Substrate-free patch antenna array realized by metallic 3-D printing

A substrate-free low profile patch antenna array is the subject of discussion in this paper. The objective is to transform the traditional microstrip antennas whose metallic circuit lines and patches are etched on Printed Circuit Boards (PCB), whereas the proposed structure does not have the need for PCB while retaining all the good features of patch antenna array. This effectively gets rid of any dielectric loss, aiding to achieve higher efficiency and consequently higher gain. A 3-D printing technique is adopted in this work to realize this unique structure. Results show that the substrate-free patch antenna array can operate with a bandwidth of about 35%. Gain is better than 12dBi in the entire band and a 15dBi gain is achieved at the center frequency.