Improved method for designing linear distributed feedback systems

A new BIBO‐type stability criterion is proven for linear systems described by partial differential operators with constant coefficients. The class of inputs contains functions which are step‐like in time and which decay appropriately in the space variables. On the basis of this result, a frequency domain synthesis procedure was developed leading to an ‘economic’ feedback loop (i.e. significant noise reduction achieved). The procedure is illustrated by means of an example.