| 摘要 |
One end of a first transmission line 3 is connected to the collector of an HBT 2 with the base connected to an output terminal of an input-side matching circuit 1 and with the emitter grounded, and one end of an end-open stub 4 for blocking the passage of the doubled wave is connected to the other end of the first transmission line 3. One end of a second transmission line 5 is connected to the other end of the first transmission line 3, and one end of an end-open stub 6 for blocking the passage of the fundamental wave is connected to the other end of the second transmission line 5. An input terminal of an output-side matching circuit 7 is connected to the other end of the second transmission line 5. The fundamental wave is reflected toward the HBT 2 at the connecting point of the end-open stub 6 for blocking the passage of the fundamental wave, while the doubled wave is reflected toward the HBT 2 at the connecting point of the end-open stub 4 for blocking the passage of the doubled wave, by which only harmonics of quadrupled wave or higher-ordered waves are outputted via the output-side matching circuit 7. Thus, the frequency multiplier is capable of taking out fourth- or higher-ordered harmonics efficiently with a simple constitution using one high frequency transistor, and can be reduced in size and stabilized in operation. <IMAGE> |
