Z. Li, Y. Rahmat-Samii and T. Kaiponen, ”Bandwidth Study of a Dual Band PIFA on a Fixed Substrate for Wireless Communication,” IEEE Transactions on Antennas and Propagation, Vol. 1, Provo, 2003, pp. 22-27.
 D. Liu and B. Gaueher, “A Tri-Band Antenna for WLAN Applications,” Proceedings of the IEEE Antenna Propagation Society International Symposium and USNC/ URSI National Radio Science Meeting, Vol. 2, Columbus, June 2003, pp. 18-21.
 M. Manteghi and Y. R. Samii, “Novel compact Tri-Band Two-Element and Four-Element MIMO Antenna Designs,” IEEE Antenna Propagation Society International Symposium, Albuquerque, 9-14 July 2006, pp. 4443-4446. doi:10.1109/APS.2006.1711620
 P. S. Hall, C. T. P. Song, H. H. Lin, H. M. Chen, Y. F. Lin and P. S. Cheng, “Parametric Study on the Characteristics of Planar Inverted-F Antenna,” IEE Proceeding of Microwave Antennas and Propagation, Vol. 152, No. 6, 2005.
 K. L. Virga, and Y. R. Samii, “Low-Profile Enhanced-Bandwidth PIFA Antennas for Wireless Communication Packaging,” IEEE Transaction on Microwave Theory and Techniques, Vol. 45, No. 10, 1997, pp. 1879-1888. doi:10.1109/22.641786
 N. A. Saidatul, A. A. H. Azremi, P. J. Soh, R. B. Ahmad and S. R. Norra, “A Parametric Study of Broadband Planar Inverted F Antenna for WLAN Application,” International Conference on Electronic Design, Penang, 1-3 December 2008, pp. 1-6.
 T. Y. Wu and K. L. Wong, “On the Impedance Band0 width of a Planar Inverted-F Antenna for Mobile Handsets,” Microwave and Optical Technology Letters, Vol. 32, No. 4, 2002, pp. 249-251. doi:10.1002/mop.10145
 A. T. Arkko and E. A. Lehtola, “Simulated Impedance Bandwidths, Gains, Radiation Patterns and SAR Values of a Helical and a PIFA Antenna on Top of Different Ground Planes,” 11th International Conference on Antennas and Propagation, Vol. 2, 17-20 April 2001, pp. 651-654. doi:10.1049/cp:20010370
 A. K. Bhattacharya, “Effects of Ground Plane and Dielectric Truncations on the Efficiency of a Printed Structure,” IEEE Transactions on Antenna and Propagation, Vol. 39, No. 3, 1991, pp. 269-272.
 S. Fujio, “Effects of Ground Size on Plate Inverted-F Antenna,” IEEE International Workshop on Antenna Technology, Small Antennas and Novel Materials, White Plain, 6-8 March 2006, pp. 269-272. doi:10.1109/IWAT.2006.1609027
 M. C. Fabres, E. A. Daviu, A. V. Nogueira and M. F. Bataller, “The Theory of Characteristic Modes Revisited: A Contribution to the Design of Antennas for Modern Applications,” IEEE Antennas and Propagation Magazine, Vol. 49, No. 5, 2007, pp. 52-68.
 H. T. Chattha, Y. Huang and Y. Lu, “PIFA Bandwidth Enhancement by Changing the Widths of Feed and Shorting Plates,” IEEE Antennas and Wireless Propagation Letters, Vol. 8, Salt Lake City, 2009, pp. 637-640. doi:10.1109/LAWP.2009.2023251