Electrically Tilted Broadband Antenna using Negative Refractive Index material

A negative refractive index material loaded wideband patch resonator is presented for the wireless applications. The negative refraction has been achieved by creating a semi-circular and linear defect in the antenna ground plane. The antenna demonstrates an electrical tilt. This presents the ability to keep the communication module mechanically vertical. The engineered metallic strip excites the resonance mode. The structure of the metallic strip is a modification of thin wire and split-ring resonator (SRR) which are responsible for negative values of permeability and permittivity respectively. The finite truncated ground plane significantly helps to improve the antenna bandwidth. The antenna has an electrical length of $0.65\lambda \times 0.65\lambda$ where $\lambda$ is the wavelength at lowest resonance. The resonating frequencies of antenna are 2.46, 3.5, and 5.5 GigaHertz, respectively. The antenna has impedance bandwidth of 8.94%, 14.57% and 8.72% for the presented center frequencies respectively. The antenna prototype was fabricated where measured and simulated results show good correlation.