Semi-Additive Manufacturing for Broadband Conical Inductors

This paper presents a semi-additive manufacturing process for broadband conical inductors with high design freedom. Several conical inductor designs are investigated, fabricated, and measured in a shunt configuration. The conical inductors operate over a frequency range up to 125 GHz. The deviation between measured and simulated inductance does not exceed 18.5 %, while inductance values of up to 9 nH are demonstrated. The maximum DC resistance per unit wire length remains below 0.021Ω/mm. This work demonstrates the potential of semi-additive manufacturing for inductors, especially for biasing applications. It stands out due to its excellent high-frequency performance, easy assembly process, and low DC resistance, resulting in a higher quality factor and improved current carrying capability compared to previous reported additively manufactured inductors. Furthermore, the developed approach provides high design flexibility and tailoring of the inductor properties to specific application requirements.