• Login
    View Item 
    •   Home
    • Graduate Theses, Dissertations and Projects
    • Queen's Graduate Theses and Dissertations
    • View Item
    •   Home
    • Graduate Theses, Dissertations and Projects
    • Queen's Graduate Theses and Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Operational Transconductance Amplifiers For Gigahertz Applications

    Thumbnail
    View/Open
    Zheng_You_200809_PhD.pdf (8.339Mb)
    Date
    2008-09-19
    Author
    Zheng, You
    Metadata
    Show full item record
    Abstract
    A novel CMOS operational transconductance amplifier (OTA) is proposed and demonstrated in this thesis. Due to its feedforward-regulated cascode topology, it breaks the previous OTA frequency limit of several hundred MHz and operates at frequencies up to 10 GHz with a large transconductance. This is confirmed by an in-depth high-frequency analysis, simulations, and experimental demonstrations using purpose-built circuits. Experimental results also show that the proposed OTA has high linearity and low intermodulation distortion, which is of particular interest in microwave circuits. The OTA’s noise behavior and the effects of process variations, device mismatch, and power supply noise on the transconductance are also studied. To the best of our knowledge, the noise analysis here is the first of its kind on regulated cascode circuits, which can be applied to other regulated cascodes with minor changes.

    Three microwave applications of this OTA are explored in this thesis: 1) an active bandpass filter with a wide tuning range, 2) a 2.4-GHz ISM-band variable phase shifter, and 3) a microwave active quasi-circulator, which are all in CMOS MMIC form. These three circuits can be easily integrated with other chip components for System-on-Chip (SoC) realizations. The use of the OTA makes these three applications super compact: the active filter is at least 5 times smaller than previous circuits with a similar topology, and the phase shifter and quasi-circulator are at least 3 times smaller than previous works in that frequency range. Furthermore, the tunability of the developed OTA on its transconductance gives its applications extra freedom in tuning their frequencies and gains/losses electronically. In the first application, the active bandpass filter has a novel narrowband-filtering topology and has a wide tuning-range of 28% around 1.8 GHz, which makes it very suited for reconfigurable multi-band wireless systems. In the second and third applications, the active variable phase shifter has a comparable variable phase shift range of 120º in the 2.4-GHz ISM band and the active quasi-circulator has transmissions close to 0 dB and directivities over 24 dB from 1.5 GHz to 2.7 GHz.
    URI for this record
    http://hdl.handle.net/1974/1446
    Collections
    • Queen's Graduate Theses and Dissertations
    • Department of Electrical and Computer Engineering Graduate Theses
    Request an alternative format
    If you require this document in an alternate, accessible format, please contact the Queen's Adaptive Technology Centre

    DSpace software copyright © 2002-2015  DuraSpace
    Contact Us
    Theme by 
    Atmire NV
     

     

    Browse

    All of QSpaceCommunities & CollectionsPublished DatesAuthorsTitlesSubjectsTypesThis CollectionPublished DatesAuthorsTitlesSubjectsTypes

    My Account

    LoginRegister

    Statistics

    View Usage StatisticsView Google Analytics Statistics

    DSpace software copyright © 2002-2015  DuraSpace
    Contact Us
    Theme by 
    Atmire NV