Symmetric circular-shaped multiband hybrid fractal antenna using TLBO approach: design and measurement

ABSTRACT

This paper describes the multiband behaviour of several circular-shaped hybrid fractal antennas. Initially, a circular-shaped fractal antenna (antenna-A) is designed and its performance is scrutinised. Afterwards, hybrid fractal approach is utilised in the design process to enhance the operational performance and the resultant structure is named as circular-shaped hybrid fractal antenna (antenna-B). The volumetric dimensions exhibited by the antennas are 38 × 38 × 1.6 mm³. The ground plane dimension ‘L_PG’ has been optimised specifically with a recently developed teaching-learning-based optimisation algorithm. 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.

KEYWORDS:

• Hybrid fractal antenna
• multiband behaviour
• symmetrical circular fractal patterns
• teaching-learning-based optimisation
• radiation pattern
• wireless applications

Disclosure statement

No potential conflict of interest was reported by the author(s).