Rhombic arrangement of low-profile broadband circularly polarized magneto-electric dipole antenna array

This paper presents a broadband magneto-electric dipole (MED) circularly polarized (CP) microstrip antenna array with continuous rotating feed (SRF). The antenna element consists of a quarter-circle ring with irregular cross slits and a rectangular patch. The energy is combined with four metallized perforations and then transmitted to the radiating block to better excite the magnetic dipole-electric dipole energy and expand the bandwidth. Then, a 2 x 2 subarray was designed to further increase the axial ratio(AR) bandwidth. Finally, a 4 x 4 circularly polarized array arranged in a diamond shape is designed to utilize sequential rotating feeds to further improve the gain for millimeter-wave applications. Simulation results show that the impedance bandwidth (IBW) of the proposed array is 54.5% (20-35 GHz), and AR bandwidth of 3 dB is 27.2% (22.2-29.2 GHz), and the maximum gain is 16 dBic.