Dual-Polarized Frame-Integrated Slot Arrays for 5G Mobile Handsets
Hui Li, Yibo Cheng, Liang Mei, Fei Wu
Abstract
In this letter, dual-polarized cavity-backed bow-tie slot arrays are designed and integrated on the frame of the mobile handset. The bandwidth is firstly enhanced for the cavity-backed slot antenna using hybrid modes, with a wide band of 4.1 GHz achieved by dual resonances. However, the hybrid modes result in poor isolation between the orthogonally placed antennas, and a tradeoff between bandwidth and mutual coupling is made, which provides an isolation of above 13 dB between the ports. Two antenna arrays, with each composed of four dual-polarized cavity-backed slot units, are then utilized on the longer metal frames of the handset. The scanning beamwidth for each array is 138° for the gain of above 7 dBi. The 3-D coverage efficiency of the antenna reaches 52% for a threshold gain of 5 dBi. Thus large coverage area and high gain are achieved simultaneously by the dual-polarized frame integrated slot arrays. The proposed antenna arrays are suitable for mobile handsets for their simple structure, high integration, dual polarizations, high gain, and large coverage area.