def METHOD_NAME(self):
    sinphi, cosphi = np.sin(self.phi), np.cos(self.phi)
    l = np.broadcast_to(1.0, self.shape)
    return {
        "rho": CartesianRepresentation(cosphi, sinphi, 0, copy=False),
        "phi": CartesianRepresentation(-sinphi, cosphi, 0, copy=False),
        "z": CartesianRepresentation(0, 0, l, unit=u.one, copy=False),
    }