Circularly polarized aperture-coupled circular microstrip patch antennas for L-band applications

Circularly polarized aperture-coupled circular microstrip patch antennas ar e investigated with the goal of obtaining an 8% impedance and ellipticity b andwidth in L-band, Three varieties-a single-feed patch with perturbation s egments, a single-feed stacked patch with perturbation segments, and a dual -feed patch with a 3-dB branch line coupler as an external polarizer are co nsidered to obtain the required performance. All the three investigated pat ch configurations meet the impedance bandwith requirement, but only two var ieties: the single-feed stacked patch and the dual-feed patch meet the requ ired ellipticity bandwidth. These antennas feature more than 9-dBi gain, Th ey use low-cost substrates and foam for bandwidth enhancement and, hence, t hey are attractive for applications where the production cost is of importa nce.