2134/20447 Shiyu Zhang Shiyu Zhang J. C. Vardaxoglou J. C. Vardaxoglou William Whittow William Whittow Raj Mittra Raj Mittra 3D-printed flat lens for microwave applications Loughborough University 2016 Ray optics Flat lens Graded index lens 3D-printing Additive manufacturing Mechanical Engineering not elsewhere classified 2016-03-03 14:21:27 Conference contribution https://repository.lboro.ac.uk/articles/conference_contribution/3D-printed_flat_lens_for_microwave_applications/9558530 This paper presents the design of a 3D-printed flat graded-index lens based on ray optics. The lens is comprised of several concentric dielectric rings with bespoke relative permittivities for transforming spherical waves into plane waves. 3D-printing was used to fabricate this lens with graded and tailored dielectric properties in a single process. The 3D-printed flat lens is low-cost and light-weight, but provides broadband and high gain performance. Measurement results show that the realised gain of the lens is 8 to 10 dB over the frequency band ranging from 12 to 18 GHz.