| 摘要 |
PURPOSE:To improve the conversion loss characteristic of a mixer by providing a stub whose tip is grounded through a through hole nearby the RF signal input side electrode of a mixer diode and a tip open stub nearby the IF signal output side electrode of the mixer diode, and thus eliminating the grounding inductance of the through hole. CONSTITUTION:When the tip grounded stub 15 is set to, for example, lambdag/4 in the RF signal frequency band, the impedance viewed from the RF signal implantation side electrode of the mixer diode 14 to the side of the tip grounded stub 15 is high in this frequency band. Then, the length of this stub is about 0.025 lambdag in the IF signal band and the impedance is sufficiently low. The tip open stub 16, on the other hand, is set to lambdag/4 in the RF signal band, so it operates for grounding in this frequency band. Thus, one electrode of the mixer diode is not grounded through the through hole, so the grounding inductance based upon the through hole is eliminated and the superior conversion loss characteristic is obtained.
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