Antenna

FIG. 1 is a perspective view of an antenna showing my new design; FIG. 2 is a perspective view viewed from another angle thereof; FIG. 3 is a front elevation view thereof; FIG. 4 is a rear perspective view thereof; FIG. 5 is a left side elevation view thereof; FIG. 6 is a right side elevation view thereof; FIG. 7 is a top plan view thereof; FIG. 8 is a bottom plan view thereof; and, FIG. 9 is an enlarged view of the area “ 9 ” shown in FIG. 1 . The broken lines depict portions of the antenna in which the design is embodied that form no part of the claimed design. The dot-dash broken lines indicate where the enlargements have been taken, and form no part of the claimed design.