| abstract |
A printed quasi-tapered tape helical element and printed helical array antenna arc disclosed. The helical element comprises a thin helix conductor having a uniform section associated with a tapered section. The helix conductor can be printed on a thin dielectric sheet and bonded to a hollow composite dielectric support. A solid copper conductor is configured to provide electrical connection between a feeding point of the helix conductor and a microstrip line of a microstrip feed network. The uniform and tapered helix turns are respectively wrapped around the uniform and tapered sections, which enables impedance matching, axial mode excitation, gain and radiation patterns, and damping out of standing waves generated in current distribution over the helix conductor. Conductive composite cups surrounding each helical element reduces mutual coupling in array environment. Thus, the helical element and the array antenna achieve low on-axis and off-axis axial ratio performance over the wideband for global coverage. |