Circularly polarized antenna system using a combination of turnstile and vertical dipole radiators

A circularly polarized antenna system for operation over a relatively broad band of frequencies comprising:

• a vertically oriented support tower,
• four radiating planar elements mounted about the tower at 90.degree. intervals with each of the planar elements including a grid of conductors extending perpendicular from the tower in a given plane over a vertical length of approximately one half wavelength at a frequency within said broad band of frequencies and configured to excite horizontally polarized fields,
• means for feeding signal energy at a first power level to said four planar elements with equal power to each radiating planar element and in relative phase rotation of 0.degree., 90.degree., 180.degree. and 270.degree. in the manner of a turnstile,
• four vertically oriented dipoles mounted to the tower with a vertically oriented dipole spaced vertically a given distance from each radiating planar element,
• means for feeding equal signal energy to each of said four vertically oriented dipoles in relative phase rotation of 0.degree., 90.degree., 180.degree. and 270.degree.,
• said four vertically oriented dipoles being spaced from each other and fed in an amplitude and phase relationship with respect to the signal energy fed to said four radiating planar elements to cause the horizontal pattern of the vertically polarized field associated with the vertical dipoles to be of similar shape and magnitude and in phase quadrature to the horizontal pattern of the horizontally polarized field associated with the four radiating planar elements.

A circularly polarized antenna system comprising:

• a vertically oriented support tower,
• four radiating elements mounted about the tower at 90.degree. intervals with the elements extending from the tower and configured to excite horizontally polarized fields,
• means for feeding signal energy at a first power level to said four radiating elements with equal power to each radiating element and in relative phase rotation of 0.degree., 90.degree., 180.degree. and 270.degree. in the manner of a turnstile,
• four vertically oriented dipoles mounted to the tower with a vertically oriented dipole spaced vertically a given distance from each radiating element, said vertically oriented dipoles being spaced from each other to cause in the presence of signal energy applied thereto the horizontal pattern of the vertically polarized field associated with the vertically oriented dipoles to be of similar shape to the horizontal pattern of the horizontally polarized field associated with the four radiating elements,
• means for feeding equal signal energy to each of said four vertically oriented dipoles in relative phase rotation of 0.degree., 90.degree., 180.degree. and 270.degree., and in equal amplitude and approximately 90.degree. phase relationship with respect to the signal energy fed to said four radiating elements to cause the horizontal pattern of the vertically polarized field associated with the vertical dipoles to be equal magnitude and in phase quadrature to the horizontal pattern of the horizontally polarized field associated with the four radiating elements.