Improved radiofrequency antenna

A radiofrequency collinear microstrip patch antenna to be driven by an external source, the antenna comprising a substantially electrically insulating substrate being longer along an axis than its width substantially perpendicular to the axis, the substrate having at least two face portions in different geometric planes, the antenna comprising at least one element of electrical conductor on each of the at least two face portions of the substrate along an axis of the substrate, each element comprising one or more portions of relatively narrower width and one or more portions of relatively wider width, each portion being approximately a same length as one another, wherein at least one portion of relatively narrower width of one element on one face portion of the substrate substantially corresponds along the axis of the substrate with at least one portion of relatively wider width of another element on another face portion of the substrate, and wherein at least one portion of relatively wider width of one element comprises a zone of conductor which is substantially contiguous across a width of the portion of relatively wider width and at least one tapered region along the axis, the tapered region overlapping along the axis of the substrate with at least one portion of relatively narrower width of another element, and wherein the or each tapered region forms an approximately concave end to the portion such that the portion of relatively wider width is longer along the axis towards a side of the substrate than towards the axis of the substrate, and wherein the antenna is adapted to be driven from one end thereof only.