Design and implementation of I-slot conformal circular patch antenna on sphere structure

Abstract

In this article, an I-slot circular patch antenna conformed on a spherical structure is proposed. For the implementation of the proposed antenna, the polylactic acid (PLA) material is used with the help of a 3D printer. In accordance with this purpose, we determine the permittivity value of the PLA with a T-resonator method before the design process. Then, the geometrical design of the spherical patch antenna is optimized by means of a differential evolution algorithm. After the design and optimization process, the conformal spherical patch antenna is fabricated on a sphere cap. The main characteristics of the proposed antenna are given for both the simulations and the measurements. It is seen that the simulation results agree well with the measurement results. Furthermore, an experiment is performed in order to examine the application possibility of the presented spherical antenna. For this experiment, a spherical communication module with the proposed antenna and an inner wireless transmitter system is built. In this experiment, the spherical module is rolled down a slope while it continuously transmits pseudo-random numbers. The data are received by a receiver station at the top of the slope. The received data are evaluated in terms of the amount of received packets per unit of time. The numerical results indicate that the proposed antenna can be used for dynamic spherical systems such as throwable objects and spherical robots.