A 3D Printed Elliptical Mirror for Material Characterization Using FMCW Transceivers

Elliptical mirrors can be used to focus electromagnetic waves without losses that occur during propagation through dielectric lenses. As common milled mirrors have a high weight and require time-consuming productions steps, a 3D printed elliptical mirror, coated with a copper spray, is analyzed in this paper regarding its suitability for microwave applications. It can be shown that both mirrors can reach focus diameters below 1 cm, which is suitable for applications like material charakterization. Additionally, this paper presents radar measurement results at 145 GHz that compares the 3D printed mirror with a common milled one.