A Miniaturized High Gain MultiBand Microstrip Patch Antenna

This article presents a compact size rectangular patch antenna with dimensions of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.12 \lambda_{0} \times 0.12 \lambda_{0}$</tex> placed on a FR4-epoxy substrate with relative permittivity 4.4 and thickness of 1.6mm. Rectangular slots are introduced on the patch to increase the electrical length of the radiating structure along with defective ground comprising of symmetric rectangular and circular slots on either side of the antenna. An offset feeding technique is proposed to match impedance at low frequency. This results in a miniature sized simple microstrip antenna to resonate at multiple bands 2.4 GHz, 4.42 GHz, 5.93 GHz with - 10dB impedance bandwidth of 14.1%, 4%, 3.3% at 2.4 GHz, 4.42 GHz, 5.93 GHz respectively. The proposed design has the gain values of 3.1dB, 4.3 dB, 4.7 dB gain at 2.4 GHz, 4.42 GHz, 5.93 GHz respectively, making the antenna suitable for Wi-Fi and ISM applications.