| 摘要 |
PURPOSE:To suppress the occurrence of spuriousness by performing angle modulation without deteriorating characteristics, such as linearity, by performing the angle modulation of a signal higher in frequency than a normal carrier signal and by mixing this signal and a lower-frequency signal together. CONSTITUTION:The output of a quartz oscillator 31 outputting a carrier signal f1 higher in frequency than a normal carrier signal is supplied to a stereo adaptor 12 together with audio signals of channels R and L. This adapter 12 outputs an angle- modulated carrier signal Vc(t) and a synthesized sound signal Ve(t). The output of an oscillator 32 for a signal f2 lower in frequency than the signal f1 is inputted to a mixer 33 together with the angle-modulated carrier signal to generate a normal carrier signal f0. Consequently, since the frequency is high, angle modulation is performed without deteriorating characteristics, such as linearity, and two signals inptted to a power amplifier 24 synchronized with each other, so the occurrence of spuriousness is suppressed. |
