Small circularly polarised patch antenna

A small circularly polarised microstrip patch antenna, designed by cutting slots and adding tails, is proposed. The antenna is operated at 2.492 GHz and is built by using a microwave substrate of dielectric constant 3.367 with a coaxial probe feed. The impedance bandwidth (SWR < 2) is 1.61% and the axial ratio bandwidth is 0.381%. The measured gain is 4.6 dBi. The total area of reduction is about 50% in comparison with a square patch antenna without any slots or tails.