Frequency tuning of microwave filter at 60 GHz by laser ablation

摘要

The transfer characteristic of microwave filters realized as microstrip circuits is depending on geometrical properties of the structured conducting layers as well as on the material properties of the used substrate. Due to variations of material properties and manufacturing tolerances a certain deviation of target to realized transfer function has to be tolerated. In this article a method for the subsequent tuning of filter characteristics using an excimer laser is presented. By laser ablation of the metal thin film layer, material removal with a minimum size in the range of 5 μm is achieved.