The fast development of drones, miniaturization of broadband solid-state amplifiers, mixers, and software defined digital hardware increase the demand for compact RF and microwave systems at lower cost, light weight, easy integration and fabrication. This thesis researches the feasibility of using additive manufacturing (ADM) to suit those requirements, moreover to improve the performance of microwave components. ADM not only simplifies the complexity of fabrication at a lower cost and weight, but also offers the ability to modify, re-print, and test parts on the fly; devices can be customized for a particular application and/or space. In addition, the versatility of 3D printing technologies to manipulate raw materials at a substructure level translates into the potential to improve device performance.
This study starts with a comprehensive analysis of a double ridged horn fabricated using different 3D printing technologies, metallization methods, and metal thickness compared to its metal counterpart to verify functionality, check limitations and understand the advantages and disadvantages of each technology. The power handling capability of the 3D printed broadband horn antennas is also tested by applying up to 100W continuous wave (CW) input signals. Results indicate similar electrical performance for the 3D printed devices.
The design of a low loss, high power, and broadband Rotman lens system and a horn/waveguide embedded into a UAV wing are investigated as a step to 3D print more complex, all passive electromagnetic structures that can be integrated into expendable systems. Measurements show repeatability, good electrical performance for all 3D printed components with a three-fold reduction in weight and an estimated ten-fold reduction in costs.
The focus of this research is to show that the flexibility of 3D printing offers the ability not only to fabricate microwave components but also improve the overall performance of the devices and system integration. Therefore, 3D printing is used to engineer gradient index (GRIN) structures to improve the far-field performance of horn antennas. The analysis, design and measurements of GRIN dielectric lenses to increase directivity and GRIN dielectric loadings to reduce side lobe levels with minimum gain reduction and mismatch losses are presented. A monolithic fabrication of the GRIN loaded horn with plating on the exterior is also investigated. Measurements show good agreement with simulated results.
This thesis demonstrates that ADM produces accurate and functional microwave components comparable to their metal counterparts, and is able to fabricate complex structures and improve performance at no additional cost. Moreover, this thesis also determines that ADM offers easy integration, on-demand manufacturing reducing the overhead of spare parts, and is well suited for high power applications. This work paves the way for new design possibilities that can fulfill the ever-changing demands of emerging systems. ADM’s benefits outweigh the drawbacks and the rapid development of new materials and increased accuracy of 3D printing technologies will soon provide new possibilities and overcome some of the current challenges.