Circular polarized dual-band antenna for WLAN/Wi-MAX application

A novel square ring printed antenna has been suggested for dual-band circular polarization (CP). The geometry contains a square patch and a square ring structure for dual-band operation. Circular polarization is achieved using triangular cut at the boundary and right angle bend with inner perturbation. The suggested antenna is excited from the lower layer through electromagnetic (EM) coupling technique. The antenna shows good impedance bandwidths of 90 MHz (2.43-2.52 GHz) and 800 MHz (5.7-6.5 GHz, respectively. The antenna shows 3 dB axial ratio bandwidth of 20 MHz at lower band and 120 MHz at upper band with improved gain>6 dBi. The simulated and measured results are well agreed with each other. The antenna is promising wideband operation at the upper band. This antenna was implemented on fiberglass reinforcement laminated Arlon substrate with dielectric constant ((r)=2.55), and the overall physical dimension of 30 x 30 x 3.048 mm(3). The designed antenna can be extensibly applicable in WLAN/Wi-MAX communication. The presented antenna is designed using hyperlynx IE3D and the simulated results are presented.