Comparative Study of Ladder Active-RC Filter Structures

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Patrakit Katchamat
Jirayut Mahattanakul


This paper presents a comparative analysis of the frequency response of various structures of the 3rd-order ladder active-RC filters. It was found that if the unity-gain frequency of the op amps employed in the filters is not high enough, the resulting filters would have peaking problem in their magnitude responses. In particular, three structures suffer peaking near the cut-off frequencies and one structure suffers peaking in the stop band. Simulation results were found to be in good agreement with the analytical results.

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