Embodiments may relate to a semiconductor package that includes a package substrate coupled with a die. The package may further include a waveguide coupled with the first package substrate. The waveguide may include two or more layers of a dielectric material with a waveguide channel positioned between two layers of the two or more layers of the dielectric material. The waveguide channel may convey an electromagnetic signal with a frequency greater than 30 gigahertz (GHz). Other embodiments may be described or claimed.