US Patent 7173576 Handset quadrifilar helical antenna mechanical structures

A quadrifilar helical antenna comprising two pairs of filars having unequal lengths and phase quadrature signals propagating thereon. A disk-like impedance matching element disposed at a lower end of the antenna matches a source impedance to an antenna impedance. In certain embodiments a first crossbar connector on a substrate disposed at an upper end of the antenna electrically connects two helical filars to form a first filar pair and a second crossbar connector disposed on the substrate connects two filars to form a second filar pair.