Cancellation of OpAmp virtual ground imperfections by a negative conductance applied to improve RF receiver linearity

    Research output: Contribution to journalArticleAcademicpeer-review

    23 Citations (Scopus)
    70 Downloads (Pure)

    Abstract

    High linearity CMOS radio receivers often exploit linear V-I conversion at RF, followed by passive down-mixing and an OpAmp-based Transimpedance Amplifier at baseband. Due to nonlinearity and finite gain in the OpAmp, virtual ground is imperfect, inducing distortion currents. This paper proposes a negative conductance concept to cancel such distortion currents. Through a simple intuitive analysis, the basic operation of the technique is explained. By mathematical analysis the optimum negative conductance value is derived and related to feedback theory. In- and out-of-band linearity, stability and Noise Figure are also analyzed. The technique is applied to linearize an RF receiver, and a prototype is implemented in 65 nm technology. Measurement results show an increase of in-band IIP3 from 9dBm to >20dBm, and IIP2 from 51 to 61dBm, at the cost of increasing the noise figure from 6 to 7.5dB and <10% power penalty. In 1MHz bandwidth, a Spurious-Free Dynamic Range of 85dB is achieved at <27mA up to 2GHz for 1.2V supply voltage.
    Original languageEnglish
    Pages (from-to)1112-1124
    Number of pages13
    JournalIEEE journal of solid-state circuits
    Volume49
    Issue number5
    DOIs
    Publication statusPublished - 1 May 2014

    Fingerprint

    Operational amplifiers
    Noise figure
    Defects
    Radio receivers
    Feedback
    Bandwidth
    Electric potential

    Keywords

    • EWI-24666
    • IR-91061
    • METIS-304065
    • Receiver linearity
    • Interference robustness
    • Compression
    • Blocking
    • in-band and out-band IIP3
    • IIP2
    • Mixer-first receiver architecture
    • transimpedance amplifier (TIA)
    • Negative conductance technique
    • CMOS
    • Wideband base station receiver
    • Software radio
    • Software defined radio
    • Cognitive radio (CR)

    Cite this

    @article{c5d16657ea34416d96c5e8b78cb4310a,
    title = "Cancellation of OpAmp virtual ground imperfections by a negative conductance applied to improve RF receiver linearity",
    abstract = "High linearity CMOS radio receivers often exploit linear V-I conversion at RF, followed by passive down-mixing and an OpAmp-based Transimpedance Amplifier at baseband. Due to nonlinearity and finite gain in the OpAmp, virtual ground is imperfect, inducing distortion currents. This paper proposes a negative conductance concept to cancel such distortion currents. Through a simple intuitive analysis, the basic operation of the technique is explained. By mathematical analysis the optimum negative conductance value is derived and related to feedback theory. In- and out-of-band linearity, stability and Noise Figure are also analyzed. The technique is applied to linearize an RF receiver, and a prototype is implemented in 65 nm technology. Measurement results show an increase of in-band IIP3 from 9dBm to >20dBm, and IIP2 from 51 to 61dBm, at the cost of increasing the noise figure from 6 to 7.5dB and <10{\%} power penalty. In 1MHz bandwidth, a Spurious-Free Dynamic Range of 85dB is achieved at <27mA up to 2GHz for 1.2V supply voltage.",
    keywords = "EWI-24666, IR-91061, METIS-304065, Receiver linearity, Interference robustness, Compression, Blocking, in-band and out-band IIP3, IIP2, Mixer-first receiver architecture, transimpedance amplifier (TIA), Negative conductance technique, CMOS, Wideband base station receiver, Software radio, Software defined radio, Cognitive radio (CR)",
    author = "D.H. Mahrof and Klumperink, {Eric A.M.} and Z. Ru and {Oude Alink}, M.S. and Bram Nauta",
    note = "eemcs-eprint-24666",
    year = "2014",
    month = "5",
    day = "1",
    doi = "10.1109/JSSC.2013.2294637",
    language = "English",
    volume = "49",
    pages = "1112--1124",
    journal = "IEEE journal of solid-state circuits",
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    publisher = "IEEE",
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    Cancellation of OpAmp virtual ground imperfections by a negative conductance applied to improve RF receiver linearity. / Mahrof, D.H.; Klumperink, Eric A.M.; Ru, Z.; Oude Alink, M.S.; Nauta, Bram.

    In: IEEE journal of solid-state circuits, Vol. 49, No. 5, 01.05.2014, p. 1112-1124.

    Research output: Contribution to journalArticleAcademicpeer-review

    TY - JOUR

    T1 - Cancellation of OpAmp virtual ground imperfections by a negative conductance applied to improve RF receiver linearity

    AU - Mahrof, D.H.

    AU - Klumperink, Eric A.M.

    AU - Ru, Z.

    AU - Oude Alink, M.S.

    AU - Nauta, Bram

    N1 - eemcs-eprint-24666

    PY - 2014/5/1

    Y1 - 2014/5/1

    N2 - High linearity CMOS radio receivers often exploit linear V-I conversion at RF, followed by passive down-mixing and an OpAmp-based Transimpedance Amplifier at baseband. Due to nonlinearity and finite gain in the OpAmp, virtual ground is imperfect, inducing distortion currents. This paper proposes a negative conductance concept to cancel such distortion currents. Through a simple intuitive analysis, the basic operation of the technique is explained. By mathematical analysis the optimum negative conductance value is derived and related to feedback theory. In- and out-of-band linearity, stability and Noise Figure are also analyzed. The technique is applied to linearize an RF receiver, and a prototype is implemented in 65 nm technology. Measurement results show an increase of in-band IIP3 from 9dBm to >20dBm, and IIP2 from 51 to 61dBm, at the cost of increasing the noise figure from 6 to 7.5dB and <10% power penalty. In 1MHz bandwidth, a Spurious-Free Dynamic Range of 85dB is achieved at <27mA up to 2GHz for 1.2V supply voltage.

    AB - High linearity CMOS radio receivers often exploit linear V-I conversion at RF, followed by passive down-mixing and an OpAmp-based Transimpedance Amplifier at baseband. Due to nonlinearity and finite gain in the OpAmp, virtual ground is imperfect, inducing distortion currents. This paper proposes a negative conductance concept to cancel such distortion currents. Through a simple intuitive analysis, the basic operation of the technique is explained. By mathematical analysis the optimum negative conductance value is derived and related to feedback theory. In- and out-of-band linearity, stability and Noise Figure are also analyzed. The technique is applied to linearize an RF receiver, and a prototype is implemented in 65 nm technology. Measurement results show an increase of in-band IIP3 from 9dBm to >20dBm, and IIP2 from 51 to 61dBm, at the cost of increasing the noise figure from 6 to 7.5dB and <10% power penalty. In 1MHz bandwidth, a Spurious-Free Dynamic Range of 85dB is achieved at <27mA up to 2GHz for 1.2V supply voltage.

    KW - EWI-24666

    KW - IR-91061

    KW - METIS-304065

    KW - Receiver linearity

    KW - Interference robustness

    KW - Compression

    KW - Blocking

    KW - in-band and out-band IIP3

    KW - IIP2

    KW - Mixer-first receiver architecture

    KW - transimpedance amplifier (TIA)

    KW - Negative conductance technique

    KW - CMOS

    KW - Wideband base station receiver

    KW - Software radio

    KW - Software defined radio

    KW - Cognitive radio (CR)

    U2 - 10.1109/JSSC.2013.2294637

    DO - 10.1109/JSSC.2013.2294637

    M3 - Article

    VL - 49

    SP - 1112

    EP - 1124

    JO - IEEE journal of solid-state circuits

    JF - IEEE journal of solid-state circuits

    SN - 0018-9200

    IS - 5

    ER -