Data for: Fused filament fabrication of functionally graded polymer composites with variable relative permittivity for microwave devices

Fused filament fabrication (FFF) is a continuously growing additive manufacturing technology that aside from physical prototypes can also deliver functional prototypes and devices for radiofrequency (RF) and microwave applications. The very recent introduction of high-permittivity filaments for FFF has been one of the main facilitators for this major advancement, aiding microwave engineers to realise academics concepts that have thus far been impossible to fabricate and therefore invent new designs. However, the value to the RF community of these devices depends on accurate knowledge and repeatability of the electromagnetic properties of the materials being used which strongly relies on the processing strategy used during printing. This paper investigates the use of a high-permittivity filament and studies the impact of layer height and infill density on the relative permittivity (εr) and loss tangent (tanδ). A maximum relative permittivity of εr = 9.63 ± 0.16 and tanδ = 0.003 ± 0.0003 was achieved with a 200 μm layer thickness and 100% infill density. Finally, the results of this study are used in designing, simulating, 3D printing and measuring the performance of a novel graded-index dielectric lens operating at 10 GHz.

融合丝材制造（FFF）作为一种持续发展的增材制造技术，不仅能够产出物理原型，还能提供适用于射频（RF）和微波应用的实用原型与设备。近期，高介电常数丝材的引入成为推动此项重大进步的主要助力之一，帮助微波工程师将迄今为止难以实现的理论学术概念转化为实体，并因此创新出新的设计。然而，这些设备对射频领域的价值取决于对所用材料电磁特性的准确认知及可重复性，而这在很大程度上依赖于打印过程中的处理策略。本文探讨了高介电常数丝材的应用，并研究了层高和填充密度对相对介电常数（εr）和损耗角正切（tanδ）的影响。通过200微米层厚和100%填充密度，实现了最大相对介电常数εr = 9.63 ± 0.16和损耗角正切tanδ = 0.003 ± 0.0003。最终，本研究的结果被用于设计、仿真、3D打印以及测量一款新型梯度折射率介质透镜在10 GHz频段的工作性能。