  We present an analysis of time-delayed feedback control used to stabilize an
unstable steady state of a neutral delay differential equation. Stability of
the controlled system is addressed by studying the eigenvalue spectrum of a
corresponding characteristic equation with two time delays. An analytic
expression for the stabilizing control strength is derived in terms of original
system parameters and the time delay of the control. Theoretical and numerical
results show that the interplay between the control strength and two time
delays provides a number of regions in the parameter space where the
time-delayed feedback control can successfully stabilize an otherwise unstable
steady state.
