Mitigation of the finger loading effect in handset antennas

The effect of the human body over the radiation of handset antennas is a critical issue that have to be considered to ensure a good handset antenna performance. Among the human body effect, the finger is of particular interest since it is usually placed over the antenna area which may cause detuning and/or reduction of the efficiency. To mitigate the finger loading effects, a novel handset antenna consisting of two small antennas distributed along the ground plane is proposed. The distributed antenna system is compared with a single antenna having a broadband matching network, so both designs feature enough bandwidth to cover the GSM850 (824–890MHz) and GSM900 (880–960MHz) communication systems. The finger effect is analyzed in terms of efficiency using a phantom hand. Efficiency is measured for different finger locations concluding that the distributed antenna system is more robust to the finger loading effect.

[1]  A. Hirata,et al.  Correlation of maximum temperature increase and peak SAR in the human head due to handset antennas , 2003 .

[2]  Juan Jose Arenas,et al.  Balanced and single‐ended handset antennas: Free space and human loading comparison , 2009 .

[3]  W.J. Krzysztofik.  Meandered Double-PIFA Antenna - Handset / Human Interaction , 2006, 2006 International Conference on Microwaves, Radar & Wireless Communications.

[4]  M. Bank,et al.  The Development of a Cellular Phone Antenna with Small Irradiation of Human-Organism Tissues , 2007, IEEE Antennas and Propagation Magazine.

[5]  Jaume Anguera Pros,et al.  A systematic method to design broadband matching networks , 2010, EuCAP 2010.

[6]  Carles Puente,et al.  Coupled monopole antenna design for multiband handset devices , 2010 .

[7]  J. Anguera,et al.  Enhancing the Performance of Handset Antennas by Means of Groundplane Design , 2006, IEEE International Workshop on Antenna Technology Small Antennas and Novel Metamaterials, 2006..

[8]  M. A. Stuchly,et al.  Modeling of human interaction with antennas using the finite difference time domain technique , 1998, 1998 IEEE-APS Conference on Antennas and Propagation for Wireless Communications (Cat. No.98EX184).

[9]  H. Morishita,et al.  Characteristics of a balance-fed loop antenna system for handsets in the vicinity of human head or hand , 2000, IEEE Antennas and Propagation Society International Symposium. Transmitting Waves of Progress to the Next Millennium. 2000 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (C.

[10]  O. Fujiwara,et al.  ON AVERAGING MASS OF SAR CORRELATING WITH TEMPERATURE ELEVATION DUE TO A DIPOLE ANTENNA , 2008 .

[11]  Carles Puente,et al.  A systematic method to design single-patch broadband microstrip patch antennas , 2001 .

[12]  L.P. Ligthart,et al.  Analysis of Mobile Phone Antenna Impedance Variations With User Proximity , 2007, IEEE Transactions on Antennas and Propagation.

[13]  K. R. Boyle,et al.  User Interaction Studies on Handset Antennas , 2007 .

[14]  B.S. Collins,et al.  A Multi-Band Hybrid Balanced Antenna , 2006, IEEE International Workshop on Antenna Technology Small Antennas and Novel Metamaterials, 2006..

[15]  Sungtek Kahng,et al.  MULTIBAND HANDSET ANTENNA USING SLOTS ON THE GROUND PLANE: CONSIDERATIONS TO FACILITATE THE INTEGRATION OF THE FEEDING TRANSMISSION LINE , 2009 .

[16]  J. Anguera,et al.  Multiband Handset Antenna With a Parallel Excitation of PIFA and Slot Radiators , 2010, IEEE Transactions on Antennas and Propagation.

[17]  A. Schiavoni,et al.  SAR generated by commercial cellular phones-phone modeling, head modeling, and measurements , 2000 .

[18]  K. M. Lee,et al.  Analysis of mutual coupling between a finite phased array of dipoles and its feed network , 1988 .

[19]  M. Ribo,et al.  Multiband Handset Antenna Combining a PIFA, Slots, and Ground Plane Modes , 2009, IEEE Transactions on Antennas and Propagation.

[20]  Carles Puente,et al.  Analysis of the human body on the radiation of FM handset antenna , 2009 .

[21]  Jaume Anguera,et al.  Enhancing robustness of handset antennas to finger loading effects , 2009 .

[22]  P. McEvoy,et al.  Low SAR Ferrite Handset Antenna Design , 2006, IEEE International Workshop on Antenna Technology Small Antennas and Novel Metamaterials, 2006..