A Handgrip-Responsive mmWave Phased Array Antenna-PA Module With Antenna-Based Capacitive Sensor for EIRP Recovery via Adaptive Current Redistribution

This paper presents a 5G/6G millimeter-wave (mmWave) phased array antenna-power amplifier module that recovers the effective isotropic radiated power (EIRP) during a user's handgrip in mobile devices. A sentenna device, which combines a capacitive sensor and an antenna to enable both wireless communication and handgrip detection, is designed and utilized to distinguish between antenna elements blocked by a user's hand and those unblocked within the phased-array system, without using external sensors such as radar sensors. Based on handgrip information from the sentenna devices, current to the front-end circuits of blocked antenna units is cut off and redistributed to those of unblocked units. In the absence of handgrip detection and current redistribution (CR) functions, the measured EIRP of the 1× 4 phased array sentenna system drops from + 31.4 dBm to + 22.4 dBm when up to three sentenna units are blocked. In contrast, with these functions enabled, the worst-case EIRP degradation is limited to + 27.4 dBm, effectively mitigating up to 5 dB of performance loss. Notably, this EIRP recovery is achieved while also improving the output-referred third-order intercept point (OIP3).