Flexible Ink-printable Wideband Log-periodic Dipole Array Antenna for Millimeter-wave Applications

This paper presents a novel flexible ink-printable log-periodic wideband dipole array (LPDA) antenna for millimeter-wave applications. The antenna is fed by microstrip line through a wideband microstrip-to-coplanar stripline (CPS) balun. The antenna gain enhancement is achieved by adding three directors of decreasing length, based on the principle of Yagi-Uda antenna. The antenna gain remains ≥ 9.74 dBi over the whole operating frequency range of 23-28.5 GHz. The 10-dB bandwidth of the antenna is 21.8%, covering desired frequencies of 24.5 GHz and 28 GHz