The present invention concerns application of a unique conductive electrode geometry used to form an efficient wideband, one- or two-way wireless data link between autonomous systems separated by some distance along a bore hole drill string. One objective is the establishment of an efficient, high bandwidth communication link between such separated systems, using a unique electrode configuration that also aids in maintaining a physically robust drill string. Insulated or floating electrodes of various selected geometries provide a means for sustaining or maintaining a modulated electric potential adapted for injecting modulated electrical current into the surrounding sub-surface medium. Such modulated current conveys information to the systems located along the drill string by establishing a potential across a receiving insulated or floating electrode.