The demand for WIMAX technology isgoing to increase due to it significant characteristics of large bit rate withhigh speed and distance range in the field of telecommunications. In recentyears microstrip patch antennas have played a very important role in thetelecoms industry because of their unique characteristics of small size, lightweight low cost on mass production. They are easily etched on any PCB and willalso provide easy access for troubleshooting during design and development.They also have drawbacks as narrow bandwidth, low gain, small directivity andlow efficiency due to dielectric losses and conductor losses.
In order toovercome the drawbacks a based metamaterial antennas are suitable for thisapplication.These antennas are made of engineeringmaterials designed to have properties that are not found in nature. These metamatrialantennas are easy to fabricate and has small dimension. A square – shaped splitring resonator unit cell is shown in figure (2).Their shapes, size, geometry,orientation and arrangement gives them their unique properties capable ofmanipulating electromagnetic waves.
The unit cells are formed to replacethe SRR in other to produce negative permeability and LH ( left handed).Complementary split RingResonators generate an electric field from the flow of current through thetransmission line. These materials(Metamaterials) are fabricated fromassemblies of multiple elements fashioned from composite materials such as;metal and plastic.
They are usually arranged in repeating patterns at a scalethat are smaller than the wave lengths of the phenomena they influence. Sincethe introduction of this technique, a lot of researchers were interested ininvestigating these artificial materials.In this work the goal is tominiaturize size of antenna dimension and improve bandwidth. By comparingdimension and the parameters of the conventional microstrip patch antenna andantennas with square-shaped split ring metamaterial unit cells. Two rectangularmicrostrip patch antennas with square-shaped split ring metamaterial unit cellsare designed. Antenna A consists of a double 5X5 square-shaped split ringmetamaterial and antenna B composed with a single 5X5 square-shaped split ringmetamaterial. The designed metamaterial unit cells are loaded on the groundplane.
The presence of square-shaped split ring metamaterial unit cells in theproposed microstrip patch antennas are expected to improve the performance ofthe antennas, miniaturize antenna dimension, improve bandwidth than theconventional microstrip patch antenna and able to be applied in WIMAXtechnology.