Miniature dielectrically loaded GPS antennas for robust US E-911 position location

Abstract

Hard lessons have been learned about the performance that is required from the antenna as GPS positioning systems come into use in wireless communication products. As handsets reach more compact size there has as a result been a reduction in volume available to house antennas. Whilst size/performance tradeoffs in the terrestrial system have accommodated the consequent reductions in radiation efficiency, there is no available way to mitigate this loss for the GPS system as it uses signals that are transmitted from satellites. This reduction in radiation efficiency may not be so critical in some applications, but when applied to finding ones location in emergency circumstances, the loss in the GPS antennas performance should not be taken frivolously. What is required is antenna technology, which maintains a high enough performance despite occupying a small volume, being in close proximity to energy absorbing human tissues of the user and in the presence of noise and distortion from the radios that share the handset platform.