Meander Line Coupled Cavity-Backed Slot Antenna for Broadband Circular Polarization

A Meander lines coupled cavity-backed slot antenna with broadband circularly polarized (CP) property is investigated. The proposed antenna comprises four meander lines, a cavity, and a sequential rotation feed network. By connecting ground planes of the patch substrate and the feed substrate with the slot cavity leads to resonant frequency at low band. The validity of the antenna´s performances is verified with a fabricated prototype. Measured results show that the designed antenna can yield 10-dB return-loss bandwidth of 40% (1.8 to 2.7 GHz), 3-dB axial-ratio (AR) bandwidth of about 34.04% (1.95 to 2.75 GHz), and 3-dB gain bandwidth of about 35.29% (2.1-3 GHz) with the maximum gain 5.15dBi. The antenna without cavity is also discussed.