Optically Transparent Single-Layer Dual-Frequency Dual-Polarization Metasurface Applied in Close Proximity to Smartphone Millimeter-Wave Phased Array Antenna Systems

An optically transparent single-layer dual-frequency dual-polarization metasurface operating at 28 GHz and 38 GHz is proposed to enhance millimeter-wave transmission through glass. The unit cell design of the proposed metasurface has three distinct pattern types: square annular, Jerusalem cross, and circular. The former pattern can independently control the low-frequency resonance, while the latter two can control the high-frequency resonance. The proposed metasurface can achieve a large incident angle of 60 degrees for electromagnetic waves in TE and TM polarizations. After the metal layer of the proposed metasurface is meshed, the transparency of the metasurface is significantly improved. The meshed metasurface can be coated on the glass back cover of a smartphone to improve the performance of the millimeter-wave phased array antenna system under the glass back cover without affecting the aesthetics of the smartphone back cover. The prototype of a dual-band patch phased array antenna with the metasurface-coated glass superstrate is fabricated and tested as proof of concept. The experimental results are good and the effectiveness of the proposed metasurface is well verified.