Wwan/lte printed loop tablet computer antenna and its body sar analysis
Corresponding Author
Kin-Lu Wong
Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung 804, TaiwanSearch for more papers by this authorWan-Jhu Wei
Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
Search for more papers by this authorLiang-Che Chou
Department of High Frequency Business, Yageo Corporation Nantze Branch, Kaohsiung 811, Taiwan
Search for more papers by this authorCorresponding Author
Kin-Lu Wong
Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung 804, TaiwanSearch for more papers by this authorWan-Jhu Wei
Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
Search for more papers by this authorLiang-Che Chou
Department of High Frequency Business, Yageo Corporation Nantze Branch, Kaohsiung 811, Taiwan
Search for more papers by this authorAbstract
A WWAN/LTE printed loop antenna for tablet computer application is presented.The printed loop antenna is a half-wavelength loop strip coupled-fed by a patch monopole, which performs not only as a coupling feed but also as an efficient radiator for the antenna. By embedding a printed distributed inductor in the loop strip, dual-resonance excitation of the half-wavelength mode of the coupled-fed loop antenna is obtained, which forms the antenna's lower band at about 800 MHz to cover the LTE700/GSM850/900 operation (704–960 MHz). The antenna's upper band is formed by both the resonant modes contributed by the patch monopole and the higher order resonant modes contributed by the loop strip. The upper band shows a large bandwidth (>1 GHz) to cover the GSM1800/1900/UMTS/LTE2300/2500 operation (1710–2690 MHz). Further, with a planar and compact structure (12 × 75 mm2), the antenna is suitable to be disposed in the limited space inside the tablet computer and meets the body specific absorption rate (SAR) requirement (<1.6 W/kg for 1-g body tissue) for practical applications. Details of the proposed antenna and its body SAR results are presented. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2912–2919, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26377
REFERENCES
- 1 R.L. Li, E.M. Tentzeris, J. Laskar, V.F. Fusco, and R. Cahill, Broadband loop antenna for DCS-1800/UMT-2000 mobile phone handsets, IEEE Microw Wirel Compon Lett 12 ( 2002), 305–307.
- 2 B.K. Yu, B. Jung, H.J. Lee, F.J. Harackiewwicz, and B. Lee, A folded and bent internal loop antenna for GSM/DCS/PCS operation of mobile handset applications, Microw Opt Technol Lett 48 ( 2006), 463–467.
- 3 B. Jung, H. Rhyu, Y.J. Lee, F.J. Harackiewwicz, M.J. Park, and B. Lee, Internal folded loop antenna with tuning notches for GSM/GPS/DCS/PCS mobile handset applications, Microw Opt Technol Lett 48 ( 2006), 1501–1504.
- 4 C.I. Lin and K.L. Wong, Internal meandered loop antenna for GSM/DCS/PCS multiband operation in a mobile phone with the user's hand, Microw Opt Technol Lett 49 ( 2007), 759–765.
- 5 Y.W. Chi and K.L. Wong, Internal compact dual-band printed loop antenna for mobile phone application, IEEE Trans Antennas Propag 55 ( 2007), 1457–1462.
- 6 C.I. Lin and K.L. Wong, Internal multiband loop antenna for GSM/DCS/PCS/UMTS operation in the small-size mobile phone, Microw Opt Technol Lett 50 ( 2008), 1279–1285.
- 7 K.L. Wong and C.H. Huang, Printed loop antenna with a perpendicular feed for penta-band mobile phone application, IEEE Trans Antennas Propag 56 ( 2008), 2138–2141.
- 8 Y.W. Chi and K.L. Wong, Half-wavelength loop strip fed by a printed monopole for penta-band mobile phone antenna, Microw Opt Technol Lett 50 ( 2008), 2549–2554.
- 9 Y.W. Chi and K.L. Wong, Compact multiband folded loop chip antenna for small-size mobile phone, IEEE Trans Antennas Propag 56 ( 2008), 3797–3803.
- 10 W.Y. Li and K.L. Wong, Seven-band surface-mount loop antenna with a capacitively coupled feed for mobile phone application, Microw Opt Technol Lett 51 ( 2009), 81–88.
- 11 Y.W. Chi and K.L. Wong, Very-small-size printed loop antenna for GSM/DCS/PCS/UMTS operation in the mobile phone, Microw Opt Technol Lett 51 ( 2009), 184–192.
- 12 Y.W. Chi and K.L. Wong, Very-small-size folded loop antenna with a band-stop matching circuit for WWAN operation in the mobile phone, Microw Opt Technol Lett 51 ( 2009), 808–814.
- 13 Y.W. Chi and K.L. Wong, Quarter-wavelength printed loop antenna with an internal printed matching circuit for GSM/DCS/PCS/UMTS operation in the mobile phone, IEEE Trans Antennas Propag 57 ( 2009), 2541–2547.
- 14 W.Y. Li and K.L. Wong, Small-size WWAN loop chip antenna for clamshell mobile phone with hearing-aid compatibility, Microw Opt Technol Lett 51 ( 2009), 2327–2335.
- 15 H. Kanj and S.M. Ali, Compact multiband folded 3-D monopole antenna, IEEE Antennas Wirel Propag Lett 8 ( 2009), 185–188.
- 16 A.R. Razali and M.E. Bialkowski, Coplanar inverted-F antenna with open-end ground slots for multiband operation, IEEE Antennas Propag Lett 8 ( 2009), 1029–1032.
- 17 C.L. Liu, Y.F. Lin, C.M. Liang, S.C. Pan, and H.M. Chen, Miniature internal penta-band monopole antenna for mobile phones, IEEE Trans Antennas Propag 58 ( 2010), 1008–1011.
- 18 K.L. Wong and S.C. Chen, Printed single-strip monopole using a chip inductor for penta-band WWAN operation in the mobile phone, IEEE Trans Antennas Propag 58 ( 2010), 1011–1014.
- 19 T.W. Kang and K.L. Wong, Chip-inductor-embedded small-size printed strip monopole for WWAN operation in the mobile phone, Microw Opt Technol Lett 51 ( 2009), 966–971.
- 20American National Standards Institute (ANSI), Safety levels with respect to human exposure to radio frequency electromagnetic fields, 3 kHz to 300 GHz, ANSI/IEEE standard C95.1, American National Standards Institute, Boulder, CO, 1999.
- 21IEC 62209-1, Human exposure to radio frequency fields from hand-held and body-mounted wireless communication devices—Human models, instrumentation, and procedures, Part 1: Procedure to determine the specific absorption rate (SAR) for hand-held devices used in close proximity to the ear (frequency range of 300 MHz to 3 GHz), IEC, 2005.
- 22 C.H. Li, E. Ofli, N. Chavannes, and N. Kuster, Effects of hand phantom on mobile phone antenna performance, IEEE Trans Antennas Propag 57 ( 2009), 2763–2770.
- 23 C.H. Chang and K.L. Wong, Small-size printed monopole with a printed distributed inductor for penta-band WWAN mobile phone application, Microw Opt Technol Lett 51 ( 2009), 2903–2908.
- 24Federal Communications Commission, Office of Engineering and Technology, Mobile and Portable Device RF Exposure Equipment Authorization Procedures, OET/Lab Knowledge Database publication number 447498 item 7, Federal Communications Commission, 2007.
- 25 K.L. Wong and L.C. Lee, Multiband printed monopole slot antenna for WWAN operation in the laptop computer, IEEE Trans Antennas Propag 57 ( 2009), 324–330.
- 26 C.H. Chang and K.L. Wong, Internal coupled-fed shorted monopole antenna for GSM850/900/1800/1900/UMTS operation in the laptop computer, IEEE Trans Antennas Propag 56 ( 2008), 3600–3604.
- 27 X. Wang, W. Chen, and Z. Feng, Multiband antenna with parasitic branches for laptop applications, Electron Lett 43 ( 2007), 1012–1013.
- 28 C. Zhang, S. Yang, S. El-Ghazaly, A.E. Fathy, and V.K. Nair, A low-profile branched monopole laptop reconfigurable multiband antenna for wireless applications, IEEE Antennas Wirel Propag Lett 8 ( 2009), 216–219.
- 29Tissue Simulating Liquid for SAR Measurement, NTT Advanced Technology Corporation. Available at: http://www.ntt-at.com/ products_e/sar/index.html.
- 30Available at: http://www.ansoft.com/products/hf/hfss/, ANSYS HFSS.
- 31 K.L. Wong and S.J. Liao, Uniplanar coupled-fed printed PIFA for WWAN operation in the laptop computer, Microw Opt Technol Lett 51 ( 2009), 549–554.
- 32 K.L. Wong and F.H. Chu, Internal planar WWAN laptop computer antenna using monopole slot elements, Microw Opt Technol Lett 51 ( 2009), 1274–1279.
- 33 T.W. Kang and K.L. Wong, Internal printed loop/monopole combo antenna for LTE/GSM/UMTS operation in the laptop computer, Microw Opt Technol Lett 52 ( 2010), 1673–1678.
- 34 K.L. Wong, W.J. Chen, L.C. Chou, and M.R. Hsu, Bandwidth enhancement of the small-size internal laptop computer antenna using a parasitic open slot for the penta-band WWAN operation, IEEE Trans Antennas Propag 58 ( 2010), 3431–3435.
- 35SEMCAD, Schmid & Partner Engineering AG (SPEAG), Germany. Available at: http://www.semcad.com.
