Antenna configured for low frequency applications

Abstract

An antenna configured for low frequency applications on a mobile device includes an antenna element coupled to a conductive structure which, in turn, is coupled to the user of the mobile device such that the user of the mobile device effectively becomes part of the antenna. The conductive structure can include, for example, the device housing being made from a conductive material, a conductive structure embedded inside the device housing, or conductive pads exposed in the device housing. The antenna element is electrically connected to the conductive structure and the user can be coupled to the conductive structure either through direct contact or through capacitive coupling. In addition, the antenna can include an active element configured to boost free space operation efficiency. The active element can include, for example, a low noise amplifier integrated onto a low noise amplifier board. The active element can be at least partially surrounded by a hollow support structure around which an antenna coil is wrapped, where the antenna coil is coupled to the active element. Furthermore, one or more antenna coils can be utilized either separately or in conjunction with the antenna for low frequency applications, where the one or more antenna coils can have integrated therein inductive components and/or active/switching elements that allow the one or more antenna coils to be tuned to a desired frequency.