Tri-Band Circularly Polarized Monopole Antenna for Wireless Communication Application

A circularly polarized (CP) CPW-fed (CoPlanar Waveguide) with two asymmetric U-shaped strips, patch antenna is described in this paper. The antenna consists of a radiating patch composed of a hexagonal-ring connected with two annular rings on the two corners, which provide wide CP. The CPW-fed antenna was constructed by etching out two L-shaped slots and adding two asymmetric U-shaped strips to the ground, which greatly enhanced both the impedance bandwidth (IBW) and axial ratio bandwidth (ARBW). The proposed antenna design yields a measured wide IBW = 5.637 GHz (4.484–10.121 GHz), which is about 80.53% with respect to the center frequency fc = 7.3 GHz. The simulated 3-dB axial ratio (AR) bandwidth for tri bands includes 95 MHz (1.37%), 186 MHz (2.35%) and 149 MHz (1.67%) resonating at 6.95, 7.93, and 8.91 GHz, respectively. The radiation characteristics of the implemented antenna have been analyzed and discussed in this paper. The maximum simulated peak gain is 5.968 dBi at 6.063 GHz. The proposed antenna can be suitable for C- and X-band wireless communication applications.