Circulary polarized single-fed microstrip patch for wireless communications

For more than 25 years the circulary polarized single-fed microstrip patch is considered to be extremely narrow-band. The performances reported are almost exclusively related to single-patches printed on a dielectric substrate, which partially explains the frequency characteristics. The proposed antenna is a variation of the almost square patch and exhibits a theoretical axial ratio of less than 2.5 dB over a 10 percent bandwidth. The antenna was designed for PCN and PCS applications.