Ultrabroadband All-Dielectric Transmitarray Designing Based on Genetic Algorithm Optimization and 3-D Print Technology

An ultra broadband all-dielectric transmitarray antenna (TA) is designed based on genetic algorithm optimization (GAO) and 3-D print fabrication technology. The array element is composed of all-dielectric pillars with different sizes distributed on the two sides of a substrate. The element is operating in the out-of-band resonance (OBR) zone, whose transmission amplitude is nearly one and the phase can be easily controlled. Afterward, the geometric parameters of the elements on different positions of the TA surface were optimized using generalized Snell's Law-based GAO, which achieved broadband phase compensation and good transmission performance. As the structure is all- dielectric, it can be easily manufactured using 3-D printing technology. The TA was fed by a ridged horn, and the antenna gains are enhanced by 7-12 dB in the measuring band (9-20 GHz). Moreover, the 1 dB steady gain ranges from 14.5 to 20 GHz (up to 29%).