The electromagnetic (EM) beam manipulations such as spatial scanning have always been the focus in information science and technology. Generally, the transmitting and receiving (T/R) beams of the same aperture should be coincident due to the reciprocal theory, and hence, more flexible controls of the spatial information are limited accordingly. Here, we propose a new approach to achieve independent controls of beam scanning in spatial T/R channels based on one aperture made by a nonreciprocal programmable metasurface. The meta-atom is designed to have independent propagation chains for T/R waves by introducing dual-direction power amplifiers (PAs) as the isolators for one-way transparency. A programmable phase shifter with a 360° coverage is loaded with the PA device in the transmitting or receiving chain to realize independent beam scanning in the T/R channels. A prototype of the proposed metasurface is fabricated, and independent beam scanning in the T/R channels is directly acquired with good performance in our measurements. In addition, a proof of concept of integrated sensing and auxiliary communications is accomplished to verify the validity of the presented method.
Keywords: beam scanning; independent manipulations of transmitting and receiving; integrated programmable metasurfaces; nonreciprocal design; programmable metasurface.