Symmetric Circular-Shaped Multiband Hybrid Fractal Antenna using TLBO Approach: Design and Measurement

Abstract

In today’s world, wireless communication is considered as one of the most vibrant technological areas as it provides remote monitoring and control without using cabling and wiring setup. This paper describes the multiband behavior of several circular-shaped hybrid fractal antennas. Initially, a circular-shaped fractal antenna (antenna-A) is designed and its performance is scrutinized. Afterwards, hybrid fractal approach is utilized in the design process to enhance the operational performance and the resultant structure is named as circular-shaped hybrid fractal antenna (antenna-B). These antennas are implemented by considering FR4 substrate (dielectric constant, εr = 4.4 and loss tangent, tan δ = 0.02). The volumetric dimensions exhibited by the antennas are 38 x 38 x 1.6 mm3. The ground plane dimension ‘LPG’ has been optimized specifically with a recently developed teaching-learning-based optimization algorithm. Depending on the specifications, this amalgamated fractal approach resulted in a suitable structure. Fabrication and testing of antenna-B is done in order to justify the proposed strategy. Measured results depict that the fabricated antenna operates at six fundamental resonances with acceptable gain values. A bandwidth of 1.97%, 7.47%, 5.46%, 4.04%, 4.37% and 4.53% is evaluated at the respective bands. Radiation patterns provided by antenna-B are arbitrary bidirectional/ omnidirectional. In addition, the influence of specific design patterns on the performance of antenna-B is studied. Experimental measurements are presented and compared with the simulated ones. From practical outcomes, it is suggested that the proposed antenna-B can be useful for several wireless communication applications such as Satellite communication for downlink, Fixed satellite communication, Radiolocation, Direct broadcast satellite communication, and Radars.