A capacitive method for measuring hand grip position on a mobile phone equipped with a dual-band planar inverted-F antenna (PIFA) and a monopole antenna was studied using different electrode arrangements. A capacitive sensor with a dual-electrode configuration and an antenna-integrated capacitive sensor for hand grip recognition were developed. The sensitivities of the sensors were measured along the front, side and back of the phone. The dual-electrode sensor configuration exhibited its best sensitivity of 29 fF at the bottom end of the phone. The PIFA antenna-integrated sensor proved to have sensitivity of 420 fF and the monopole antenna-integrated sensor had sensitivity of 115 fF, making them both reasonable solutions for hand grip sensors in mobile applications.
Vamsi Krishna Palukuru,
Erkki T. Salonen,
"Capacitive Recognition of the User`S Hand Grip Position in Mobile Handsets," Progress In Electromagnetics Research B,
Vol. 22, 203-220, 2010. doi:10.2528/PIERB10042007
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