| 摘要 |
PROBLEM TO BE SOLVED: To obtain the high frequency power amplifier with an improved efficiency by decreasing its power loss. SOLUTION: Each length of a drain bias line 11 and signal lines 12, 14, 15 is selected so that an output matching circuit 4 acts like an open load with respect to a second harmonic and like a short-circuit load with respect to a third harmonic, for example, a phase of an S11 of an S parameter with respect to the second harmonic ranges between -80 deg.C and 140 deg.C and a phase of an S11 of an S parameter with respect to the third harmonic ranges between 160 deg. and 220 deg.. Furthermore, the length of each line is adjusted so that a phase of an S22 of an S parameter with respect to the fundamental wave in an input matching circuit 3 is shifted by a phase of +5 deg. to -75 deg. from a point at which a maximum gain is obtained. |
