A semiconductor device comprises a first semiconductor chip, a first planar waveguide transmission line arranged within a BEOL metal stack of the first semiconductor chip, wherein the first planar waveguide transmission line comprises line sections situated opposite one another, and a second planar waveguide transmission line arranged over the first semiconductor chip and electrically coupled to the first planar waveguide transmission line, wherein the second planar waveguide transmission line comprises line sections situated opposite one another.