This paper introduces multilayered cross-guide crosss-slot directional coupler designs in substrate-integrated waveguide (SIW) technology. Interface ports are modeled by dielectric-filled waveguides which allow for a higher dynamic range in scattering parameters than conventionally used microstrip-to-SIW transitions. It is demonstrated that in double-or triple-layered configurations, coupling values between 10 dB and 25 dB can be achieved over almost an entire waveguide band. Several Ka-band double- or triple-layered cross-guide coupler designs are presented using an Ansoft’s HFSS design environment. CST’s Microwave Studio is used for performance verification. © 2009 EuMA.