| 摘要 |
PURPOSE:To attain low cost, small size and high accuracy by switching the clock and the capacitance of a capacitor so as to decrease number of filters. CONSTITUTION:A switched capacitor filter SCF 19 consists mainly of a switched capacitor integration device and is constituted as a leap frog SCF realizing a transmission characteristic as an LC lattice filter by simulating a voltage and a current of each element of the LC lattice filter. Thus, when a reception signal is given to the SCF 19, a variable frequency division circuit 30 and a variable band SCF are used in common, and thereby four ways of the transmission characteristics suitable for the CCITT standards, the Bell standards, a high group filter and a low group filter are realized with only one SCF. |
