Analysis and design of dual band compact stacked Microstrip patch antenna with defected ground structure for WLAN/WiMax applications

A compact Microstrip-Line-Fed stacked patch antenna is proposed for WLAN/WiMax applications. A circular shaped defect is embedded in the ground plane and antenna is stacked by a circular patch with air gap. Dual band characteristic is achieved at 2.55 GHz and 5.25 GHz with a compactness of 36%. The antenna is proposed for WiMax and WLAN applications according to IEEE 802.16 and IEEE 802.11a/n standards, respectively. Further, the proposed structure is stacked using a dielectric superstate with air gap. Proposed structure resonates at 2.45 GHz and 5.1 GHz and is suitable for WLAN applications according to IEEE 802.11b/g/n, and IEEE 802.11a/n standards, respectively. The first band of this configuration covers the ISM band. The compactness further improves to the value of 38.3%. A novel theoretical analysis is proposed for the stacked antenna with defected ground plane. The structures are analyzed using Ansoft HFSS v.14 based on Finite Element Method (FEM). Suppression in cross-polarization level of the proposed antenna is achieved. The measured results of fabricated antennas are in good agreement with simulated and theoretical results.