Multiple Tri-Beam Low Scanning Loss Metasurface Antenna for Wide-Angle Coverage by Superposing Focusing and Periodic Phases

A multiple tri-beam low scanning loss millimeter-wave (mmW) transmissive metasurface antenna for wide-angle coverage is proposed. The aperture phase distribution of the proposed metasurface is the superposition of the focusing phase and the periodic phase. Theoretical studies show that the size of the periodic phase element determines the directions of the three beams, and the periodic phase difference determines the amplitude ratio between the beams. The metasurface is designed according to the calculated phase and five patch antennas are adopted as the integrated linear feed array. A transmissive metasurface antenna prototype is fabricated for measurement verification. Good agreement is observed between the simulation and measurement. The measured results show that the proposed metasurface antenna realizes the tri-beam scanning range of ±63°, and the scanning loss of 2.9 dBi is within a reasonable range.