Passive intermodulation shield
AssigneeHughes Aircraft Company
InventorsRobert L. Reynolds, Jodi L. Larson, Judy V. May
Life of this patent
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Abstract
A passive intermodulation shield (10) for a spacecraft is made from a substrate (12) and a vacuum deposited aluminum layer (14) over the substrate (12). The substrate (12) can include a polyimide sheet such as Kapton. The vacuum deposited aluminum layer (14) has a thickness (16) to produce a surface resistivity which maintains both the inherent passive intermodulation generation and the passive intermodulation passthrough below a predetermined value. Preferably, the surface resistivity is selected between 10 ohms per square and 40 ohms per square. Spacecraft multilayer insulation blankets (30, 40, 50, 60) are formed by disposing the passive intermodulation shield (10) between a pair of outer layers.
Claims20
A passive intermodulation shield comprising:
- a substrate;
- and
- a conducting layer deposited over the substrate to produce a surface resistivity between 2 ohms per square and 200 ohms per square;
- wherein the surface resistivity is greater than 2 ohms per square to limit an amount of inherent passive intermodulation generation, and wherein the surface resistivity is less than 200 ohms per square to limit an amount of passive intermodulation passthrough.
A passive intermodulation shield for a spacecraft, the passive intermodulation shield comprising:
- a Kapton substrate;
- and
- a vacuum deposited aluminum layer over the substrate, the vacuum deposited aluminum layer having a thickness to produce a surface resistivity between 10 ohms per square and 40 ohms per square to maintain both an inherent passive intermodulation generation and a passive intermodulation passthrough to be below -55 dB.
A blanket for protecting a spacecraft from a space environment comprising:
- a pair of outer layers;
- and
- a passive intermodulation shield disposed between the pair of outer layers, the passive intermodulation shield having a conducting layer deposited over a substrate to produce a surface resistivity between 2 ohms per square and 200 ohms per square;
- wherein the surface resistivity is greater than 2 ohms per square to limit an amount of inherent passive intermodulation generation, and wherein the surface resistivity is less than 200 ohms per square to limit an amount of passive intermodulation passthrough.
Dependencies are inferred from the claim text.