We show that the cross Wigner function can be written in the form
W(ψ,ϕ)=S^(ψ⊗ϕ^) where
ϕ^ is the Fourier transform of
ϕ and
S^ is a metaplectic operator that projects onto a linear symplectomorphism
S consisting of a rotation along an ellipse in phase space (or in the time-frequency space). This formulation can be extended to generic Weyl symbols and yields an interesting fractional generalization of the Weyl-Wigner formalism. It also provides a suitable approach to study the Bopp phase space representation of quantum mechanics, familiar from deformation quantization. Using the "metaplectic formulation" of the Wigner transform we construct a complete set of intertwiners relating the Weyl and the Bopp pseudo-differential operators. This is an important result that allows us to prove the spectral and dynamical equivalence of the Schr\"odinger and the Bopp representations of quantum mechanics.