Co-planar waveguide (CPW) patch antenna with octagonal-shaped ring for WiMAX application
WiMAX (Worldwide Interoperability for Microwave Access) is a part of wireless communication standards based on the IEEE 802.16 set of standards. In this work, a co-planar waveguide (CPW) patch antenna with octagonal-shaped ring had been design for WiMAX application of 3.5 GHz. This proposed CPW antenna is using FR-4 substrate with dielectric constant, ε r = 4.4 and the electrical conductivity tangent loss, tan Δ = 0.019. There are three stages of the antenna design that consist the Design A - basic rectangular patch antenna, the Design B - rectangular patch antenna with octagonal-shaped ring while the last stage is Design C -rectangular patch antenna with octagonal-shaped ring with CPW effect. A parametric study of CPW length, LCPW had been done to make sure the best return loss performance and the location of the resonant frequency near to WiMAX frequency range. In this case, nine different dimensions of LCPW that considers is from 11 mm to 19 mm. It shows that the LCPW = 18 mm shows the resonant frequency of T 3.528 dB. The CPW patch antenna with octagonal-shaped ring effect a wider bandwidth and create two resonant frequencies. It shows that the proposed antenna covers from the 2.282 GHz to 4.216 GHz, with bandwidth of 1.978 GHz, improve from Design A and Design B of 0.11 GHz and 0.73 GHz, respectively. Two resonant frequencies are located at 2.59 GHz and 3.528 GHz with return loss of −23.89 dB and −34.78 dB, respectively. The antenna gain of Design C is improve to 2.92 dB, after the addition of the CPW technique.