Popov's stability criterion

Popov's stability criterion

[pä′pȯfs stə′bil·əd·ē krī‚tir·ē·ən]
(control systems)
A frequency domain stability test for systems consisting of a linear component described by a transfer function preceded by a nonlinear component characterized by an input-output function), with a unity gain feedback loop surrounding the series connection.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.