The ornamental design for a multi-element antenna, as shown and described.
FIG. 1 is a top perspective view of a multi-element antenna, and the numerals 1-6 form no part of the claimed design but serve as reference points for FIGS. 3-8.
FIG. 2 is a bottom plan view of the multi-element antenna of FIG. 1.
FIG. 3 is a side view from a 6-1 corner of the multi-element antenna of FIG. 1.
FIG. 4 is a side view from a 2-1 corner of the multi-element antenna of FIG. 1.
FIG. 5 is a side view from a 1 side of the multi-element antenna of FIG. 1.
FIG. 6 is a side view from a 2-3 side of the multi-element antenna of FIG. 1.
FIG. 7 is a side view from a 4 side of the multi-element antenna of FIG. 1.
FIG. 8 is a side view from a 5-6 corner of the multi-element antenna of FIG. 1.
FIG. 9 is a bottom plan view of the multi-element antenna of FIG. 1.
FIG. 10 is a side elevation view from side 1 of the multi-element antenna of FIG. 1.
FIG. 11 is a side elevation view from side 4 of the multi-element antenna of FIG. 1
FIG. 12 is a side elevation view from a 3-2 side of the multi-element antenna of FIG. 1; and,
FIG. 13 is a side elevation view from a 6-5 side of the multi-element antenna of FIG. 1.
The broken lines in the figures depict round holes and numbers that are not part of the claimed design.