Design, modeling and analysis of dual-feed defected ground microstrip patch antenna with wide axial ratio bandwidth

摘要

In this paper, a low profile microstrip patch antenna with defected ground structure is proposed for wide impedance and axial ratio bandwidth. The antenna structure consists of two feed lines with a circular defect loaded in the ground surface. The proposed antenna shows an impedance bandwidth of 71.92% ranging from 8.95 to 19 GHz covering X, Ku and K band applications. The mutual coupling between the two feed lines is suppressed by means of a single and double arc-shaped defect embedded in the ground plane. The mutual coupling is suppressed to a level of - 37.5 dB with improved radiation performance. The measured 3-dB axial ratio bandwidth of the proposed antenna ranges from 8.85 to 11 GHz. An equivalent circuit model of the designed antenna is also proposed for theoretical analysis and theoretical results are verified with simulated and measured results.