Additively Manufactured Frequency Selective Structures on Curved Surfaces

Two different additive manufacturing methods are employed to pattern a curved plastic surface with a frequency selective structure (FSS). Here, a dielectric lens is used as a proof of concept for a curved surface and the FSS is a bandstop filter designed to operate near 150 GHz. An aerosol jet printing process is used to directly print the FSS onto a planar surface and a lens structure. Additionally, a patterned FSS is demonstrated by printing the test structures with the pattern pre-inset into the dielectric, sputtering them with copper, and then selectively removing the copper from the unpatterned area. This procedure is also known as a damascene-like process. Structures are printed using a Formlabs Form 2 printer, which uses a stereolithography (SLA) technology, and a clear colored high temperature curing resin as the build material. Simulations are performed using ANSYS HFSS and measurements were taken using an Emcore frequency domain THz system.