Reducing method for hum noise of modulator |
|||||||
| 申请号 | JP5763180 | 申请日 | 1980-04-30 | 公开(公告)号 | JPS56154807A | 公开(公告)日 | 1981-11-30 |
| 申请人 | Fujitsu Ltd; | 发明人 | YOKOE TOSHINORI; | ||||
| 摘要 | PURPOSE:To eliminate hum noise included in a DC power source by a simple circuit by canceling the hum noise by using a phase inverting amplifier. CONSTITUTION:Direct-current DC power source 1 including hum noise is supplied to modulator 6 and base band amplifier 7 and a base band signal from terminal 8 is supplied to modulator 6 via amplifier 7. The hum noise included in power source 1, on the other hand, is extracted through LPF10 and then inverted in phase by phase inverting amplifier 11. This output and the output of amplifier 7 are then supplied to modulator 6 via mixing circuit 12. Therefore, the hum noise is canceled and removed and only the signal having no noise is outputted from modulator 6. Thus, even the simple circuit is capable of eliminating the hum noise included in the DC power source. | ||||||
| 权利要求 | |||||||
| 说明书全文 | |||||||
QQ群二维码
意见反馈
意见反馈