| 摘要 |
PURPOSE:To suppress as less as possible a modal noise and a modal distortion by supervising at least >=2 high frequency signals having sufficiently higher frequency component than that of a modulation signal and also different frequencies to each other on the modulation signal or switching regularly or irregularly high frequency signals having >=2 different frequencies in a switching speed higher than the frequency component of the said modulation signal so as to superimpose the high frequency signals onto the said modulation signal. CONSTITUTION:Output signals of a high frequency signal generator 11 of a frequency f1 and of a high frequency signal generator 12 of a frequency f2 are synthesized at a synthesizer 10 and the result is inputted to a mixer 3. As the frequencies f1, f2, they are selected to a value sufficiently higher than the frequency component of the modulation signal, e.g., 500MHz or 650MHz. The multiple oscillation longitudinal mode and spread of spectral width are progressed in this way, a spectrum is hardly caused and no waveform deterioration takes place. |
