Design of 3D-Printed Lens for Ultra-Wideband Flower-Shaped Stub Antenna

The design of 3D-printed lens for ultra-wideband (UWB) slot antenna with flower-shaped stub is presented. This research presents four types of lenses with different shapes i.e., cone lens, semicircle lens, Fresnel lens and hemispherical lens that are mounted on an UWB planar antenna. The effect of these lenses on reflection coefficient, gain, and radiation pattern is proposed. The simulation results show that all four lenses, which are combined with an UWB planar antenna. The operating band of the designed antenna starts at 3.1 GHz to 10.6 GHz. Moreover, using these lenses, the antenna characteristics, e.g., antenna gain, and antenna radiation patterns are enhanced. The average gain at zero degree of the antenna without a lens is 1.94 dBi, while the average gain at the same angle of the antenna with four types of lenses are increased more than 1.1 dBi. Four shaped of the lens, e.g., cone, semicircle, Fresnel, and hemispherical, are selected to modify the gain and radiation pattern of UWB flower-shaped stub antenna. After implement the lens, the gains of the antenna at zero degree are increased to 3.09 dBi, 3.35 dBi, 3.72 dBi, and 5.07 dBi, respectively. In addition, the radiation pattern of the antenna without an additive lens is bi-directional pattern, but when adding a lens, the radiation pattern changes to a unidirectional one. It is found that a hemispherical lens is a good choice for the proposed antenna because it has a higher gain than other lenses. Furthermore, this study is useful for lens selection to enhance UWB antenna performance.