An improved design and implementation of a broadband and wide axial ratio beamwidth circularly polarized parallel plate antenna

This paper presents an improved design and implementation of broadband circularly polarized (CP) antenna that features a broad bandwidth and wide axial ratio (AR) beamwidth. First, the relationship between the three parallel plates (rectangular, semicircular, and semielliptical) and theta is analyzed. The semielliptical parallel plates (PP) used to obtain a wider 3dB AR-beamwidth (104 degrees x 110 degrees x 102 degrees x 118 degrees at phi = 0 degrees, 45 degrees, 90 degrees, 135 degrees, respectively) compared with rectangular and semicircular PP. Secondly, orthogonal crosses with 43 degrees inclined are used to generate orthogonal fields, and broadband characteristics can be obtained by adjusting the arm of orthogonal crosses. The semielliptical CP-PP antenna prototype was verified by ANSYS HFSS simulation. According to the measurement results, the -10dB return loss is about 20% (24.3-29.7GHz). A gain of 9.22dBic at 27GHz and a 3dB AR-beamwidth of 106 degrees x 105 degrees at phi = 0 degrees and phi = 90 degrees are obtained. The designed semielliptical CP-PP antenna can be more beneficial to 5G millimeter wave applications.