Design of a via-less, compact CPW-fed ZOR Antenna for WLAN Applications

A single layer, low profile, compact metamaterial zeroth-order resonator (ZOR) antenna has been proposed in this paper. A composite right/left-handed (CRLH) transmission line structure that is comprised of a single unit cell makes up the complete antenna. The design complexity of the proposed antenna is very low, since it does not involve any vias. A symmetric co-planar waveguide (CPW) structure is chosen to have design flexibility and to satisfy the design constraints. The main aim of incorporating the left handed behaviour into the design is to achieve compactness. The resonant frequency of zeroth-order mode is around 5.8GHz. A prototype of the proposed antenna has been fabricated and it has the dimensions of 0.348 lambda o x 0.309 lambda o 0.033 lambda o. The simulated peak gain of the antenna is found to be 0.65dBi. A significant amount of size reduction is observed in the patch area of proposed structure when compared to a regular patch antenna operating at the same frequency. The metamaterial behaviour has been verified with the help of dispersion diagram and vector electric field plot. Simulation is done so as to plot the reflection coefficient of the presented CPW ZOR antenna and it is also observed on the vector network analyzer (VNA). Simulation results show that the proposed ZOR antenna achieves -10dB impedance bandwidth of 7.76% and has a radiation efficiency of about 81.27% at the ZOR mode.