A Compact Broadband Printed Circular Slot Antenna with Stair Shaped Ground Plane

This is the first communication reporting a compact broadband printed circular slot antenna with stair shaped ground plane in which bandwidth is enhanced mainly in the lower frequency band on adding 19 strips at regular space intervals in the partial ground plane. The impedance matching at specific band (7.1-8.4 GHz) takes place as a result of circular slot in the patch. The proposed structure is printed on an FR4 substrate with epsilon(r) = 4.3 and 0.025 loss tangent over a compact volume of 20 x 25 x 1.5 mm(3). The impedance bandwidth (S-11 < -10 dB) of the proposed antenna is 133.7% (3.0 15.1 GHz). The antenna exhibits 4.9 dB peak gain and 74% peak radiation efficiency in the operating band. Satisfactory results and such a simple and easy to fabricate design with compact space make the proposed antenna a suitable choice for UWB applications, 5.2/5.8 GHz WLAN bands, 3.5/5.5 GHz WiMAX bands, X band (8-12 GHz) and other wireless communication systems. Measured and simulated results are in good agreement, affirming the simulation process. Omnidirectional radiation patterns are generally observed in the operating band of the designed antenna.