A. N. Churilov
St.Petersburg State Marine Technical University,
Lotsmanskaya st., 3, 19008, St.Petersburg, Russia
A. Kh. Gelig
Academician V.I.Smirnov Institute
of Mathematics and Mechanics
of St.Petesburg State University,
Bibliotechnaya sq., 2, 198904, St.Petersburg, Russia
A wide class of pulse modulated systems with a stable linear part is considered. These systems are described by functional-integral equations with discontinuous nonlinear operators. With the help of the averaging method we obtain sufficient frequency conditions ensuring the absence of periodic modes whose period contains an integer number of pulses.