| 摘要 |
PURPOSE:To attain double frequency multiplication with high accuracy over a very wide band by multiplying signals of the 1st and 2nd phase shift circuits whose output signals have a phase difference of 90 deg. over a broad band. CONSTITUTION:The 1st phase shift circuit 1 changing the phase of an audio band signal in a rate of -45 deg./oct, and the 2nd phase shift circuit 2 changing the phase of the audio band signal in a rate or 90 deg. and a multiplier circuit 4 are provided, and the result of multiplication is extracted as an output signal. The region of -45 deg./oct in the phase shift circuit 2 is region being 4 times of the frequency of the region of the -45 deg./oct in the phase shift circuit 1. In this case, the frequency being 4 times corresponds to the phase difference of 90 deg., and the relation of each output signal corresponds to the relation just between sin x and cos x, then the frequency of an input signal is doubled.
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