| 摘要 |
PURPOSE:To reduce foldover noise generated in a DBM (double balanced mixer). CONSTITUTION:An LPF 14 is provided in the front end of the DMB 10. The LPF 14 is provided with a high-band cut-off frequency near a carrier frequency fCAR and by inputting signals low-band filtered by the LPF 14 before to the DBM 10, signal input for generating the foldover noise is interrupted in the DMB 10 and thus the foldover noise is reduced. |
