Additive Manufacturing for Advanced Microwave and RF Applications

Additive approaches have been motivated by the need for rapid prototyping and systems that are flexible, lightweight, conformable, and wearable. There is growing need to adopt Additive Manufacturing (AM) technologies for Radio Frequency (RF)/Microwave (MW) electronics motivated by the need for rapid prototyping and the production of RF systems that are flexible, lightweight, conformable, and wearable. Printing RF electronics for DoD applications (e.g., radars, communication systems) is challenging since the requisite materials, components and systems demand higher performance than required for low frequency applications. Materials play a critical role in the application of AM to RF and MW applications. Development and characterization of low-loss dielectrics, ferroelectric inks, and convertible inks are essential in printing devices that will provide desired performance metrics. The formulation of new materials, including UV curable dielectric, resistive, and ferroelectric inks, and characterization of their properties at microwave frequencies, are key challenges in applying additive manufacturing to printed RF and microwave devices.Details of these challenges and ways of mitigating them through specific applications, which exemplify all stages of development, will be presented. Details of the key enablers for these applications and devices will also be described. Recently, there has also been interest in applying Additive Manufacturing (AM) in packaging of microelectronic devices. Additive packaging offers advantages of expanded functionality in restricted volume, through miniature, low-SWaP-C sensors, allowing for non-traditional form factors. In this presentation examples of additive packaging including, design, fabrication, and characterization of a non-planar multi-material MMIC structure as well as bare-die integration is presented to demonstrate significant footprint reduction and circuit compaction. The results of this work show that fully additive approach is feasible for non-planar circuits, which will allow for footprint reduction, weight reduction, and achievement of novel form factors that are critical for microwave applications.Finally, describe several printed devices and subsystems, including tunable Frequency Selective Surface (FSS) based filters, wearable metasurface filters, and printed connectors will be provided. Our work includes multi-physics-based design and modeling as well as the development of printing/processing technologies using various direct-write printers for these applications.