3D-printed λ/4 phase plate for broadband microwave applications

An efficient design for a quarter-wave (lambda/4) retardation plate (QWP) operating at microwave frequencies has been designed and manufactured using dual head fused deposition modelling (FDM) 3D printing. Exploiting a bespoke composite material feedstock filament with high dielectric permittivity epsilon(r) = 10.8, the resulting 3D-printed QWP comprising alternative layers of high and low permittivity had a high artificial double refraction of Delta epsilon = 2.9. The QWP provided broadband conversion of linear to circular polarization and phase modulation of an incident plane electromagnetic wave at 12-18 GHz, and demonstrated the potential for optical devices via additive manufacture for use in the microwave frequency range. Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License.