A high open-loop gain controller

Heikki Seppä, Hannu Sipola

    Research output: Contribution to journalArticleScientificpeer-review

    12 Citations (Scopus)


    A new controller, especially suited for phase‐locked loops, is discussed. The controller, composed of RC‐circuit electronics, has a gain with a slope of −30 dB/decade over a wide bandwidth. It is shown that in certain systems the present controller (PI3/2 controller) provides a much higher feedback gain than an ordinary proportional‐integrator controller (PI controller).
    As applications, the superconducting quantum interference device (SQUID) and an electrically adjustable point contact used in surface microscopy or spectroscopy are discussed in some detail.
    The operation of the controller in a piezo‐driven point contact was studied experimentally.
    Original languageEnglish
    Pages (from-to)2449-2451
    JournalReview of Scientific Instruments
    Issue number9
    Publication statusPublished - 1990
    MoE publication typeA1 Journal article-refereed


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