A low SAR WWAN antenna design

A low SAR WWAN antenna is presented in this paper. The proposed antenna structure constructed an IFA (inverter-F antenna) with a shorted loop structure for tablet device application with low SAR performance. The antenna elements are printed on a compact size and single layer FR4 substrate of size 51.2 × 8.2 × 0.4 mm³ and fed by a 50 Ω coaxial cable with I-PEX connector. The proposed antenna can support triplet-bands (850/1900/2100) of WWAN communication system that covers 824~894 MHz, 1850~1990 MHz and 1920~2170 MHz and operate with around 40% radiation efficiency across these bands. The active performance of TRP we measured is about 28.5 dBm and 27.5 dBm in GRPS 850/1900 bands respectively and about 19.5~21.5 dBm in both WCDMA band II and band V. The SAR (specific absorption rate) performance of tablet back and tip side that we measured are less than 1.3 mW/g in low and high band which can meet FCC SAR limitation within 1.6 mW/g. All simulation data are simulated by SPEAG SEMCAD software tool [1] and SAR results are measured by SPEAG DASY5 SAR equipment.