line, a third transmission line in which the electrical length ranges from 18 degrees to 27 degrees at the center frequency, 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 in which the electrical length ranges from 5 degrees to 10 degrees at the center frequency, 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 |
