“…In the literature, different shapes of the single-band and multi-band monopole antennas have been developed, such as H-shaped [11], circular-shaped [12], U-shaped open stub [13], M-shaped open stub [14], L-shape with coupled branch strip [9], L-shaped stub folded into U-shaped [4], D-shaped [15], U-shaped with rectangular patch inside [16], square spiral loop [17], tapered rectangular patch antenna [5], and symmetric bow-tie circular patch antenna [18]. Dual-band or multi-band operations can be obtained by etching some slots either in the radiating elements [3,[18][19][20][21][22], in the ground plane of the antennas [23][24][25][26], or both [9,27,28]. A square microstrip patch etched with four symmetrical slots [29][30][31][32][33] has been proposed for nondegenerate dual-mode filter applications.…”