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