Co-Designed Millimeter-Wave and Sub-6 GHz Antenna for 5G Smartphones
Qiuyan Liang, Hanieh Aliakbari, Buon Kiong Lau
Abstract
This letter proposes a co-designed millimeter-wave (mm-wave) and sub-6 GHz antenna system. The antenna system consists of four 28 GHz mm-wave arrays with reconfigurable radiation patterns and two sub-6 GHz antennas fed with two corner capacitive coupling elements (CCEs). Each corner CCE is formed by the connected ground planes of two mm-wave arrays in the shared-aperture configuration. The two CCEs are separately matched to cover two sub-6 GHz bands. Each mm-wave array consists of an active patch element and two parasitic patch elements loaded with PIN diodes, realizing 90° beam scanning range with two states of the PIN diodes. The measured results of the fabricated prototype show good agreement with the simulated ones. The prototyped mm-wave arrays cover the band 27.5–28.35 GHz, and each achieves 90° beam scanning at 28 GHz, with measured peak realized gain of 7.9 dBi. The CCE ports cover the two sub-6 GHz bands of 0.79–0.96 GHz and 1.7–5 GHz, with measured isolation of above 17 dB and 20 dB, respectively. The mm-wave band isolation is above 26 dB.