An electromagnetic invisibility cloaking device with a broadened cloaking bandwidth and/or a tunable frequency of operation. The cloaking device includes an object (e.g., antenna) and a metasurface (301) that conforms to the surface design of the object. The metasurface includes an array of metal cells (302A, . . . , 302Y), where each of the metal cells includes a circuit element (304) (e.g., active, passive, negative impedance converter element). The array of metal cells may be represented as an array of metal square patches, a mesh grid, horizontal or vertical conductive strips, or any arbitrary combination of unit cell patterns, where each opening, or a subset of them, in such an array includes an embedded circuit element. By incorporating the circuit elements in the conformal metasurface, the cloaking bandwidth is broadened and the frequency of operation is actively controlled and tuned.