An explicit analysis of the retrodirective mechanism of a flattened dihedral using periodic arrays is proposed. Once flattened, a corner dihedral requires a phasing mechanism to restore its retrodirective behaviour. This can be achieved by equipping each of the panels with passive phase‐shifting cells that obey a global retrodirective phase law. The challenge is to have a trade‐off between two steering mechanisms on each side such that this global phase law is achieved. In this work, an analytical study of the reflection phenomenon between the two panels is presented and sufficient information are provided to predict the retrodirective performance affected by the dihedral geometrical configuration itself. The analytical formulation of the global phase law is thus defined along with other complementary formulations to provide a better understanding of the reflection phenomenon involved. Based on these analysis and comprehension, guidelines are suggested in terms of the cell design and the dihedral geometrical configuration so that to efficiently engineer the retrodirective profile of the dihedral. A simple method utilizing these guidelines is proposed to enhance the flattened dihedral performances. And an experimental validation of this design is finally proposed at 24 GHz.