In this proposed antenna, mushroom type EBG structures are used for suppressing the surface waves. These structures are periodic metallic patches, which are connected to the ground plane with vias. The most important characteristic of the EBG structure is their stop band frequency. By the help of this stop band, the surface waves of the proposed antenna are suppressed. Thus by the suppression of surface waves, the bandwidth of microstrip antenna is improved at same operating frequency from 9.6% to 15.5% i.e 5.9%.

For overcoming the limitation on Bandwidth of a general Microstrip antenna, work on U-shaped patch antenna with two equal arms on FR4 epoxy substrate is presented. A U-shaped slot is introduced on the square shaped ground plane just under the U-shaped patch. In this communication the effect of size and shape of the ground plane on impedance bandwidth is studied. Maximum impedance bandwidth of 13% (5.1-5.8 GHz) is obtained with introduction of U-shaped slot on the square shaped ground plane. The Voltage Standing Wave Ratio of the antenna at desire frequency is found to be 1.2. The results from simulations are confirmed with Vector Network Analyser. The proposed antenna is simple in structure & smaller in size as compared to the regular stacked or coplanar parasitic patch antennas. The proposed antenna gives high gain & wideband, with simple & compact structure. It is highly suitable for wireless communications.

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