| 摘要 |
PURPOSE:To separate each signal to be separated through conversion, by giving two or more signals with different frequency and local signals also different in frequency from each signal to a band pass filter through mixing. CONSTITUTION:A signal f1 in 100kHz and a signal f2 in 101kHz are given to a mixer 1. A local signal f3 in 10MHz oscillated from the 1st local oscillator 2 is given to the mixer 1 to convert the signal in 100kHz into a signal f4 in 10.1MHz and to convert the signal in 101kHz into a signal f5 in 10.101MHz. The signals f4 and f5 are given to a mixer 3. Local signals f6 and f7 different from frequency are given alternately to the mixer 3 from the 2nd local oscillator 4. The frequency of the local signals is the difference of frequencies of the signals f4 and f5 and the frequency of a band pass filter 5 at the next stage. Thus, when the local signal f6 is given to the mixer 3, only the signal f4 can be picked up as the output of the band pass filter 5. |
