Simple Wideband Circularly Polarized Tightly Coupled Dipole Array

This letter introduces a novel circularly polarizedtightly 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 50Ω to 188Ω 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 ultra-wideband 8×8 corporate power divider. The designed CPTCDA provided an impedance bandwidth of VSWR < 3 from 2.3 GHz to 7.5 GHz, and axial ratio of < 3 dB from 2.7 GHz to 5.4 GHz.