Differential attenuator having a zero net differential phase-shift

Claim 2

A microwave differential attenuator comprising: a section of conductively bounded waveguide; a first means for increasing the attenuation constant and phase constant of said guide along a first polarization direction relative to an orthogonal polarization direction; and a second means for increasing the phase constant of said guide along said orthogonal polarization direction relative to said first polarization direction by an amount which results in said phase constant in said orthogonal polarization direction being equal to said increased phase constant in said first polarization direction.

Claim 3

A differential attenuator in accordance with claim 1 in which the increase in said phase constant along said polarization directions is equal.

Claim 4

A differential attenuator in accordance with claim 1 in which said first means comprises a lossy dielectric member having a dielectric constant greater than 1 and in which said second means comprises a nonlossy dielectric member having a dielectric constant greater than 1.

Claim 5

A microwave differential attenuator comprising: a section of conductively bounded waveguide; first means disposed within said waveguide for producing a differential attenuation and a differential phase-shift along first and second orthogonal directions; and second means disposed within said waveguide for producing a differential phase-shift along said directions which is opposite in sense to that produced by said first means and which has a magnitude which results in a substantially zero net differential phase-shift along said directions.

Claim 6

A microwave differential attenuator comprising: a section of conductively bounded waveguide; first means disposed within said waveguide for producing a differential attenuation and a differential phase-shift along first and second orthogonal directions; and second means disposed within said waveguide for producing a differential phase-shift along said directions which is opposite in sense to that produced by said first means and which has a magnitude which results in a substantially zero net differential phase-shift along said directions.

Claim 7

A differential attenuator in accordance with claim 4 in which the said first and second means produce differential phase-shifts of equal magnitude.

Claim 8

A differential attenuator for providing a differential attenuation to waves having first and second orthogonal polarization directions comprising: a section of conductively bounded waveguide having its axis orthogonal to each of said first and second polarization directions; a pair of lossy dielectric vanes symmetrically disposed within said waveguide with respect to the axis thereof, each of said vanes having a dielectric constant greater than 1 and each being arranged in a plane parallel to the plane defined by said first polarization direction and said axis, said vanes being such as to induce an increase in the attenuation constant and the phase constant of said waveguide along said first polarization direction relative to said second polarization direction; and a pair of nonlossy dielectric vanes disposed symmetrically within said waveguide with respect to the axis thereof, each of said vanes having a dielectric constant greater than 1 and Each being arranged in a plane which is orthogonal to the planes of said lossy vanes, said nonlossy vanes being such as to induce an increase in the phase constant of said waveguide along said second polarization direction relative to said first polarization direction by an amount for which said phase constant in said second polarization direction is made equal to said increased phase constant in said first polarization direction.

Claim 9

A differential attenuator for providing a differential attenuation to waves having first and second orthogonal polarization directions comprising: a section of conductively bounded waveguide having its axis orthogonal to each of said first and second polarization directions; a pair of lossy dielectric vanes symmetrically disposed within said waveguide with respect to the axis thereof, each of said vanes having a dielectric constant greater than 1 and each being arranged in a plane parallel to the plane defined by said first polarization direction and said axis, said vanes being such as to induce an increase in the attenuation constant and the phase constant of said waveguide along said first polarization direction relative to said second polarization direction; and a pair of nonlossy dielectric vanes disposed symmetrically within said waveguide with respect to the axis thereof, each of said vanes having a dielectric constant greater than 1 and Each being arranged in a plane which is orthogonal to the planes of said lossy vanes, said nonlossy vanes being such as to induce an increase in the phase constant of said waveguide along said second polarization direction relative to said first polarization direction by an amount for which said phase constant in said second polarization direction is made equal to said increased phase constant in said first polarization direction.

Claim 10

A differential attenuator in accordance with claim 6 in which said guide has a circular cross section.

Claim 11

A differential attenuator in accordance with claim 6 in which each of said vanes has a thickness smaller than its width and a width smaller than its length and in which said lossy vanes are arranged with their lengths parallel to said axis and their widths parallel to said first polarization direction, and said nonlossy vanes are arranged with their lengths parallel to said axis and their widths parallel to said second polarization direction.

Claim 12

a differential attenuator in accordance with claim 6 which includes, in addition: support means for movably supporting each of said vanes within said guide; and means for moving each of said vanes within said guide.

Claim 13

A differential attenuator in accordance with claim 9 in which said vanes are simultaneously moved in the same sense relative to the guide axis.

Claim 14

A differential attenuator in accordance with claim 9 in which there are a plurality of apertures in the waveguide wall adjacent to each of said vanes and in which said support means comprises first, second, third and fourth pluralities of rodlike members, the rodlike members of each of said pluralities being affixed to one of said vanes and slidably mounted in the apertures adjacent to that one vane.

Claim 15

A differential attenuator in accordance with claim 11 in which said means for moving comprises a rotatable housing into which said guide is inserted, said housing having an inner surface facing said guide including four camlike surfaces, each of said camlike surfaces being in contact with the plurality of rodlike members associated with one of said vanes.