An Agile Additively Manufactured 5G/mm-Wave RF Front-End With Multilayer Conformality and Printed RF VIAs for Ultrawideband and Miniaturized Systems

This article presents the first fully additively manufactured (AM) multilayered RF front-end (RF-FE) for mm-wave frequencies (20–30 GHz), integrating active devices, passive printed structures, and RF signals routed on both outer layers. The system features flexible inkjet- and screen-printed RF vertical interconnects (VIAs) with insertion loss between 0.58 and 1.64 dB and minimal bending-induced degradation. Its multilayer architecture enables significant miniaturization, ideal for compact, low-cost, and sustainable mm-wave modules in wearable devices, autonomous UAVs, and smart cities. The design achieves inkjet-printed feature sizes down to $60\,\mu $ m, critical for mm-wave filters, and incorporates a monopole antenna array with up to 9-dBi gain, demonstrating robust planar and conformal performance. Leveraging AM, this work establishes a pathway for miniaturized, flexible, and cost-effective RF systems, addressing key challenges in advanced communication and sensing applications.