  We present a phase condition under which there is no suitable multiplier for
a given continuous-time plant. The condition can be derived from either the
duality approach or from the frequency interval approach. The condition has a
simple graphical interpretation, can be tested in a numerically efficient
manner and may be applied systematically. Numerical examples show significant
improvement over existing results in the literature. The condition is used to
demonstrate a third order system with delay that is a counterexample to the
Kalman Conjecture.
