Research output: Contribution to journal › Article › peer-review
In 1981, famous engineer William F. Egan conjectured that a higher-order type 2 PLL with an infinite hold-in range also has an infinite pull-in range, and supported his conjecture with some third-order PLL implementations. Although it is known that for the second-order type 2 PLLs the hold-in range and the pull-in range are both infinite, the present paper shows that the Egan conjecture may be not valid in general. We provide an implementation of the third-order type 2 PLL, which has an infinite hold-in range and experiences stable oscillations. This implementation and the Egan conjecture naturally pose a problem, which we will call the Egan problem: to determine a class of type 2 PLLs for which an infinite hold-in range implies an infinite pull-in range. Using the direct Lyapunov method for the cylindrical phase space we suggest a sufficient condition of the pull-in range infiniteness, which provides a solution to the Egan problem.
Original language | English |
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Article number | 9258948 |
Pages (from-to) | 1467-1471 |
Number of pages | 5 |
Journal | IEEE Transactions on Circuits and Systems II: Express Briefs |
Volume | 68 |
Issue number | 4 |
DOIs | |
State | Published - Apr 2021 |
ID: 73410588