Design considerations to calculate SAR in multiband MIMO antenna for mobile handsets

MIMO is now widely deployed in mobile devices, but existing exposure guidelines still focus on methodology for single antenna evaluation. MIMO enabled devices are required to comply with standards or internationally recognized guidelines for limiting human exposure to RF fields. Printed MIMO antennas capable of multiband operation which covers GSM 1800/1900, UMTS, WLAN, and several LTE frequency bands designed using CST studio. The flat phantom is used for testing the radiation absorption when the user places the mobile device close to the body, which is referred to as the “Body-worn mode”. The head and hand phantoms are used in the case where a user performs a voice call with the phone, which is referred to as the “Talking Mode”. SAR values calculated in these two modes, Stand-Alone SAR and MIMO SAR methods. Obtain SAR results are below the limit (1.6W/Kg).