| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-frequency reception circuit, in which weight reduction, downsizing and a low cost are realized by optimizing attenuation of a signal at an image reception frequency, that is decided depending on a frequency characteristics of a transistor(TR) amplifier circuit and of a mixer circuit, so as to eliminate the need for an stage band-pass filter between the TR amplifier circuit and the mixer circuit. SOLUTION: The high-frequency reception circuit includes the TR amplifier circuit 4, that amplifies a high-frequency signal and the mixer circuit 8 that down-converts the frequency of the high-frequency signal into an intermediate frequency. A transmission line 6 with an electrical length for bringing an output impedance of an output matching circuit 5 at the image reception frequency, to have the phase angle advanced from an input conjugate impedance by a 1/4 wavelength is connected between the output matching circuit 5, connected to an output of the TR amplifier circuit 4 and an input matching circuit 3, connected to the input of the mixer circuit 8 to attenuate the signal with the image reception frequency.
|
