OTA-C biquad cells emulation of LC ladder filters [articol]

Abstract

The paper presents a method to design continuos-time filter based on the node-voltage simulation of LC ladder structures. The node voltages are used as variables to generate transfer functions. The OTA-C biquad cells are realized in distributed-feedback configuration and use node current injection to permit multiple input action. Both all-pole and finite-transmission-zeros LC low-pass and high-pass filters are implemented. Applying standard low pass to bandpass frequency transformation to OTA-C circuits capacitors, bandpass and bandstop filters are easily obtained from their low-pass or high-pass active filters prototypes.