Design and Development of Shamrock leaf shaped fractal Antenna for WLAN/WiMAX applications

Abstract

An innovative fractal shamrock leaf-shaped antenna with built-in filtering performance has been constructed utilising a stepped impedance resonator (SIR). For multi-band, uniformly polarised FR4 substrate functioning, an aperture-coupled slot patch antenna is in use. Portable electronics and fixed-location networks alike have made use of patch antennas. Patch antennas have traditionally suffered from limited gain, power handling, and impedance bandwidth. The proposed layout's primary goal is to employ filtering to dampen harmonics. Inherent advantages of the suggested design produce antennas that are both smaller in size and capable of operating over a wider frequency range. The multilayered fractal shamrock leaf shaped antenna is employed with a resonating frequency of 2.4GHz, 5.8 GHz, 3.5 GHz, 7.9GHz-ITU-R band with FR4 substrate. The SIR dual-band band pass filter is used to suppress the harmonics and reduce the dimension of the whole structure. The proposed antennas were fed by micro strip line and considered apertures coupling feeding techniques for suppressing harmonic frequencies and matching impedances. The number of iteration is varied, which in turn enhances the multiband characteristics. Both the measured and simulated results reveal improved radiation performances and bandwidth. The simulated outcome shows the better outcome in terms of gain and S11(dB)[reflection coeffeceint) i.e., for 2.4GHz (gain value of 3.3 dBi is attained with a S11(dB)[reflection coeffeceint) of -38 dB, for 3.5 GHz (the gain is 38 dBi having S11(dB)[reflection coeffeceint) of -26 dB), for 5.8 GHz (gain is 4.1 dBi with return values -32 dB), for 7.9GHz (the gain is 3.9 dBi having S11(dB)[reflection coeffeceint) of about -20.5 dB).. Thus, from the analysis, it is evident that the proposed design effectively suppresses the harmonics, thereby offering high impedance and better S11(dB)[reflection coeffeceint).