FLAT COAXIAL CABLE
A flat coaxial cable is disclosed. The flat coaxial cable can comprise a first ground layer; a second ground layer; a strip-line positioned between the first ground layer and the second ground layer; and a dielectric material positioned between the first ground layer and the second ground layer and surrounding the strip-line to insulate the strip-line from the first ground layer and the second ground layer. The flat coaxial cable can be resistant to a change in the general geometry of a body of the coaxial cable with the application of a perpendicular force to the body.
1 . A flat coaxial cable, comprising:
a first ground layer having a thickness from 10 micrometers (μm) to 100 μm;
a second ground layer having a thickness from 10 μm to 100 μm;
a strip-line positioned vertically between the first ground layer and the second ground layer, and having a thickness from 35 μm to 150 μm; and
a dielectric material, having a thickness from 150 μm to 1500 μm, wherein the dielectric material is positioned vertically between the first ground layer and the second ground layer and surrounding the strip-line to insulate the strip-line from the first ground layer and the second ground layer to form the flat coaxial cable with a thickness, measured from a top of the first ground layer to a bottom of the second ground layer, of less than or equal to 3000 μm.
2 . The flat coaxial cable of claim 1 , wherein the coaxial cable has a bend radius of less than or equal to 5 mm or a bend radius of less than or equal to 2 mm.
3 . The flat coaxial cable of claim 1 , wherein the coaxial cable has a thickness of less than or equal to 1500 μm.
4 . The flat coaxial cable of claim 1 , wherein the strip-line is a conductor comprised of a single wire or a printed conductor on the dielectric material.
5 . The flat coaxial cable of claim 1 , wherein one or more of the first ground layer and the second ground layer are formed of a metal mesh.
6 . The flat coaxial cable of claim 1 , wherein the dielectric material is a polyimide film.
7 . The flat coaxial cable of claim 1 , wherein the dielectric material is comprised of a plurality of layers of a polyimide film.
8 . The flat coaxial cable of claim 1 , further comprising a radio frequency coupler electrically coupled to the first ground layer, the second ground layer, and the strip line at each end of the flat coaxial cable.
9 . The flat coaxial cable of claim 1 , wherein the flat coaxial cable has a length from 2 inches to 48 inches.
10 . The flat coaxial cable of claim 1 , wherein a change in insertion loss for the flat coaxial cable, when compressed or bent between two surfaces, is less than 1 dB at a frequency of 2 megahertz, relative to an insertion loss of the flat coaxial cable when the flat coaxial cable is not compressed or bent by the two surfaces.
11 . The flat coaxial cable of claim 10 , wherein the two surfaces are a window and a window sash, wherein the flat coaxial cable is compressed when placed between the window and the window sash and the window is closed or sealed or locked.
12 . The flat coaxial cable of claim 10 , wherein the change in insertion loss for the flat coaxial cable, when compressed or bent between the two surfaces, is less than 0.2 dB at a frequency of 2 Megahertz, relative to in insertion loss at the frequency of 2 Megahertz when the flat coaxial cable is not compressed or bent between the two surfaces.
13 . A method of forming a flat coaxial cable, comprising:
adhesively joining a first ground layer and a first dielectric film to form a top section;
adhesively joining a second ground layer and a second dielectric film to form a bottom section;
providing a strip-line between the top section and the bottom section; and
adhesively joining the top section and the bottom section to surround the strip-line to form the flat coaxial cable.
14 . The method of claim 13 , further comprising electrically coupling a radio frequency connector to a first end and a second end of the first ground layer, the second ground layer, and the strip-line.
15 . The method of claim 14 , further comprising notching one of the top section and the bottom section to form an opening to enable a signal carrying conductor of the radio frequency connector to be electrically coupled to the strip-line.
16 . The method of claim 14 , further comprising connecting a ground conductor of the radio frequency connector to the first ground layer and the second ground layer.
17 . The method of claim 13 , further comprising electrically connecting a plurality of vias along a length of the cable between the first ground layer and the second ground layer.
18 . The method of claim 13 , further comprising forming the first ground layer or the second ground layer from one of a solid conductor and a mesh conductor, wherein the first ground layer and the second ground layer have a thickness of between 10 micrometers (μm) and 100 μm.
19 . The method of claim 13 , further comprising forming the first dielectric film and the second dielectric film from a Kapton film, with a thickness of between 150 μm and 900 μm.
20 . The method of claim 13 , further comprising printing the strip line on one of the first dielectric film or the second dielectric film.
21 . A flat cable, comprising:
a first ground layer;
a second ground layer;
a strip-line vertically positioned between the first ground layer and the second ground layer; and
a dielectric material vertically positioned between the first ground layer and the second ground layer and surrounding the strip-line to insulate the strip-line from the first ground layer and the second ground layer.
22 . The flat cable of claim 21 , wherein the first ground layer, the second ground layer, the strip-line, and the dielectric material are arranged in a stacked formation.
23 . The flat cable of claim 21 , wherein the flat cable is flexible such that the flat cable includes a stiffness that is within a range of stiffness that would allow a typical person to bend the flat cable with their hands without using any tools.
24 . The flat cable of claim 21 , further comprising an opening at a first end of the flexible cable through a portion of the first ground layer and the portion of the dielectric material that exposes the strip-line.
25 . The flat cable of claim 24 , further comprising a coupler, a signal carrying conductor of the coupler positioned in the opening and directly coupled to the strip-line.