Summary
International Symposium on Antennas and Propagation
2010
Session Number:4FB4
Session:
Number:4FB4-2
Multifunction Automobile Antennas ─ Conformal, Thin, with Diversity, and Smart
Johnson J. H. Wang, David J. Triplett,
pp.-
Publication Date:2010/11/23
Online ISSN:2188-5079
Summary:
The antenna is a centrepiece of any wireless system, and has been facing technological barriers more fundamental than other components or subsystems of wireless systems. As a result, an enormous amount of effort has been devoted to research in antennas. As predicted in the book by Fujimoto and James [1] and by the senior author in several papers and presentations in the 1990s, the antennas in mobile communications, driven by market needs and technological advances as well as the cost reduction resulting from the global economy, have been moving toward broadband, directional, diversity, smart, conformable, thin, and low cost. These trends have materialized for wireless systems in small portable platforms, such as cell phones. Similarly, the design of automobile antennas has been following this same trend as that of the portable platforms [1?7]. This paper presents the latest design concepts, resulting from advances in the past few years. Table 1 summarizes wireless systems on the automobile. This table is by no means complete, as more and more wireless systems are appearing, such as various mobile satellite communications systems, UWB (ultra-wideband) systems, etc. Nor is the table consistent with all the conventions, some of which change with time or vary with geographical locations. An omnidirectional pattern is generally required for terrestrial services, and a unidirectional pattern of broad beamwidth (with near hemispherical coverage) is required for satellite services. For terrestrial services, the polarization is not crucial (due to multipath propagation); however, generally VP (vertical polarization) is specified, CP (circular polarization) is preferred, and HP or slanted LP (linear polarization) is also acceptable.