Duo-quad wideband waveguide combiner/mode-converter transforming two rectangular waveguides in the TE10 rectangular mode to a single circular waveguide output in the TE01 mode

A power combiner for combining radio frequency signals from two inputs into a combined output signal at an output having a TE01 circular mode comprising:

• a first rectangular waveguide having a TE10 rectangular mode, the first rectangular waveguide having a thin septum to bifurcate the first rectangular waveguide into two bifurcated waveguides, each one of the two bifurcated waveguides of the first rectangular waveguide transitions from a rectangular cross section to a cross section resembling a pie slice spanning one quadrant of a composite circular cross section;
• a second rectangular waveguide having a TE10 rectangular mode, the second rectangular waveguide having a thin septum to bifurcate the second rectangular waveguide into two bifurcated waveguides, each one of the two bifurcated waveguides of the second rectangular waveguide transitions from a rectangular cross section to a cross section resembling a pie slice spanning one quadrant of a composite circular cross section;
• and
• a circular waveguide having TE01 circular mode, the circular waveguide disposed at converging walls of each one of the quadrants of the composite circular cross section which form a thin septa between each one of the quadrants.

A method of providing a power combiner for combining two TE10 rectangular mode microwave signals into a combined output TE01 circular mode microwave signal comprising:

• providing a metallic plate having a first rectangular opening and a second rectangular opening, each opening accommodating a rectangular waveguide as an input to the power combiner, the first rectangular opening bifurcated by a first thin septum to split the first rectangular waveguide into a first bifurcated waveguide and a second bifurcated waveguide, the second rectangular opening bifurcated by a second thin septum to split the second rectangular waveguide into a third bifurcated waveguide and a fourth bifurcated waveguide;
• providing a first metallic layer having a first side and a second side with four openings, each of the four openings on the first side mating with a respective bifurcated waveguide of the first, second, third or fourth bifurcated waveguides in the metallic plate, each of the four opening partially rotates to a respective quadrant about a center axis of a circular output and transitions from a rectangular cross-section to a cross-section resembling a pie slice spanning one quadrant of a composite circular cross section of circular waveguide;
• providing a second metallic layer having a first side and a second side with four openings, each of the four openings on the first side mating with a respective opening in the second side of the first metallic layer, each of the four opening partially rotates to a respective quadrant about a center axis of a circular output and transitions from a rectangular cross-section to a cross-section resembling a pie slice spanning one quadrant of a composite circular cross section of circular waveguide;
• providing successive layers having a first side and a second side with four openings, each of the four openings on the first side mating with a respective opening in the second side of an adjacent metallic layer, each of the four opening partially rotates to a respective quadrant about a center axis of a circular output until a transition from a rectangular cross-section to a cross-section resembling a pie slice spanning one quadrant of a composite circular cross section of circular waveguide is completed;
• and
• providing a ring with an aperture disposed adjacent the successive layer having a completed composite circular cross section, the aperture sized to match the circular cross section in the successive layer and providing the output of the power combiner.