Recent theoretical developments have defined the conditions for forming a broadband beam that is narrow in axial extent but extended in range. The formulation is based on the classical angular spectrum decomposition and the requirement for arranging all spatial and temporal frequencies such that all components have constant phase propagation between planes. Analytic formulations are given for a 1-D source and a 2-D axisymmetric source, and comparisons are made against conventional focused Gaussian beams under similar conditions relevant to medical imaging systems.