  The inverse-scattering problem of an inhomogeneous material has been of
interest for many years, and was generally addressed with various optimization
techniques. In this paper, we suggest an optimization-free method for solving
the inverse-scattering problem of a one-dimensional inhomogeneous medium and
use this to demonstrate the design of desired reflection frequency response. In
addition, we derive the governing equation of an analog problem - a
time-dependent homogeneous medium and use the same technique to design a
temporal switching profile for the design of frequency response in k-space.
