Three-dimensional printed asymmetric biconical antenna for borehole concrete sensing application

Abstract

An asymmetric biconical antenna is proposed to be used for a borehole radar system to inspect the corrosion of reinforcing bar inside a concrete structure. First, the antenna is designed by considering the hole needed for the borehole diameter. Then, the antenna is fabricated using a three-dimensional printer with polylactic acid plastic and coated with copper tape. Finally, the antenna is tested in free space and concrete environment. The diameter of the antenna is 20 mm and a length of 34 mm, with the usable frequency in free space is 2.4 GHz (2.1 GHz in concrete) to 8 GHz.