Broadband, electrically long vertical waveguideinterconnect

Design of a Non-Contact Vertical Transition for a 3d Mm-Wave Multi-Chip Module Based on Shielded Membrane Supported Interconnects

“…The high-performance vias which have been extensively demonstrated so far fall into two categories: electromagnetically coupled [25][26][27][28][29][30][31] with at best, 0.2 dB insertion loss at W-band [30] for a microstrip type geometry, and direct contact transitions [31][32][33][34][35] with around 0.6 dB insertion loss at 94 GHz [31] for a coplanar line. Both of these have been demonstrated only between lines fabricated on bulk dielectrics.…”

“…Since both upper and lower shielding would generally be required for each line in a 3D membrane-based MCM, this local variation in ground plane separation would be difficult to achieve using traditional fabrication techniques such as silicon micromachining. This means that their demonstration to date has only involved the coupling of unshielded coplanar lines with a common substrate [27,30], or microstrip lines with a common substrate [30] or ground plane [25,26,28,29,31] (Figure 1(b)), and this has until now The proposed 3D millimeter-wave MCM is similar in concept to that illustrated in Figure 1 but is fully compatible with the micromachined lines demonstrated in [1] and the vias characterized in Sections 3.1 and 3.2. The characterized vertical coupling structures allow the routing of millimeter-wave signals between the adjacent levels of a 3D module created by stacking self-aligning micromachined shielding and membrane layers.…”