Miniaturization of electromagnetic band gap structures for mobile applications

Abstract

[1] It is well known that interference of the human body affects the performance of the antennas in mobile phone handsets. In this contribution, we investigate the use of miniaturized metallodielectric electromagnetic band gap (MEBG) structures embedded in the case of a mobile handset as a means of decoupling the antenna from the user's hand. The closely coupled MEBG concept is employed to achieve miniaturization of the order of 15:1. Full wave dispersion relations for planar closely coupled MEBG arrays are presented and are validated experimentally. The performance of a prototype handset with an embedded conformal MEBG is assessed experimentally and is compared to a similar prototype without the MEBG. Reduction in the detuning of the antenna because of the human hand by virtue of the MEBG is demonstrated. Moreover, the efficiency of the handset when loaded with a human hand model is shown to improve when the MEBG is in place. The improvements are attributed to the decoupling of the antenna from the user's hand, which is achieved by means of suppressing the fields in the locality of the hand.Citation: Goussetis, G., A. P. Feresidis, G. K. Palikaras, M. Kitra, and J. C. Vardaxoglou (2005), Miniaturization of electromagnetic band gap structures for mobile applications, Radio Sci., 40, RS6S04,

Design of compact patch type curved frequency selective surface

“…The center frequency is reduced for the novel structure by 29.60% and 60% compared to swastika and cross dipole design, respectively . For application in mobile handsets, a compact FSS is very useful to implement high impedance surface (HIS) …”

Interwoven convoluted element frequency selective surfaces with wide bandwidths

“…Also, when backed by a closely spaced ground plane, FSS form what are known as High Impedance Surfaces (HIS) [1], which can reduce back scatter and improve gain when used as ground planes for antennas. If the element size is sufficiently reduced, it becomes possible to implement HIS at mobile bands for use in handsets [2].…”