Simple Wideband Circularly Polarized Tightly Coupled Dipole Array

This letter introduces a novel circularly polarized tightly coupled dipole array (CP-TCDA). The proposed array employs the TCDA concept of overlapping dipoles on a shallow ground plane to achieve wide bandwidth. In addition, for the first time, a CP-TCDA is realized. The antenna element is comprised of a set of orthogonal dipoles connected through two intrinsic quadrature phase shifters. The overlapping dipoles are realized via capacitive pads that cross the dipole edges and printed on the other side of the substrate. The feed employs a meandered Klopfenstein vertical balun to provide 50 $\Omega$ to 188 $\Omega$ balanced port impedance matching. For verification, a finite (10 × 10) CP-TCDA is fabricated and measured to validate the antenna performance. Testifying was done using a stochastic model-based ultrawideband 8 × 8 corporate power divider. The designed CP-TCDA provided an impedance bandwidth of voltage standing wave ratio (VSWR) $< $ 3 from 2.3 to 7.5 GHz, and an axial ratio of $< $ 3 dB from 2.7 to 5.4 GHz.