24-1: Invited Paper: Optically Invisible Antenna-on-Display (AoD) Technologies: Review, Demonstration and Opportunities for Microwave, Millimeter-Wave and Sub-THz Wireless Applications

Abstract

This paper provides a detailed overview of an optically invisible phased-array antenna-on-display (AoD) technology for microwave, millimeter-wave (mmWave), and sub-THz wireless scenarios such as wireless communication, radar, sensing etc. The fundamental AoD configuration and stack-up are introduced with numerical results, which proves the trade-off relationship between optical transmittance and RF conductivity. A transverse magnetic patch antenna for Wi-Fi and Bluetooth accessibility is implemented on the active display panel of a real-life smartwatch device. The fully functional smartwatch prototype including the electromagnetic wrist phantom features a total radiation efficiency of 22% at 2.4 GHz. The optically invisible phased-array AoD is fully integrated within the view area of high-resolution OLED display panels of mmWave 5G NR cellular handsets. The fabricated cellular handset prototype including optically invisible beamforming AoD features optical transmittance of more than 88 % and beam scanning of ± 30° with the estimated maximum EIRP of 14.4 dBm. The over-the-air test confirms that the fabricated phased-array AoD prototype satisfies the 3GPP's EVM performance requirement for 5G NR cellular devices. Future work collectively aims to serve as a catalyst for the emergence of future sub-THz 6G mobile devices.