Wideband Compact Circularly Polarized Sequentially Rotated Array Antenna With Sequential-Phase Feed Network

This manuscript elaborates a novel technique to achieve wideband 2 x 2 sequential-phase (SP) fed circularly polarized corner-truncated patch array antenna (CPCTPAA) with sequentially rotated elements. The presented design is printed on FR4 substrate and is fed through a SP feed network. This feeding mechanism is composed of a section of 270 degrees with four strips and a rectangular excrescence. Through the proposed approach, stable phase difference is generated at the end of the strips yielding in the CP feature. Each array element is composed of a corner-truncated square patch in opposite corners on the top side of the substrate. U-shaped slots are embedded on the ground plane with the aim of bandwidth enhancement. Moreover, rectangular slots are created at the crossing points of patches and feedlines to further enhance CPCTPAA performance. Simulation and measurement studies are conducted on a 70 x 70 x 1.6 mm(3) prototype to assess validity of the proposed design. The obtained results are reflected in terms of impedance bandwidth at 5.1-8.9 GHz for S-11<-10 dB and CP at 5.15-7.9 GHz for axial ratio < 3 dB. Besides, peak gain of 11.3 dBic is measured over the operating frequency range. These merits corroborate the proposed design as a promising choice in communication applications.