Patent ID: 6653987
Filing Date: 2003-11-25
Classification: H01Q

Abstract:
A dual-band quadrifilar helix antenna, comprisingfour helical radiating elements each having an upper portion and a lower portion and a gap therebetween, each upper portion having an open end, and each lower portion having a feed point for receiving feed signals in phase quadrature; four traps, one corresponding trap each disposed in the gap and electrically connected to the upper portion and lower portion of a corresponding one of the four radiating elements equidistant from the corresponding open end, the traps configured to have a first impedance at a first frequency, and a second impedance greater than the first impedance, at a second frequency; and at least one feed network providing 0Â°, 90Â°, 180Â° and 270Â° signals to the feed points.