Beam Steering Toward Multibeam Radiation by Time-Coding Metasurface Antennas

By demand enhancement in the cellular communications, critical needs for the next generation of the phased array antenna are grown. In this article, the time-modulated array is combined with the relatively recent coding metasurface theory to introduce time-coding metasurface antenna (TCMA). This innovative antenna design facilitates flexible spatial modulation of electromagnetic (EM) waves without using complicated feeding network and traditional phase shifter. Hence, it enables the generation of multiple concurrent but independent-directive high-gain beams to cover a predefined angular range, unlike the conventional array antenna which has its single-directive beam that covers only one user at cellular communication. The article focuses on the theoretical analysis of a TCMA designed with embedded 2-bit p-i-n diodes, which is also successfully fabricated. Applying various time sequences, the proposed array showcases the ability to steer beams at the center frequency and concurrently generate multiple beams at different frequencies, each with specific radiation angles. The flexibility and capability of the proposed metasurface antenna is used for different communication applications.