Wideband Shared-Aperture Antenna for Full-Screen 5G Mobile Devices

This paper presents a novel shared-aperture smartphone antenna for sub-6 GHz and millimeter-wave (mmWave) bands. The proposed antenna module comprises a four-element mmWave patch antenna array integrated into a wideband sub-6 GHz slot antenna. The mmWave antenna covers the frequency band 26.5-29.5 GHz with isolation over 16 dB, and the sub-6 GHz antenna covers several bands on the frequency range 3.4-6.0 GHz with isolation over 15 dB. The key features in the proposed concept are that a metal part of the sub-6 GHz antenna acts as a ground plane for the mmWave antenna array, and both antennas are located solely on the metal rim enabling a full edge-to-edge screen. The antenna achieves a high total efficiency of 65-95% and -3 dB beam steering range ±40°. A prototype is manufactured, and measurements verify wideband operation and high isolation in both frequency bands. The four-element multiple-input multiple-output (MIMO) operation with the proposed shared aperture antenna is demonstrated at the sub-6 GHz band.