Compact Series-fed Circularly-polarized Patch Array based on Microstrip Line

A compact single -layer circularly polarized (CP) antenna array is proposed in this paper for 5G/6G applications. The conventional microstrip line is modified as a feeding network by periodically and alternatively loading field blocking stubs, producing a linearly polarized in -phase radiative field aperture. By adding CP corner -truncated patches beside these in -phase fields, a linear high -gain CP antenna array excited by a single feed is obtained. The feasibility of the proposed design is demonstrated through the fabrication and measurement of a 16 -element linear array. The results indicate that the 3 dB axial ratio bandwidth is 3.5% (19.60 similar to 20.30 GHz), the -10 dB impedance bandwidth totally covers the 3 dB axial ratio bandwidth, and the peak realized gain is 14.9 dBi under an antenna length of 5.692,0. This proposed strategy provides a very compact antenna structure to achieve high -gain CP radiation without the requirement of impedance transformers, phase shifters, and open -stop -band suppressing measures. Moreover, the antenna has a per -unit -length CP gain of 5.5/2,0, which is superior to many single -layer high -gain CP antennas.