3D-printed planar graded index lenses

The authors introduce two flat graded-index (GRIN) lens designs in this study. First of these is a thick lens, which was designed and fabricated by using the three-dimensional (3D)-printing technique. Second, a thin dial-a-dielectric (DaD) lens, which uses state-of-the-art artificially engineered dielectric materials for design and for which they present only the simulated results, with plans to fabricate it in the future. Both designs overcome the difficulties faced in finding desired commercial off-the-shelf materials, either for 3D-printing or for fabricating conventional GRIN lenses. The lenses comprise of several concentric dielectric rings with bespoke relative permittivities for transforming spherical waves into plane waves and vice versa. The 3D-printed thick flat lens is low-cost and light-weight, but provides broadband and high gain performance. Measurement results show that the realised gain of the thick lens is 9–11 dB over the frequency band of 12–18 GHz. The designed DaD lens has the desirable characteristics of low loss, low reflection and broadband properties.

[1]  Raj Mittra,et al.  Flat Lens Design Using Artificially Engineered Materials , 2016 .

[2]  G. Hu,et al.  Experimental study for metamaterials based on dielectric resonators and wire frame , 2008 .

[3]  J. C. Vardaxoglou,et al.  Simulation Methodology for Synthesis of Antenna Substrates With Microscale Inclusions , 2012, IEEE Transactions on Antennas and Propagation.

[4]  T. Cui,et al.  Three-dimensional broadband and high-directivity lens antenna made of metamaterials , 2011 .

[5]  H. Ma,et al.  Three-Dimensional Gradient-Index Materials and Their Applications in Microwave Lens Antennas , 2013, IEEE Transactions on Antennas and Propagation.

[6]  Giorgio Savini,et al.  A new artificial material approach for flat THz frequency lenses. , 2012, Optics express.

[7]  C. Holloway,et al.  A double negative (DNG) composite medium composed of magnetodielectric spherical particles embedded in a matrix , 2003 .

[8]  T. Cui,et al.  Layered high-gain lens antennas via discrete optical transformation , 2008 .

[9]  Yang Hao,et al.  Flat Luneburg Lens via Transformation Optics for Directive Antenna Applications , 2014, IEEE Transactions on Antennas and Propagation.

[10]  William G. Whittow,et al.  Novel 3D printed synthetic dielectric substrates , 2015 .

[11]  A. Petosa,et al.  Design and performance of a perforated dielectric fresnel lens , 2003 .

[12]  W. Weir.  Automatic measurement of complex dielectric constant and permeability at microwave frequencies , 1974 .

[13]  Raj Mittra,et al.  Flat-Lens Design Using Field Transformation and Its Comparison With Those Based on Transformation Optics and Ray Optics , 2013, IEEE Antennas and Wireless Propagation Letters.

[14]  M. R. Chaharmir,et al.  A Wideband Transmitarray Using Dual-Resonant Double Square Rings , 2010, IEEE Transactions on Antennas and Propagation.

[15]  Yang Hao,et al.  Transformation optics for antennas: why limit the bandwidth with metamaterials? , 2013, Scientific Reports.

[16]  Sia Nemat-Nasser,et al.  Free-space microwave focusing by a negative-index gradient lens , 2006 .

[17]  Raj Mittra,et al.  On the Synthesis of a Flat Lens using a Wideband Low-Reflection Gradient-Index Metamaterial , 2011 .

[18]  Y. Hao,et al.  A broadband zone plate lens from transformation optics. , 2011, Optics express.

[19]  D. Smith,et al.  Gradient index metamaterials. , 2005, Physical review. E, Statistical, nonlinear, and soft matter physics.