Wideband Fractal Circular-Shaped Microstrip Patch Antenna for Recent Wireless Applications

摘要

this paper introduces a design of microstrip patch antenna using two techniques such as fractal geometry and partial ground plane to increase the antenna bandwidth with a reduction in its size. FR4 substrate is used with dimensions (22×22) mm^{2, 1.5 thickness, 4.3 permittivity ?r and 0.02 loss tangent. The type of feeding used to excite this antenna is microstrip line feed. An iterative method of fractal geometry up to the 2nd iteration is used in this design and taking the advantage of a self-similarity property of fractal geometry. The proposed model is investigated for different radius of circular-shaped patch Pr and ground plane length Lg and simulated using High-Frequency Structure Simulator (HFSS) Ver.14 software. The results of the simulation show that when Pr=7.5mm and Lg=4mm, it can achieve the optimum bandwidth with more reduction in reflection coefficient S11 values and good gain. The proposed model has the best impedance matching attained at the 2nd iteration, which equals to 66.3% at center frequency of 7 GHz. The obtained bandwidth of the proposed antenna is 4.7GHz over a frequency range (4.6-9.3) GHz with a peak gain of 4.24dB. Also, the current distribution of the proposed antenna over various frequencies is studied. The proposed model is fabricated and tested by Vector Network Analyzer (VNA). The measured results showed acceptable compatibly with simulated results. This antenna is suitable for recent wireless communication applications including C-band that used for satellite communication, weather radar system, Wi-Fi and ISM band applications.}