| 摘要 |
<p>1. Switched capacities filter simulating a filter with inductancies and capacities, comprising a plurality of operational amplifiers (A1, A2, etc.), the input of each being connected to the output of one or a plurality of others or eventually of the same through switched or unswitched capacities, characterized in that the connections between operational amplifiers, in order to obtain a pass band characteristic, comprise the following connections : an unswitched capacity (C"11, C88) in parallel with a switched capacity (11, 88) between the output and the input of the first (A1) and the last (A8) operational amplifiers and an unswitched respective capacity (C22 to C77) in parallel between the output and the input of each of the intermediate amplifiers (A2 to A7) ; a switched capacity (12) without delay between the input of the first and the output of the second amplifier, another one (32) between the input of the third and the output of the second and still another one between the input of the third and the output of the fourth (34) ; an inverting switched capacity with delay (21) between the input of the second operational amplifier and the output of the first, and another one (23) between this same input and the output of the third amplifier ; an unswitched capacity (C'13) between the input of the first amplifier and the output of the third, another one (C'15) between this same input and the output of the fifth, a further one (C31) between the input of the third and the output of the first amplifier, and finally another one (C35) between this same input of the third and the output of the fifth.</p> |
