A Simple Economical Building FDNR Blocks with Modern Operational Amplifiers

摘要

Active RC filters designed using non-cascade filter synthesis method exhibit some advantages - namely low sensitivities. However these parameters are paid on the other hand due to the necessity to use more complicated building blocks which should be able to realize a circuit simulation of required ideal RLC ladder prototype elements (e.g., ideal inductors). That fact unfortunately brings higher filter sensitivities to real parasitic properties of active function blocks.rnUsage of new modern active elements (operational amplifiers with high GBW) and possibilities of goal-directed lossy RLC ladder prototypes enables to design optimized ARC filter realizations with simple and economic active building blocks. These simple grounded active selective blocks working only with one active element enable in present time to design active filters with optimized parameters and minimized influence of real active elements for frequency range up 1 MHz. In paper here are some parameters of simple and economic building selective blocks with modern active elements at higher frequencies discussed and briefly new possibilities of ARC lowpass filter optimization in some practical examples presented.