LAUSR

The paper presents three single fed circularly polarized square patch antenna structures for wireless communication applications. The antennas resonate from 1.5 to 1.8 GHz and can cover L-band GPS and GSM 1800 band. The antenna-1 consisting of four slits introduced at the boundary of radiating square patch with a cross slot in the centre. The antenna-2 exhibits four slits, a cross slot in the centre with radiating square patch protected using dielectric superstrate. A wider impedance bandwidth of 100 MHz is achieved with superstrate loading. Also, the antenna gain is improved up to a maximum level of 7 dB within the band of operation. Further, stacking of antenna-1 is done using conventional square patch as the parasitic element. The dual-band resonating antenna-3 is achieved with circular polarization in both of the frequency bands. The 3-dB axial ratio bandwidth is 1.1 % for the upper band and 1.3 % for the lower band. Proposed structures are fabricated on the FR-4 epoxy substrate and fed using SMA connector. The measured results are in good agreement with the simulated results.