Overcoming limitations of passive invisible antennas through bianisotropic nonreciprocal mantle cloaks

This paper explores the use of bianisotropic mantle cloaks to reduce the scattering of a dipole antenna at its own operation frequency, preserving the radiating properties in transmission mode. The proposed model is based on the use of generalized sheet transition conditions to derive the susceptibilities that make the metasurface operate as a nonreciprocal transparent cloak characterized by zero scattering for external illumination and full transmission for antenna radiation. The ideal metasurface cloak is then implemented through an active metasurface integrating transistors acting as isolators. Simulation results confirm the proper behavior of the cloaked antenna, which exhibits excellent radiation performances in transmission mode and a low-scattering cross section in receiving mode.