Patent ID: 8264417

Claim:
An antenna structure comprising: a first antenna element comprising an elongate channel having an internal conductive surface and an apertured proximal end spaced apart from, and flaring out to, an apertured distal end, said conductive surface providing a propagation path, and said proximal end receiving EM waves in a first EM radiation pattern; a second antenna element positioned at least partially within said first antenna element, said second antenna element having a proximal portion coupled to a distal portion, said proximal portion flaring out from a proximal portion proximal end having a first cross-sectional area to proximal portion distal end having a second cross-sectional area larger than said first cross-sectional area, and said distal portion having a distal portion proximal end coupled to said proximal portion distal end and flaring in towards said apertured distal end, and said second antenna element introducing a phase delay along said propagation path adapted to at least partially flatten a phase front of said first EM radiation pattern to produce a second EM radiation pattern; and a third antenna element adapted to output said EM waves, wherein said second antenna element extends into said third antenna element; wherein said proximal portion proximal end extends at least to said apertured proximal end of said first antenna element.