Patent ID: 7667660

Claim:
A scanning antenna, comprising: an antenna element having an evanescent coupling portion with a selectively variable coupling geometry; and a waveguide assembly, comprising: a transmission line through which an electromagnetic signal is transmitted, wherein the transmission line defines an axis, and wherein the transmission line is located adjacent the evanescent coupling portion of the antenna element so as to permit evanescent coupling of an electromagnetic signal between the transmission line and the antenna element; and first and second substantially parallel conductive waveguide plates disposed on opposite sides of the transmission line, each of the plates defining a plane that is substantially parallel to the axis defined by the transmission line each of the plates having a proximal end adjacent the antenna element, and a distal end remote from the antenna element; whereby the electromagnetic signal coupled between the transmission line and the antenna element propagates as a beam that is substantially confined to a space defined between the first and second plates, whereby the beam is in a plane that is substantially parallel to the planes defined by the first and second plates.