Multi Resonant Stacked Micro Strip Patch Antenna Designs for IMT, WLAN & WiMAX Applications

In this paper, stacked multi resonant slotted micro strip patch antennas (MPA) have been proposed which are suitable to be used for GSM, WLAN standard and WiMAX applications. The antennas have been designed using substrate of FR4 material. In the designed antennas, substrates having different thickness have been used. The performance of designed antenna has been observed by comparing without air gap between the stacks with same antenna having air gap of 0.8 mm between two stacks. It has been observed that air gap in stacking results in increase of antenna impedance bandwidth. The bottom stack of designed antenna has a radiating patch of circular shape and the patch on the upper stack is of rectangular shape. The antenna has a feed line which is connected to circular patch . The designed antennas have a defected ground structure in order to improve the antenna performance. The antenna performance has been measured in terms of antenna parameters such as impedance bandwidth, Return loss, antenna impedance, VSWR and Directivity. The designed antenna results have been simulated in CST Microwave Studio 2010. The practically designed antennas have been tested successfully by using Network analyzer E5071C. It has been observed that the practical results closely match with theoretical results.