| 摘要 |
PURPOSE:To remove phase distortion and suit a DC/AC type phase modulator to narrow band digital transmission by performing two pairs of signal processing by the 1st and 2nd balance modulating parts alternately. CONSTITUTION:The sine and cosine components of a signal (t) to be transmitted are switched alternately by the 1st switching part 14 and inputted to the 1st and 2nd balance modulating parts 16, 17 as signal waves and two carriers with pi/2 phase difference outputted from an oscillating part 13 are switched alternately by the 2nd switching part 15 locked with the signal switching of the 1st switching part 14 and inputted to the 1st and 2nd balance modulating parts 16, 17. Consequently the difference of the characteristics of signal processing between these balance modulating parts 16 and 17 is averaged and the phase distortion is reduced. |
