Abstract: An electronic device, like a mobile telephone, has a first section and a second section. The first section and second section are coupled together by a mechanical connection, for example a hinge, swivel or sliding connector. Electronic components in the first section are coupled to electronic components in the second section by conductors capable of transferring power between the first and second sections. A current detector is capable of detecting currents, like surface currents, while a controller is responsive to the current detector. A plurality of reactive elements, like capacitors for example, are coupled to a plurality of switches such that the controller may selectively couple any of the plurality of reactive elements to the conductors by actuating a corresponding switch.

Abstract: An energy density diversity antenna (EDA) has a least a pair of antenna elements, whose feeding points are connected to outputs of a hybrid coupler configured such that a sum and a difference signal may exist at the feed points of the antenna elements. First reactive elements are respectively inserted in the antenna elements proximal the respective feed points. The antenna elements are joined at a point distal from the feed points by a second reactive element, and a third reactive element is coupled between feed lines coupled to the feed points at a location between the feed points and the outputs of the hybrid coupler.