“…Slot antennas can be built as a single-layer metallic structure and fed by a CPW [1,3,4,6,7,[15][16][17][18][19][20][21][22][23][24][25][26], or as a two-layer and fed by a microstrip line [2,3,[5][6][7][8][9][11][12][13]27], or even a multilayer structure [14]. They can exhibit wideband [2][3][4][5][6][7][8]11,13,[17][18][19][21][22][23][25][26][27] or multiband behavior [12,[14][15][16]…”