A novel configuration of a miniature printed antenna array based on defected ground structure

Abstract

In this paper, a highly miniaturized microstrip antenna array is proposed for the small wireless device. The antenna array is designed to cover the Industrial Scientific Medical band (ISM) at 2.45GHz. The antenna array is miniaturized using a new geometry of defected ground structure (DGS) etched in the ground plane of each radiating element of the antenna array. The array size is 140.74mm by 57.15mm, which means 78.63% miniaturization ratio is achieved at 2.45GHz as compared with a conventional microstrip antenna array with an ordinary ground plane of 367.26 x 102.46mm 2 resonating at the same frequency (2.45GHz). The structure is implemented on an FR-4 substrate of a relative permittivity equal to 4.4, 1.6mm of thickness and 0.025 of loss tangent. This compact antenna array is designed and optimized by using the electromagnetic solver based on finite integration technique, and the results agree with those obtained by the high-frequency electromagnetic field simulation solution (HFSS). The simulated 10-dB return-loss bandwidth of the printed array is about 157.5MHz, whereas the value of gain is about 7.026dB, which is relatively satisfied. Finally, the final circuit of miniaturized antenna array is fabricated and measured.