Tightly Embedded Modular Antenna-in-Display (MAiD) Into the Panel Edge of Display With Dual-Polarization for 5G Smartphones

This study introduces a novel modular antenna-in-display (MAiD) concept for advanced smartphone antenna modularization. It focuses on dual-polarization integration in a compact space within the display panel, essential for millimeter-wave (mmWave) 5G smartphones operating in the n257 and n258 bands of FR2. The adaptable MAiD is compatible with various displays, including foldable and slidable types. The MAiD ingeniously utilizes the display panel’s dead space (DS), a narrow 300-<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>m area, for antenna placement. This innovation is integrated into the same layer as the touch sensor (TS). We propose two <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1\times 4$ </tex-math></inline-formula> antenna array configurations within the DS for dual-linear polarization, enhancing capacity through selection diversity. The antennas, named antenna-in-display parallel to DS (AiD-pDS) and antenna-in-display normal to DS (AiD-nDS), are fabricated with a 50-<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>m-thick polyimide film. Their design allows embedding in a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.03\lambda _{0}$ </tex-math></inline-formula> width of the DS. The MAiD achieves impressive 10-dB return-loss bandwidths of 26.7–28.6 GHz and 24.5–28.1 GHz, with measured boresight gains of 9.041 and 8.824 dBi for AiD-pDS and AiD-nDS, respectively. It maintains over 12-dB cross-polarization level (XPL), demonstrating its effectiveness for modern smartphone technologies.