Size reduction of compact dual-band antenna based on metamaterials

A compact dual-band antenna based on metamaterials with emphasizing in size reduction is proposed in this paper. The proposed antenna that takes a U-shaped patch is designed to operate in dual frequency bands of WiMAX, 2.3GHz and 3.3GHz. In the design, metamaterials with composite right-left handed transmission line approach is used to implement the proposed antenna. The antenna is fed by use of microstrip line feeding technique and deployed on FR-4 Epoxy substrate with the relative permittivity of 4.3 and the thickness of 0.8mm. To demonstrate the size reduction capability, the metamaterials-based antenna will be compared with other 2 microstrip antennas that resonate at the same resonant frequency, namely half ground plane antenna and full ground plane antenna. Here, the microstrip antennas are also deployed on similar dielectric substrate with the same relative permittivity. These 3 kind antennas are then compared each other in terms of physical size, return loss, bandwidth, gain, and radiation pattern. From the comparison, it is shown that the employment of metamaterials for antenna implementation is achieving the wider bandwidth for both frequency bands and the smaller antenna size up to 28% and 70% compared to the microstrip half ground plane and full ground plane antenna, respectively.