Patent ID: 6201510
Filing Date: 2001-03-13
Classification: H01Q

Abstract:
A four-dipole element, double tuned for reception at two GPS frequencies and including a progressive-phase-omnidirectional excitation network, comprising:first, second, third and fourth dipoles successively spaced around a vertical axis and each having two opposed arms;a signal port; anda progressive-phase-omnidirectional (PPO) excitation network, coupled between the signal port and the four dipoles, including:(a) a first quadrature coupler coupled between the first and second dipoles to provide first dipole excitation of a first phase and to provide second dipole excitation of a quadrature phase,(b) a second quadrature coupler coupled between the third and fourth dipoles to provide third dipole excitation of a phase differing by 180 degrees from said first phase and to provide fourth dipole excitation of a quadrature phase differing by 180 degrees from the second dipole excitation, and(c) first and second transmission line sections respectively coupled between the signal port and the first and second quadrature couplers; andfour resonant circuits, one coupled to each dipole to provide double tuning for signal reception at two GPS frequencies, each said resonant circuit including the combination of an inductive stub, comprising a gap between the two arms of a dipole, and a capacitive stub, comprising a line section overlying a dipole portion.