Low dielectric, low loss radome
A low dielectric, low loss radome comprising microspheres integrated into a matrix. The microspheres reduce overall dielectric constant, whereby the radome has a dielectric constant less than 2.5 through a thickness of the radome.
1 . A low dielectric, low loss radome comprising low dielectric constant, low loss filler integrated into a matrix, the low dielectric constant, low loss filler reducing overall dielectric constant, wherein the low dielectric constant, low loss filler is distributed throughout the matrix such that the radome exhibits a substantially uniform dielectric of less than 2.5 through an entire thickness of the radome at frequencies from about 20 GHz to about 90 GHz.
2 . The radome of claim 1 , further comprising fibers, and wherein the fibers and the low dielectric constant, low loss filler are co-integrated into the matrix such that the radome has a homogenous and/or unitary structure that is thermoformable prior to cure.
3 . The radome of claim 2 , wherein the homogenous and/or unitary structure is a single layer structure.
4 . The radome of claim 1 , wherein the radome comprises first and second thermoplastic layers and a thermoplastic core between the first and second thermoplastic layers, whereby the radome is thermoformable, wherein:
the thermoplastic core comprises a thermoplastic foam or a thermoplastic honeycomb; and
the first and second thermoplastic layers comprise the low dielectric constant, low loss filler integrated into the matrix.
5 . The radome of claim 4 , wherein:
the first and second thermoplastic layers further comprise fibers integrated into the first and second thermoplastic layers for reinforcement and mechanical strength; and
the low dielectric constant, low loss filler is integrated into the first and second thermoplastic layers and reduce the overall dielectric constant of the radome, whereby the first and second thermoplastic layers each have a dielectric constant of about 2.8 or less.
6 . The radome of claim 1 , wherein:
the matrix comprises an injection moldable resin; and
the radome is an injection molded radome configured to have an overall dielectric constant within a range from about 1.5 to about 2.5 and an overall low loss tangent or dissipation factor (Df) less than about 0.01 at frequencies from about 20 GHz to about 90 GHz and/or from about 20 GHz to about 50 GHz and/or from about 24 GHz to about 40 GHz.
7 . The radome of claim 1 , wherein:
the matrix comprises an injection moldable resin; and/or
the matrix comprises polypropylene; and/or
the matrix comprises a blend of polycarbonate and polybutylene terephthalate.
8 . The radome of claim 1 , further comprising fibers within the matrix, wherein:
the fibers comprise one or more of flame-resistant meta-aramid material, open weave polymeric fabric, high-density polyethylene, ultra-high molecular weight polyethylene, high density plastic fibers with a low dielectric constant, and/or high density polypropylene fibers; and
the low dielectric constant, low loss filler comprises one or more of hollow glass microspheres, hollow plastic microspheres, hollow ceramic microspheres, microballoons, and/or bubbles.
9 . The radome of claim 1 , further comprising fibers, and wherein the fibers and the low dielectric constant, low loss filler is integrated into the matrix such that the radome does not have outer and inner skin layers disposed on opposite sides of a core that define a three-layer A-sandwich structure.
10 . The radome of claim 1 , further comprising flame retardant applied to and/or integrated into at least a portion of the radome such that the radome has a UL94 flame rating of V0.
11 . The radome of claim 1 , further comprising fibers within the matrix for reinforcement and mechanical strength.
12 . The radome of claim 1 , wherein the radome is configured to be anisotropic and/or configured to reduce cross polarization differences between horizontal and vertical polarizations.
13 . The radome of claim 1 , wherein the radome is configured to have:
a dielectric constant of about 2 or less at frequencies from about 20 GHz to about 90 GHz; and/or
a dielectric constant of about 1.85 or less at frequencies from about 20 GHz to about 50 GHz; and/or
a dielectric constant of about 1.7 or less at frequencies from about 24 GHz to about 40 GHz.
14 . The radome of claim 1 , wherein the low dielectric constant, low loss filler comprises microspheres.
15 . The radome of claim 14 , wherein the microspheres comprise one or more of hollow glass microspheres, hollow plastic microspheres, hollow ceramic microspheres, microballoons, and/or bubbles.
16 . The radome of claim 1 , wherein the low dielectric constant, low loss filler comprises microballoons.
17 . The radome of claim 1 , wherein the low dielectric constant, low loss filler comprises bubbles.
18 . The radome of claim 1 , wherein:
the low dielectric constant, low loss filler comprises microspheres that are distributed throughout the matrix such that the radome exhibits the substantially uniform dielectric constant of less than 2.5 across the entire thickness of the radome at frequencies from about 20 GHz to about 90 GHz; and
the radome is configured to minimize signal reflection at an incident surface by avoiding discrete high-dielectric skin layers.
19 . The radome of claim 1 , wherein:
the low dielectric constant, low loss filler comprises bubbles that are distributed throughout the matrix such that the radome exhibits the substantially uniform dielectric constant of less than 2.5 across the entire thickness of the radome at frequencies from about 20 GHz to about 90 GHz; and
the radome is configured to minimize signal reflection at an incident surface by avoiding discrete high-dielectric skin layers.
20 . The radome of claim 1 , wherein:
the low dielectric constant, low loss filler comprises microballoons that are distributed throughout the matrix such that the radome exhibits the substantially uniform dielectric constant of less than 2.5 across the entire thickness of the radome at frequencies from about 20 GHz to about 90 GHz; and
the radome is configured to minimize signal reflection at an incident surface by avoiding discrete high-dielectric skin layers.
21 . The radome of claim 1 , wherein the radome is configured to minimize signal reflection at an incident surface by avoiding discrete high-dielectric skin layers.
22 . A low dielectric, low loss radome comprising first and second layers and a core between the first and second layers, wherein:
each of the first and second layers comprise low dielectric constant, low loss filler integrated into a matrix; and
the first layer, the core, and the second layer cooperate to provide a substantially uniform effective dielectric constant of less than 2.5 through a thickness of the radome.
23 . The radome of claim 22 , wherein:
the first and second layers further comprise fibers integrated into the first and second layers for reinforcement and mechanical strength; and
the low dielectric constant, low loss filler is integrated into the first and second layers and reduce the overall dielectric constant of the radome, whereby the first and second layers each have a dielectric constant of about 3.6 or less.
24 . The radome of claim 22 , wherein the core comprises:
a thermoplastic honeycomb core having a dielectric constant of about 1.03 or less;
honeycomb cells of the thermoplastic honeycomb core remain substantially open such that the dielectric constant is not increased by pore-filling resin;
honeycomb cell walls are coated with flame retardant at a thickness insufficient to occlude the honeycomb cells; and
the low dielectric constant, low loss filler comprises microspheres including one or more of hollow glass microspheres, hollow plastic microspheres, hollow ceramic microspheres, microballoons, and/or bubbles.
25 . The radome of claim 22 , wherein
the core comprises a thermoset core such that the radome is thermoformed and cured.
26 . The radome of claim 22 , wherein the radome comprises:
a partially cured B-stage material configured to be formed or shaped in three dimensions and fully cured; and/or
a B-staged epoxy resin including fabric and/or fibers embedded therein.
27 . A material for a low dielectric, low loss radome, the material comprising low dielectric constant, low loss filler integrated into a matrix, the low dielectric constant, low loss filler reducing overall dielectric constant, wherein the low dielectric constant, low loss filler is distributed throughout the matrix such that the material exhibits a substantially uniform dielectric of less than 2.5 through an entire thickness of the material at frequencies from about 20 GHz to about 90 GHz.
28 . The material of claim 27 , wherein the low dielectric constant, low loss filler comprises one or more of hollow glass microspheres, hollow plastic microspheres, hollow ceramic microspheres, microballoons, and/or bubbles; and wherein:
the matrix comprises an injection moldable resin, polypropylene, and/or a blend of polycarbonate and polybutylene terephthalate; and/or
the material comprises fibers within the matrix, the fibers comprising one or more of flame-resistant meta-aramid material, open weave polymeric fabric, high-density polyethylene, ultra-high molecular weight polyethylene, high density plastic fibers with a low dielectric constant, and/or high density polypropylene fibers.
29 . The material of claim 27 , further comprising flame retardant applied to and/or integrated into the material such that the material has a UL94 flame rating of V0, and wherein the material is configured to have:
a dielectric constant of about 2 or less at frequencies from about 20 GHz to about 90 GHz; and/or
a dielectric constant of about 1.85 or less at frequencies from about 20 GHz to about 50 GHz; and/or
a dielectric constant of about 1.7 or less at frequencies from about 24 GHz to about 40 GHz.
30 . The material of claim 27 , wherein the low dielectric constant, low loss filler comprises microspheres.
31 . The material of claim 30 , wherein the microspheres comprise one or more of hollow glass microspheres, hollow plastic microspheres, hollow ceramic microspheres, microballoons, and/or bubbles.
32 . The material of claim 27 , wherein the low dielectric constant, low loss filler comprises microballoons.
33 . The material of claim 27 , wherein the low dielectric constant, low loss filler comprises bubbles.
34 . The material of claim 27 , wherein:
the low dielectric constant, low loss filler comprises microspheres, bubbles, and/or microballoons that are distributed throughout the matrix such that the material exhibits the substantially uniform dielectric constant of less than 2.5 across the entire thickness of the material at frequencies from about 20 GHz to about 90 GHz; and
the material is configured to minimize signal reflection at an incident surface by avoiding discrete high-dielectric skin layers.
35 . The material of claim 27 , wherein the material is configured to minimize signal reflection at an incident surface by avoiding discrete high-dielectric skin layers.