Advanced Manufacturing and Characterization of mm-Wave Two-Layer Reflectarray Cells

Reflectarray antennas (RA) have been proven as a transformational technology for a variety of applications, including space missions, where flat antenna reflectors are engineered with a great degree of freedom on operational bands and beam shapes. RA also offer the ability of using deployable flat geometries which are highly desirable for CubeSat missions. On the other hand, additive manufacturing processes have evolved over the last decade to achieve overall antenna performance and feature sizes that enable their operation for mm-wave frequencies. In this paper, dual-band RA elements are designed for the 18-32 GHz frequency band. The multilayer elements are fabricated using direct digital manufacturing, combining fused deposition modeling of polycarbonate (PC) and micro-dispensing of Ag ink, with an intermediate step of milling to enhance the surface roughness. The phase response of the elements is measured using WR-34 waveguides, and the geometry is inspected using X-Ray CT scanning.