A low SAR WWAN antenna design for tablet application

A novel low SAR WWAN antenna structure is presented in this paper. The proposed 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 built in a 7 inch panel industrial tablet device and it is constructed an IFA (inverted-F antenna) with a shorted loop structure which can support 850/1800/2100 band of WWAN system. It covers 824–894 MHz/1850∼1990 MHz/2110∼2170 MHz and operates with around 40% antenna efficiency across these bands. The measured active performance of TRP is about 19.5–21.5 dBm in both WCDMA Band II and Band V and about 28.5 dBm and 27.5 dBm in GRPS 850/1900 bands, respectively. The proposed antenna has good SAR (Specific Absorption Rate) performance with less than 1.6 W/Kg and can meet FCC SAR limitation. All simulation data are simulated by SPEAG SEMCAD software tool [1] and SAR test results are measured by SPEAG DASY5 SAR equipment.