Analog active filters
Abstract
The evolution of active filters during the time from 1920 to 1980 is considered, taking into account the hardware used to implement a filtering network for voice frequency over 60 years. From 1920 to 1960 the majority of voice-frequency filters was realized as discrete RLC networks. After the development of transistors, it was realized that size and cost reductions could be achieved by replacing the inductors with active networks. In the early 1970's, batch-processed thin-film hybrid integrated circuits began to be employed. The synthesis of transfer functions which are predominantly input/output types is considered. Attention is given to direct realizations, synthesis using component simulation, cascade synthesis, multiple-loop feedback design, active-R and active-C filters, aspects of sensitivity, and switched-capacitor filters.
- Publication:
-
IEEE Transactions on Circuits Systems
- Pub Date:
- January 1984
- Bibcode:
- 1984ITCS...31...13G
- Keywords:
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- Analog Circuits;
- Electronic Filters;
- Network Synthesis;
- Operational Amplifiers;
- Rlc Circuits;
- Transistor Circuits;
- Audio Frequencies;
- Cascade Control;
- Computerized Simulation;
- Electric Filters;
- Feedback Circuits;
- Frequency Response;
- Hybrid Circuits;
- Integrated Circuits;
- Negative Resistance Circuits;
- Electronics and Electrical Engineering