Perforated extensible 3-D hyperbolic secant lens antenna for directive antenna applications using additive manufacturing.

In this paper, a novel three-dimensional (3-D) generalized hyperbolic secant (H-S) lens is first introduced using perforated dielectric material. The attractiveness of this new lens is its unique intrinsic flat shape characteristic and extensibility for different configuration scenarios, which provide a potential alternative design for a planar Luneburg and half Maxwell fish-eye lens based on a complex conformal mapping method. A high gain and wideband printed antipodal fermi antenna as a feeding source is employed in the proposed lens antenna prototype. The high radiation performance with low side lobe level of the fabricated lens prototype is validated from 8.2GHz to 12.5GHz, demonstrating 23.8 dBi realized gain at 10 GHz with 3-dB beamwidth of 9° and 2-dB fractional gain bandwidth of 41.6%. Besides, the total radiation efficiency is above ∼40% across all tested frequencies, which suggests the proposed H-S lens itself has a broadband response. The simplicity and low-cost fabrication using additive manufacturing of its lens design indicates great potential in broadband high directive antenna applications.