Dual Polarized Patch Antenna Array with Capacitive Proximity Sensor for Hand Grip Detection in 5G mmWave Mobile Devices

We propose a novel dual polarized patch antenna array with a capacitive proximity sensor function for detecting the user's hand on 5G millimeter-wave mobile devices. The proposed antenna array consists of eight proximity-coupled-fed patch elements that generate dual polarized waves. Each element is composed of one radiating patch, two orthogonal proximity-coupled feeds, and a ground plane. The patch also serves as a proximity sensor by using the capacitance change of the patch that occurs when the user's hand approaches the patch. The proposed antenna array is designed to operate in the 5G n257 band (26.5 to 29.5 GHz). The simulation results show a stable gain of 13.6-14.0 dBi in the 5G n257 band and a cross-polarization of below -23 dB at 28 GHz. It is also shown that each array element can act as a capacitive proximity sensor that exhibits a 100 fF capacitance change upon hand proximity.