| 摘要 |
PURPOSE:To eliminate trapping in an intermediate frequency signal band by connecting a tip-grounded line which is a quarter as long as wavelength or whose length is an odd multiple of it in parallel to a proper position of the high- frequency side main line of a mixer circuit. CONSTITUTION:A reception input signal is inputted from a terminal 1 through a reception-input side filter circuit 12. A mixer diode 24 generates an intermediate frequency signal from the input signal and the output signal of a local oscillator 23. This intermediate frequency signal is outputted from a terminal 2 through an intermediate-frequency output side filter 25. Intermediate-frequency trap removing circuits 37 and 38 are provided to proper positions of the main line 39 on the reception input side and local oscillation side. Those circuits 37 and 38 are a parallel stub circuits which has a tip grounded and line length that is an odd multiple of the quarter wavelength of the reception input signal or local oscillation signal. Consequently, the trapping in the intermediate frequency signal band is eliminated. |
