An antenna comprises first and second radiating elements for connecting to a first and second potential levels respectively. The first and second potential levels are substantially different for generating an electrostatic field from the first and the second radiating elements. The antenna further comprises first and second field shaping structures for controlling field propagation in a first and second direction respectively. The first and second field shaping structures are interdisplaced for defining a field pathway while the first and second radiating elements are disposed adjacent to the first and second field shaping structures and along the field pathway for directing the electrostatic field in a propagation direction through a liquid medium. More specifically, the propagation direction is defined by the field pathway and substantially perpendicular to at least one of the first and second directions.