Abstract: An electrically small antenna, such as one physically sized appropriate to a mobile device, can be tuned in response to a detected change that can result in poorer reception using the electrically small antenna. Such detected changes include a detected change in the connectivity of a wired accessory relative to the mobile device, a detected change in a position of the mobile device, and a detected change of an audio channel selected by the mobile device. To minimize any user impact of the retuning of the electrically small antenna, a timer can be initiated and the antenna can be retuned during an opportune time, such as when one or more signal metrics associated with a signal being provided to the user drop below a threshold, or when the timer expires, whichever occurs first.

Abstract: An electromagnetic field probe is provided that is capable of measuring four electromagnetic field components in a spatial plane tangential to the central axis of the probe. The probe included two dipoles and two loops. The dipoles are disposed about the central axis at substantially 90 degree angles, while the loops are disposed from 45 to 225 and from 135 to 315 degrees, respectively. In one embodiment, a plurality of flexible conductors, signal combiners and switches are used to couple the dipoles and loops to a network or spectrum analyzer. To isolate the effects of field components that are incident to the central axis of the probe, a 180 degree signal combiner may be employed to separate the common mode signals.