  In this paper we find a realization for the D'B'-boundary conditions, which
imposes vanishing normal derivatives of the normal components of the D and B
fields. The implementation of the DB boundary, requiring vanishing normal
components of D and B, is known. It is shown that the realization of the D'B'
boundary can be based on a layer of suitable metamaterial, called the
wave-guiding quarter-wave transformer, which transforms the DB boundary to the
D'B' boundary. In an appendix, the mixed-impedance boundary, which is a
generalization of both DB and D'B' boundaries, is shown to transform to another
mixed-impedance boundary through the same transformer.
