United States of America As Represented by the Administrator of Nasa

Johns Hopkins University

David T Chuss

Edward J Wollack

Samuel H Moseley

Kongpop U-Yen

Giles A Novak

Charles L Bennett

Lingzhen Zeng

Kevin L Denis

Karwan Rostem

A phononic filter includes a metamaterial body including a membrane including a crystalline or amorphous dielectric material, an elemental superconductor or an alloyed superconductor; and a plurality of spaced features. The spaced features includes holes, spacings, or apertures in the metamaterial body.

Two-dimensional phononic metamaterial filter structure for ultra-low-background detectors

A photonic waveguide choke includes a first waveguide flange member having periodic metal tiling pillars, a dissipative dielectric material positioned within an area between the periodic metal tiling pillars and a second waveguide flange member disposed to be coupled with the first waveguide flange member and in spaced-apart relationship separated by a gap. The first waveguide flange member has a substantially smooth surface, and the second waveguide flange member has an array of two-dimensional pillar structures formed therein.

Photonic waveguide choke joint with absorptive loading

A device for at least one of receiving and transmitting electromagnetic radiation includes a feedhorn having a substantially smooth, electrically conducting inner surface extending from an open end to a feed end, the inner surface being substantially rotationally symmetrical about a longitudinal axis, wherein an orthogonal distance from a point on the longitudinal axis to the substantially smooth, electrically conducting inner surface increases monotonically as the point on the longitudinal axis is selected at successively greater distances from the feed end of the feedhorn towards the open end of the feedhorn such that a profile of the substantially smooth, electrically conducting inner surface of the feedhorn is monotonically increasing. The feedhorn has an operating bandwidth and the feedhorn provides a maximum of &#x2212;30 dB cross polarization response over at least 15% of the operating bandwidth. A method of producing a feedhorn for receiving or transmitting electromagnetic radiation includes determining a profile of an inner surface of the feedhorn based on constraints required to achieve a plurality of operating parameters, providing a pre-machined feedhorn having an initial inner surface, and machining the initial inner surface of the pre-machined feedhorn to substantially match the profile determined to achieve the plurality of operating parameters for the feedhorn. The determining the profile includes a constraint for the profile to be a monotonically increasing profile relative to a rotational symmetry axis of the inner surface of the feedhorn going from a narrow end to a wide end of the feedhorn.

Smooth-walled feedhorn

A waveguide choke joint includes a first array of pillars positioned on a substrate, each pillar in the first array of pillars having a first size and configured to receive an input plane wave at a first end of the choke joint. The choke joint has a second end configured to transmit the input plane wave away from the choke joint. The choke joint further includes a second array of pillars positioned on the substrate between the first array of pillars and the second end of the choke joint. Each pillar in the second array of pillars has a second size. The choke joint also has a third array of pillars positioned on the substrate between the second array and the second end of the choke joint. Each pillar in the third array of pillars has a third size.

Photonic waveguide choke joint with non-absorptive loading

A device for at least one of receiving and transmitting electromagnetic radiation includes a feedhorn having a substantially smooth, electrically conducting inner surface extending from an open end to a feed end, the inner surface being substantially rotationally symmetrical about a longitudinal axis, wherein an orthogonal distance from a point on the longitudinal axis to the substantially smooth, electrically conducting inner surface increases monotonically as the point on the longitudinal axis is selected at successively greater distances from the feed end of the feedhorn towards the open end of the feedhorn such that a profile of the substantially smooth, electrically conducting inner surface of the feedhorn is monotonically increasing. The feedhorn has an operating bandwidth and the feedhorn provides a maximum of &#x2212;30 dB cross polarization response over at least 15% of the operating bandwidth.

A waveguide structure for a dual polarization waveguide includes a first flange member, a second flange member, and a waveguide member disposed in each of the first flange member and second flange member. The first flange member and the second flange member are configured to be coupled together in a spaced-apart relationship separated by a gap. The first flange member has a substantially smooth surface, and the second flange member has an array of two-dimensional pillar structures formed therein.

Photonic choke-joints for dual polarization waveguides

A signal conditioning module provides a polarimeter capability in a photometric system. The module may include multiple variable delay polarization modulators. Each modulator may include an input port, and a first arm formed to include a first reflector and first rooftop mirror arranged in opposed relationship. The first reflector may direct an input radiation signal to the first rooftop mirror. Each modulator also may include an output port and a second arm formed to include a second reflector and second rooftop mirror arranged in opposed relationship. The second reflector can guide a signal from the second rooftop mirror towards the output port to provide an output radiation signal. A beamsplitting grid may be placed between the first reflector and the first rooftop mirror, and also between the second reflector and the second rooftop mirror. A translation apparatus can provide adjustment relative to optical path length vis-&#xe0;-vis the first arm, the second arm and the grid.

Interferometric polarization control

A signal conditioning module provides a polarimeter capability in a photometric system. The module may include multiple variable delay polarization modulators. Each modulator may include an input port, and a first arm formed to include a first reflector and first rooftop mirror arranged in opposed relationship. The first reflector may direct an input radiation signal to the first rooftop mirror. Each modulator also may include an output port and a second arm formed to include a second reflector and second rooftop mirror arranged in opposed relationship. The second reflector can guide a signal from the second rooftop mirror towards the output port to provide an output radiation signal. A beamsplitting grid may be placed between the first reflector and the first rooftop mirror, and also between the second reflector and the second rooftop mirror. A translation apparatus can provide adjustment relative to optical path length vis-a-vis the first arm, the second arm and the grid.

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Bowie, MD, United States of America

David T Chuss