In this paper, a flexible composite broadband dipole antenna printed with silver nanoflakes is presented. The antenna is composed of two identically printed split-ring resonators surrounding each arm of a printed dipole element. Each arm of the dipole and the split-ring resonator to which it couples is printed on the top and bottom sides of a thin dielectric substrate to give the antenna its flexibility. The compact antenna has overall dimensions of 10 mm × 74.8 mm × 0.254 mm (0.063λ × 0.473λ × 0.0016λ at 1.9 GHz). The thin, flexible antenna produces stable, linearly polarized radiations in a broad bandwidth. Two antennas printed with copper and silver nanoflakes on a thin dielectric substrate were studied and their characteristics were compared. The printed antenna with copper cladding had a fractional bandwidth of 52.63%, peak gain of 2.14 dBi, and radiation efficiency of > 92%. The printed antenna with silver nanoflakes had a fractional bandwidth of 48.14%, peak gain of -0.78 dBi, and radiation efficiency of > 15% within the impedance bandwidth.
This work was supported in part by Institute for Information & Communications Technology Promotion (IITP) grant funded by the Korea government (MSIP) (No. 2017-0-00959, University ICT Basic Research Lab), in part by \u201cHuman Resources Program in Energy Technology\u201d of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea (No. 20164030201380).