A Novel Octal Annular Ring-Shaped Planar Monopole Antenna For WiFi And Unlicensed Ultra Wideband Frequency Range Applications

Our paper presents the design of a unique annular ring-shaped planar monopole antenna with octal geometry intended for a broad spectrum of frequency applications. Utilizing FR4 epoxy for the substrate and copper material for the top patch, the antenna measures 39 mm $\times$ 30 mm $\times$ 1.6 mm. It exhibits resonance at 6.8 GHz, with a return loss of -49.01 dB. The antenna demonstrates a broad frequency range from 2.1 GHz - 13.1 GHz, resulting in an overall -10 dB bandwidth of 11 GHz. At the resonating frequency of 6.8 GHz, the antenna accomplished a total gain of 3.01 dBi and a peak gain of 5.87 dBi at 12.4 GHz. Additionally, it attains a high radiation efficiency of 95.26%. The annular patch of the antenna helps distribute the current uniformly at the boundaries of the patch. This helps achieve better current distribution and wider -10 dB bandwidth. This antenna is a versatile replacement for multiple antennas catering to various frequency bands.