Open Access3D‐printed 4‐zone Ka‐band Fresnel lens: design, fabrication, and measurement
Author(s) -
Jeong Kyoung Ho,
Ghalichechian Nima
Publication year - 2020
Publication title -
iet microwaves, antennas and propagation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.555
H-Index - 69
eISSN - 1751-8733
pISSN - 1751-8725
DOI - 10.1049/iet-map.2019.0117
Subject(s) - optics , lens (geology) , fresnel lens , materials science , focal length , fresnel zone antenna , zone plate , fresnel zone , fabrication , antenna (radio) , optoelectronics , dipole antenna , physics , electrical engineering , engineering , slot antenna , diffraction , medicine , alternative medicine , pathology
A planar and thin‐grooved Fresnel lens is a great candidate for gain enhancement in millimetre wave communication, imaging systems, and wireless power transfer applications. The authors report the design, fabrication, and measurement of a 3D‐printed Fresnel lens, using a single material. A low‐profile (1.2 λ thick) 4‐zone Fresnel lens with 16 annular rings is designed with a focal length of 40 mm (≃4 λ ) operating at 30 GHz. Authors’ design consists of four‐step heights with outer radius of 69 mm (6.9 λ ). Permittivity and loss tangent of polylactic acid are measured to be 2.79 and 0.0048 at 30 GHz, respectively. Focusing ability of the lens is studied using full‐wave simulation. The lens is fabricated using a table‐top commercial fused deposition modelling printer. The surface roughness, step heights, and radii of each zone are measured and verified using a 3D optical profilometer. Impact of the 3D‐printed limitation on performance of the device is discussed. The gain of the fabricated prototype is measured, in conjunction with a horn antenna, in an anechoic chamber. Pattern measurement results illustrate 6.6 dB gain enhancement at broadside at 30 GHz. Gain enhancing behaviour is studied at three different focal lengths and frequencies of 29–31 GHz.