Board-level rapid-prototyping shielding for radio frequency transmission lines

摘要

This paper presents an initial study of the effectiveness of additively manufactured electromagnetic shielding for microwave printed circuit boards (PCBs). In analog/radio frequency and digital designs it is uncommon to find a PCB without some form of an electromagnetic (EM) shield covering one of its components. Often these shields are constructed from machined metal housings or seal frame lids, which limit the application of the shielding to specific components or regions of the PCB. The proposed approach described in this paper implements additive manufacturing (AM) with a form of metal deposition to create conformal shields to increase coplanar waveguide to coplanar waveguide (CPW-to-CPW) isolation. The level of shielding obtained is shown to be comparable to CPW-to-stripline isolation from DC to 30 GHz for 33 mm traces separated by 3.8 mm.