Design of Broadband Switchable Metasurface With Radiation and Scattering Functions

This letter proposes a broadband switchable integrated metasurface with in-band scattering and radiation capabilities based on the Pancharatnam–Berry (PB) phase. The proposed integrated metasurface is composed of units with different rotations, and its radiation and scattering properties are endowed by loading a bias network. In order to effectively and independently control the radiation and scattering properties of the metasurface, it is possible to achieve this by controlling the states of the p-i-n diodes in the bias network. When the p-i-n diodes are in the <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small> state, the designed metasurface has scattering properties. For normal incidence, it achieves a radar cross-section (RCS) reduction of 10 dB in the frequency range of 5.5 GHz to 9.6 GHz. On the contrary, in the <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> state, the metasurface is converted into a circularly polarized antenna with radiation function, which has an axial ratio of 3 dB in the frequency bandwidth of 6.05 GHz to 9.77 GHz. To verify the radiation and scattering characteristics of the designed metasurface, a 4 × 4 units metasurface structure is fabricated. The measurement results are in good agreement with the simulation results, and the RCS reduction band completely covers the working band of the antenna.