CPW-Fed Double Circular Ring Slot Wideband Antenna for WLAN/WiMAX Applications

摘要

In this paper, a wideband coplanar waveguide (CPW)-fed double circular ring slot (DCRS) antenna is presented. This antenna consists of a DCRS with an extended ground plane to achieve wider impedance bandwidth and excited by a $50 Omega$ CPW feedline. A prototype is fabricated and the dimensions merely $0.306 imes 0.343 imes 0.015lambda^{3}_{L0}, lambda_{L0}$ is the wavelength in free space at the lowest operating frequency (i.e., 2.86 GHz). The measured impedance bandwidth is nearly similar to the simulated results is about 95.3 % (from 2.86 to 8.06 GHz) ($S_{11} < -10$ dB). Suitable combinations of an extended ground plane and a pair of circular ring slot on the rectangular patch, a wider impedance bandwidth is achieved. Simulated voltage standing wave ratio (VSWR) $< 2$ is achieved entire band of frequency operation. Meanwhile, the proposed antenna simulation radiation patterns result in an exhibit almost omnidirectional.