3-D Printing and CNC Machining Technologies for Exploration of Circularly Polarized Patch Antenna With Enhanced Gain

This paper presents a gain-enhanced circularly polarized (CP) patch antenna, where 3-D printing and computer numerical control machining technologies are employed for the fabrication of its dielectric and metal parts, respectively. In order to assemble the whole structure effectively and accurately, a hybrid strategy and pin-loaded example are here proposed to deal with the detached dielectric and metal. On the one hand, asymmetrically 3-D printed substrate with the mesh-grid architecture is formed with resin chunks to introduce the perturbation and produce the CP radiation. On the other hand, its metal part likewise possesses the 3-D structure with four metal screws to be symmetrically placed in the two diagonals of square patch, thus making the patch and ground as a whole. More importantly, the screws have dual functions, which can not only integrate the dielectric and metal parts, but also work as shorting pins. Therefore, due to the shunt inductive effect of shorting pins, the dominant mode of patch is excited at higher frequency, resulting in the enlarged antenna area and enhanced gain. As a result, the gain-enhanced CP patch antenna is realized, and an antenna prototype is then fabricated and tested, exhibiting a high CP gain of about 10 dBic.