LOADED ANNULAR RING SLOT MICROSTRIP ANTENNA FOR WIDEBAND AND MULTI-BAND OPERATION

Wideband and multi-band antennas have become part-and-parcel of modern telecommunication systems. In this article, an annular ring slot microstrip antenna loaded with two pie-shaped circular sectors is presented. With the use of pie-shaped circular sectors along the microstrip feed line, a multi-wider-band operation than for a conventional annular ring slot can be realized. By selecting proper dimensions of the circular sectors, the antenna typically provides three main operating bands and is capable of multi-frequency operations in various personal and wireless applications. From experimental results, with a VSWR <= 2, the antenna achieves three wide bandwidths of 190 MHz (0.88 to 1.07 GHz), 1.83 GHz (1.79 to 3.62 GHz) and 880 MHz (5.05 to 5.93 GHz), which are equivalent to impedance bandwidth of 19.5, 67.7 and 16.03 percent, respectively.