Patent ID: 6211750
Filing Date: 2001-04-03
Classification: H01P,H01Q

Abstract:
Dual waveguide feed apparatus for conducting radio signals within dual ranges of frequencies including a lowest frequency, the apparatus comprising:an outer conductor having an open end and a rear wall opposite said open end positioned along an axis of the outer conductor and defining a first waveguide cavity within the outer conductor,;a center conductor positioned within said first waveguide cavity and along the axis of said outer conductor, the center conductor defining a second waveguide cavity with a fundamental waveguide mode within the center conductor, the second waveguide cavity being constructed to operate at a first range of frequencies; andsaid center conductor and said outer conductor defining a coaxial waveguide cavity with a fundamental coaxial-waveguide mode within the coaxial waveguide cavity, the coaxial waveguide cavity being constructed to operate at a second range of frequencies different than the first range of frequencies, and the outer conductor being constructed to have a cutoff frequency for the fundamental coaxial-waveguide mode which is at least 95% of the lowest frequency for the apparatus.