Systems and methods for improving an efficiency and a gain of a helical antenna. The methods comprise: configuring a conductive helix element of the helical antenna to comprise a proximal segment having a helical winding that extends along an axis of the conductive helix element and has a plurality of turns with linearly progressing pitch angles; configuring the conductive helix element to comprise a distal segment having a helical winding that extends along the axis of the conductive helix element and has a constant pitch angle; and coupling the distal segment to the proximal segment in a series arrangement so that a radio wave reaches a terminal velocity at a point of the coupling.