Current-mode operational transconductance amplifier-capacitor biquad filter structures based on Tarmy-Ghausi Active-RC filter and second-order digital all-pass filters

D. V. Kamat, P. V. Ananda Mohan, K. Gopalakrishna Prabhu

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

The Tarmy-Ghausi (TG) active resistor-capacitor (RC) filters using op-amps and its modification by Moschytz are well known to active RC filter designers. These use first-order all-pass networks in a negative feedback loop. New current-mode universal operational transconductance amplifier-capacitor (OTA-C) biquad filters based on the TG active RC filter are considered here. These are based on a recently proposed OTA-C based first-order all-pass network. Three different feedback arrangements are investigated in the proposed filter structure so as to reduce the pole-Q sensitivity. The proposed biquad filters are shown to implement all different types of filters like low-pass, high-pass, band-pass, symmetric notch, all-pass, low-pass notch and high-pass notch. The synthesis of the general biquad is carried out in a novel way by invoking the analogy with direct-form digital filter structures. The special case of all-pass filter realisation derived from the proposed universal filter needs additional hardware for realising the feed-forward coefficients. Hence alternative OTA-C based all-pass filter implementations based on Mitra-Hirano and Gray-Markel second-order digital filter structures are derived in which the coefficients that are used to realise the denominator are shared in the realisation of numerator also. All the proposed circuits are compared with the other structures available in the literature. The simulation results of the proposed circuits are also presented.

Original languageEnglish
Article numberICDSB4000004000004000346000001
Pages (from-to)346-364
Number of pages19
JournalIET Circuits, Devices and Systems
Volume4
Issue number4
DOIs
Publication statusPublished - 07-2010

Fingerprint

All-pass filters
Wave filters
Operational amplifiers
Digital filters
Resistors
Capacitors
Feedback
Networks (circuits)
Poles
Hardware

All Science Journal Classification (ASJC) codes

  • Control and Systems Engineering
  • Electrical and Electronic Engineering

Cite this

@article{da906078ae074728bd5fe629fdddf9c6,
title = "Current-mode operational transconductance amplifier-capacitor biquad filter structures based on Tarmy-Ghausi Active-RC filter and second-order digital all-pass filters",
abstract = "The Tarmy-Ghausi (TG) active resistor-capacitor (RC) filters using op-amps and its modification by Moschytz are well known to active RC filter designers. These use first-order all-pass networks in a negative feedback loop. New current-mode universal operational transconductance amplifier-capacitor (OTA-C) biquad filters based on the TG active RC filter are considered here. These are based on a recently proposed OTA-C based first-order all-pass network. Three different feedback arrangements are investigated in the proposed filter structure so as to reduce the pole-Q sensitivity. The proposed biquad filters are shown to implement all different types of filters like low-pass, high-pass, band-pass, symmetric notch, all-pass, low-pass notch and high-pass notch. The synthesis of the general biquad is carried out in a novel way by invoking the analogy with direct-form digital filter structures. The special case of all-pass filter realisation derived from the proposed universal filter needs additional hardware for realising the feed-forward coefficients. Hence alternative OTA-C based all-pass filter implementations based on Mitra-Hirano and Gray-Markel second-order digital filter structures are derived in which the coefficients that are used to realise the denominator are shared in the realisation of numerator also. All the proposed circuits are compared with the other structures available in the literature. The simulation results of the proposed circuits are also presented.",
author = "Kamat, {D. V.} and {Ananda Mohan}, {P. V.} and {Gopalakrishna Prabhu}, K.",
year = "2010",
month = "7",
doi = "10.1049/iet-cds.2009.0213",
language = "English",
volume = "4",
pages = "346--364",
journal = "IET Circuits, Devices and Systems",
issn = "1751-858X",
publisher = "Institution of Engineering and Technology",
number = "4",

}

Current-mode operational transconductance amplifier-capacitor biquad filter structures based on Tarmy-Ghausi Active-RC filter and second-order digital all-pass filters. / Kamat, D. V.; Ananda Mohan, P. V.; Gopalakrishna Prabhu, K.

In: IET Circuits, Devices and Systems, Vol. 4, No. 4, ICDSB4000004000004000346000001, 07.2010, p. 346-364.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Current-mode operational transconductance amplifier-capacitor biquad filter structures based on Tarmy-Ghausi Active-RC filter and second-order digital all-pass filters

AU - Kamat, D. V.

AU - Ananda Mohan, P. V.

AU - Gopalakrishna Prabhu, K.

PY - 2010/7

Y1 - 2010/7

N2 - The Tarmy-Ghausi (TG) active resistor-capacitor (RC) filters using op-amps and its modification by Moschytz are well known to active RC filter designers. These use first-order all-pass networks in a negative feedback loop. New current-mode universal operational transconductance amplifier-capacitor (OTA-C) biquad filters based on the TG active RC filter are considered here. These are based on a recently proposed OTA-C based first-order all-pass network. Three different feedback arrangements are investigated in the proposed filter structure so as to reduce the pole-Q sensitivity. The proposed biquad filters are shown to implement all different types of filters like low-pass, high-pass, band-pass, symmetric notch, all-pass, low-pass notch and high-pass notch. The synthesis of the general biquad is carried out in a novel way by invoking the analogy with direct-form digital filter structures. The special case of all-pass filter realisation derived from the proposed universal filter needs additional hardware for realising the feed-forward coefficients. Hence alternative OTA-C based all-pass filter implementations based on Mitra-Hirano and Gray-Markel second-order digital filter structures are derived in which the coefficients that are used to realise the denominator are shared in the realisation of numerator also. All the proposed circuits are compared with the other structures available in the literature. The simulation results of the proposed circuits are also presented.

AB - The Tarmy-Ghausi (TG) active resistor-capacitor (RC) filters using op-amps and its modification by Moschytz are well known to active RC filter designers. These use first-order all-pass networks in a negative feedback loop. New current-mode universal operational transconductance amplifier-capacitor (OTA-C) biquad filters based on the TG active RC filter are considered here. These are based on a recently proposed OTA-C based first-order all-pass network. Three different feedback arrangements are investigated in the proposed filter structure so as to reduce the pole-Q sensitivity. The proposed biquad filters are shown to implement all different types of filters like low-pass, high-pass, band-pass, symmetric notch, all-pass, low-pass notch and high-pass notch. The synthesis of the general biquad is carried out in a novel way by invoking the analogy with direct-form digital filter structures. The special case of all-pass filter realisation derived from the proposed universal filter needs additional hardware for realising the feed-forward coefficients. Hence alternative OTA-C based all-pass filter implementations based on Mitra-Hirano and Gray-Markel second-order digital filter structures are derived in which the coefficients that are used to realise the denominator are shared in the realisation of numerator also. All the proposed circuits are compared with the other structures available in the literature. The simulation results of the proposed circuits are also presented.

UR - http://www.scopus.com/inward/record.url?scp=77954649853&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77954649853&partnerID=8YFLogxK

U2 - 10.1049/iet-cds.2009.0213

DO - 10.1049/iet-cds.2009.0213

M3 - Article

VL - 4

SP - 346

EP - 364

JO - IET Circuits, Devices and Systems

JF - IET Circuits, Devices and Systems

SN - 1751-858X

IS - 4

M1 - ICDSB4000004000004000346000001

ER -