Talk:William F. Egan

Years
https://magazine.scu.edu/classnote/william-f-egan/

Additional refs
In 1981, describing high-order loops, William Egan conjectured that the addition of the zero pole to the loop filter's transfer function causes the hold-in and pull-in (acquisition) ranges to be theoretically infinite, i.e. that the hold-in and pull-in ranges of type 2 PLL are theoretically infinite: "The most common additional singularities are a low-frequency zero and a very-low-frequency pole (Fig.7.5d), essentially at zero frequency in many cases (see Fig. 7.5c), so that the hold-in range and acquisition range became theoretically infinite. That is, for the simplified model, they are infinite, although circuit limitations, such as finite VCO tuning range, will cause them to be finite". In his book, published in 1998, he wrote that "We might also say that significant deviations occur when \Omega_{PI} is approached for the lag-lead filter; this is to be expected since the type 2 loops have infinite \Omega_{PI}." Later similar statement was formulated in various articles and books.

In 1986, Egan's conjecture (without ref to his original work) was published in [https://ipnpr.jpl.nasa.gov/progress_report/42-86/86K.PDF Aguirre, S., Brown, D.H., and Hurd, W.J. (1986). Phase Lock Acquisition for Sampled Data PLL's Using the Sweep Technique. TDA Progress Report 4, 86, 95-102], page 96: "an analog PLL with a type II loop has an infinite pull-in range".

In Bandwidth Variation, A Fully Differential Phase-Locked Loop With Reduced Loop, 2011 the statement of Egan's conjecture is provided on page 22 without ref to Egan.

Amr M. Fahim noted in his book that "in order to have an infinite capture range, an active filter must be used for the loop filter".

Similar statement can be found in [https://link.springer.com/chapter/10.1007%2F1-4020-8080-8_2 (2005) Phase-Locked Loop Fundamentals. In: Clock Generators for SOC Processors. Springer, Boston, MA] on page 6 (there is ref to Egan's book 1990 - see ref 13).

Since additional refs have been provided, thus I removed the BLP primary sources template.

nk (talk) 09:37, 4 June 2020 (UTC)

Additional explanations
I suggest to add the corresponding figure: Baseband model of type 2 analog PLLs.



Milich64 (talk) 15:44, 22 June 2020 (UTC)

Feedback from New Page Review process
I left the following feedback for the creator/future reviewers while reviewing this article: Good start!.

North8000 (talk) 01:19, 30 June 2020 (UTC)