A Size-Reduced, Circularly Polarized, Log-Periodic Dipole Array

Abstract

A single-feed, circularly polarized, log periodic dipole array (CPLPDA) with size-reduced, cross-dipole elements is proposed. Size reduction in elements is achieved with curved T-shaped, top loading. Compared to the full-sized CPLPDA elements, the achieved element-length reduction is 50%. With six elements, the antenna shows a -10-dB impedance bandwidth (IBW) of 87.0%, and a 3-dB axial ratio bandwidth (ARBW) of 50.0% in measurement. The common bandwidth (CBW) between the -10-dB IBW and 3-dB ARBW of the CPLPDA is 50.0%. The peak realized gain in the direction of the shortest element is 6.60 dBi over the CBW.