| 摘要 |
PURPOSE:To obtain the local oscillation frequency for the entire U-V band through the same circuit constitution by installing the voltage control type oscillator as well as the fixed oscillator featuring the frequency the several times as high as the upper limit frequency of the reception frequency band and then defying the difference of the frequencies between the two oscillators. CONSTITUTION:In the frequency range higher than the reception frequency region, the oscillation output of oscillators 36 and 37 which satisfies the relation of (the frequency of voltage control type oscillator 36-the oscillation frequency of fixed oscillator 37=the frequency of each channel+the intermediate frequency) receive the mixing conversion through mixer 35 for the local oscillator. Thus the local oscillation frequency is generated to be supplied to main mixer 32. As a result, the frequencies of oscillators 36 and 37 feature a high level of at least more than 2GHz, and thus the relative band width can be reduced relatively down to 50% or less to the maximam variable oscillation frequency in case the local oscillation frequency range 36 is within 1-2GHz. As a result, the local oscillation frequency of oscillator of the entire U-V band can be covered within the capacity variation range of the varactor diode, thus constituting the local oscillator into one body with U-V. |
