Hybrid 3d integrated circuits at millimeter-wave frequencies — advantages and trends

f  The implementation of passive rf functions is usually done by means of coplanar waveguides at mm-wave frequencies. We propose original solutions for improving their reliability, by integrating the parasitic mode filters as dielectric bridges through a 3D integration approach. Furthermore, original compensating methods are proposed in order to control the cut-off frequencies induced by the bounding networks. The 3D hybrid approach can also be efficiently used so as to accommodate the association between active, passive and radiating components. The 3D-CPW technology is therefore completed with Thin Film MicroStrip configurations (tfms), while composite ceramic/foam architectures become thinkable for radiating arrays.