Millimeter-Wave and Sub-6-GHz Aperture-Shared Antenna and Array for Mobile Terminals Accessing 5G/6G-Enabled IoT Scenarios
Xiaoyue Xia, Fan Wu, Chao Yu, Zhihao Jiang, Jun Xu, Si‐Yuan Tang, Zuojun Wang, Yu Yao, Wei Hong
Abstract
In the era of 5G and beyond, the strategic utilization of both sub-6 GHz and millimeter-wave (mmWave) spectrums supports diverse communication services. Through smartphones, consumers can conveniently access a wide range of 5G/6G-enabled Internet of Things (IoT) scenarios anytime and anywhere. In this paper, mmWave and sub-6 GHz aperture-shared antenna and array are proposed for mobile terminals. For the mmWave antenna design, a slot radiating array is integrated into the metallic frame of a smartphone. This design incorporates a differential square-ring feeder and utilizes hybrid mode operation, enabling dual-polarized radiation capability across a wide operating frequency band. Importantly, this configuration requires only two metal layers with a 1.0-mm profile. Sharing the same frame, an inverted-F antenna (IFA) and a hybrid mode antenna with loop antenna and IFA operation are designed to work in sub-6 GHz bands. With the design principle of equal clearance, the sub-6 GHz antennas can perform well with the coexistence of the mmWave array. This approach is particularly applicable for sub-6 GHz antennas of different modes and frequencies. The proposed 1×4 mmWave phased array prototype demonstrates a -10 dB bandwidth of 23.3-30.8 GHz (covering the 5G n257/258 bands), a beam scanning range of ±40∘, and an in-band realized gain above 10.3 dBi. The sub-6 GHz antennas effectively cover 5G bands n1/2/3/7/18/28. By utilizing impedance tuning technique, the lower band can be further tuned to cover the bands n8/5.