Abstract: Systems and methods for optimizing performance of personal area network (PAN) systems that use electric fields as communication media between PAN transmitters carried by people and PAN receivers mounted on computers to which selective access is sought to be established. Multiple PAN receiver antennae are mounted on a keyboard, such that if a person with a PAN transmitter rests her arms on or near the keyboard, sufficient signal from the transmitter is sensed by one or more of the receiver antennae even though some of the signal is shunted away from the receivers through the arms. Also, a driven shield insulates a PAN receiver from nearby metal objects, e.g., a desk on which the PAN receiver is supported. Moreover, a multiple-electrode PAN transmitter reduces the deleterious effects on the signal from the PAN transmitter that can otherwise be caused by, e.g., loose metal coins that are present in a pocket in which the transmitter is carried.