The ornamental design for a multi-band antenna, as shown and described.
The only FIGURE is a front elevational view of a multi-band antenna showing our new design.
The claimed design is so thin that it is barely discernable in top, bottom, and side views. All elements of the claimed design are flat and coplanar. The contiguous shaded area and the larger circle are the only areas that are claimed.
The broken line portion of the FIGURE is included to show unclaimed subject matter only and forms no part of the claimed design.