Orthogonal mode transducer having interface plates at the junction of the waveguides

An orthogonal mode transducer comprising:

• a square central waveguide having a first substantially planar end and a second end having first and second planar openings perpendicular to one another wherein said square central waveguide is capable of propagating signals having first and second orthogonal polarizations;
• a first rectangular waveguide coupled to said first planar opening in the second end of said square central waveguide, said first rectangular waveguide being capable of propagating a signal having said first polarization but not a signal having said second polarization;
• and
• a second rectangular waveguide coupled to the second planar opening in the second end of said square central waveguide, said second rectangular waveguide being capable of propagating a signal having said second polarization but not a signal having said first polarization,
• wherein the first and second planar openings are arranged so that the longitudinal axes of the first and second rectangular waveguides will be symmetrical relative to the longitudinal axis of the central square waveguide to thereby form a symmetrical Y-configuration, and
• wherein the length of the sides of the square central waveguide is smaller than the length of the broad sides of the first and second rectangular waveguides but larger than the length of the narrow sidewalls of the first and second rectangular waveguides, and
• further comprising interface plates between the ends of the first and second rectangular waveguides and the first and second planar openings in the second end of the square central waveguide to match the rectangular open ends to the planar openings, said interface plates including openings to permit the passage of signals between the square and rectangular waveguides.

A method of combining first and second signals which are orthogonally polarized relative to one another comprising:

• propagating said first signal along a first rectangular waveguide which is not capable of propagating the second signal due to its polarization;
• propagating said second signal along a second rectangular waveguide which is not capable of propagating the first signal due to its polarization;
• and
• combining said first and second signals to form a composite third signal having both of the orthogonal polarizations of the first and second signals in a common central square waveguide to which said first said second rectangular waveguides are coupled in such a manner that the longitudinal axes of the first and second rectangular waveguides are symmetrically arranged relative to the longitudinal axis of the central waveguide to form a symmetrical Y-configuration,
• wherein substantially flat interface plates having length and width dimensions at least as great as lengths of respective sides of the rectangular waveguides are coupled between the rectangular waveguides and the square waveguide at the point where the respective waveguides are coupled together to match the size of the openings at the ends of the rectangular waveguides with the size of the opening at an end of the square waveguide, said interface plates including openings to permit passage of signals between the square and rectangular waveguides.

A method of separating first and second orthogonal signal components from a composite third signal containing said orthogonal first and second signal components, comprising:

• propagating said composite signal along a common central square waveguide capable of carrying both said first and second orthogonal signal components;
• and
• separating said first and second orthogonal signal components from one another by coupling the composite signal into a junction formed by said common central waveguide and first and second rectangular waveguides which are coupled to said common central waveguide such that the longitudinal axes of the first and second rectangular waveguides are symmetrically arranged relative to the longitudinal axis of the central waveguide to form a symmetrical Y-configuration, wherein the first rectangular waveguide is configured to be capable of carrying the first orthogonal signal component but not the second orthogonal signal component and the second rectangular waveguide is configured to be capable of carrying the second orthogonal signal component but not the first orthogonal signal component,
• wherein substantially flat interface plates having length and width dimensions at least as great as lengths of respective sides of the rectangular waveguides are coupled between the rectangular waveguides and the square waveguide at the point where the respective waveguides are coupled together to match the size of the openings at the ends of the rectangular waveguides with the size of the opening at an end of the square waveguide, said interface plates including openings to permit passage of signals between the square and rectangular waveguides.

A method of separating transmitted signals from received signals, propagating along a common central square waveguide, wherein the transmitted signals are polarized orthogonally with respect to the received signals, comprising:

• propagating the transmitted signals along a first rectangular waveguide capable of supporting the polarization of the transmitted signal but not the polarization of the received signal, and coupling said transmitted signal from said first rectangular waveguide into a first end of the common central waveguide for transmission from a second end of said common central waveguide;
• and
• receiving said received signals in said second end of said common central waveguide and coupling them into a second rectangular waveguide which is capable of supporting the polarization of the received signal but not the polarization of the transmitted signal, said second rectangular waveguide being coupled to said first end of said common central waveguide such that the longitudinal axes of the first and second rectangular waveguides are symmetrically arranged relative to the longitudinal axis of the central waveguide to form a symmetrical Y-configuration,
• wherein substantially flat interface plates having length and width dimensions at least as great as lengths of respective sides of the rectangular waveguides are coupled between the rectangular waveguides and the square waveguide at the point where the respective waveguides are coupled together to match the size of the openings at the ends of the rectangular waveguides with the size of the opening at an end of the square waveguide, said interface plates including openings to permit passage of signals between the square and rectangular waveguides.