Here is the abstract you requested from the IMAPS_2013 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|A Switched-Line Microwave Phase Shifter Fabricated with Additive Manufacturing|
|Keywords: Additive Manufacturing, Microwave Phase Shifter, Material Characterization|
|Additive manufacturing, also known as 3D printing, offers several important advantages over conventional planar fabrication methods for RF/microwave circuit design. The ability to print in 3D provides a convenient means of utilizing the volume of a structure to miniaturize circuit size and improve RF performance. For example, antennas can be integrated directly into the surface of a 3D package that is built around an electronic system in one solid piece. Such an approach can yield lighter weight packages with greater strength and stability, as opposed to assembling multiple planar objects into the 3D shape. The 3D printing capability also can allow for high frequency circuitry to be conformed to an arbitrary shape while maintaining performance and reliability. Recent advancements in printing low loss materials with additive manufacturing techniques have pushed performance levels even further. The purpose of this work was to investigate the RF properties of a 3D printed material, ULTEM™, and demonstrate a switched-line microwave phase shifter using the material. Additionally, this work also focused on the ability to integrate multiple materials, ULTEM™ and silver, into a single 3D printing process. Ring resonators using multiple combinations of substrates and superstrates (Rogers 4003C, FR4 and ULTEM™) were first characterized experimentally in order to extract the permittivity and loss tangent of the materials, and also to determine the conductivity of the printed silver conductors. Full-wave numerical electromagnetic simulations and equivalent circuit modeling were used in the initial design phase and for material property extraction from the measurement data. The ULTEM™ substrates were printed using the Stratasys Fused Deposition Modeling (FDM) 3D printer and the silver controlled impedance lines were patterned using nScrypt’s model 3D 450 direct print additive manufacturing printer. At 2.1 GHz, the extracted permittivity and loss tangent of the ULTEM™ was 3.1 and 0.008, respectively. The 4-bit microwave phase shifter was built using printed Ag lines on ULTEM™ and designed for 22.5°/45°/90°/180° phase shift at 6 GHz. The circuit includes Hittite GaAs MMIC switches and multiple discrete passives in the bias networks that were mounted using pick-and-place to the printed circuit. The performance of the ULTEM™-based designs is compared to designs on Rogers 4003C substrates using copper and printed silver interconnects.|
University of South Florida