公开(公告)号：US3854098A

公开(公告)日：1974-12-10

申请号：US32602773

申请日：1973-01-23

Applicant: VICTOR COMPANY OF JAPAN

Inventor： TAKAHASHI N ,  SATO M ,  IWASAKI Y ,  NISIKAWA K

IPC: H04S3/00 ,  H03D3/18 ,  G11B3/04

CPC classification number: H04S3/006

Abstract: A demodulation system employs a phase locked loop. A multichannel disc demodulation circuit has a phase comparator of a differential amplifier type having an input circuit the input AC impedance of which is set at a relatively high value. The DC impedance of a base-bias circuit of input transistors of the phase comparator is set at a relatively low value. This demodulation circuit is capable of accomplishing demodulation without the occurrence of a phase difference when an amplitude variation occurs in the envelope of an angle-modulated wave introduced as input into the phase comparator.

Abstract translation: 解调系统采用锁相环。 多通道光盘解调电路具有差分放大器类型的相位比较器，该相位比较器具有其输入AC阻抗被设置为相对高的值的输入电路。 相位比较器的输入晶体管的基极偏置电路的直流阻抗被设定为相对较低的值。 当在作为相位比较器的输入引入的角度调制波的包络中发生振幅变化时，该解调电路能够进行解调而不发生相位差。