A Metallic Miniaturized Log Periodic Dipole Array Antenna with Circular Polarization by 3D Printing

A sized-reduced log periodic dipole array antenna (LPDA) realizing circular polarization (CP) is presented. Based on the traditional LPDA principle, the crossed dipole, arranged by adding the auxiliary dipole to the inverse dipole orthogonally, is used to create the circular polarization. The proposed size-reduced CPLPKDA has 42% length reduction. The proposed antenna is fabricated by the 3D printed technology, which have advantages in the realizations of complex models. Selective laser melting (SLM), which uses aluminum alloy as material in this design, is used in fabrication. The gain of proposed antenna is 5.1 dBi over the 2.1-3.0 GHz impedance bandwidth in measurement. The proposed antenna has 73.7% impendence bandwidth (IBW) and 35.7% axial ratio bandwidth (ARBW). Radiation patterns agree well in simulation and measurement.