Production-tolerant multi-part antenna system
This document describes high-tolerance channels for multi-part waveguide and antenna. Two structures with planar surfaces are arranged about a separation plane. The planar surfaces are contoured to shape, respectively, an upper channel section and a complementary, lower channel section from an opposite side of the separation plane. Surface features on one or both planar surfaces are shaped to provide physical dimensions (e.g., length, width, and height) for a channel between the upper and lower channel sections. When arranged about the separation plane, the two structures configure an electromagnetic (EM) energy path to propagate a desired EM energy through the channel. At least one of the surface features is shaped to compensate the physical dimensions for achieving different path dimensions inside the channel to enable the EM energy path for propagating the desired wavelength or frequency of EM energy about the separation plane.
1 . An antenna system comprising:
a first structure with a first surface;
a second structure with a second surface, the second surface extending parallel with the first surface,
wherein the first surface has planar potions and is contoured to provide an upper channel section of a channel, and
wherein the second surface has planar portions and is contoured to provide a lower channel section of the channel to complement the upper channel section;
at least one of the first and second surfaces includes a plurality of surface features, the plurality of surface features including at least one pair of ridge structures defining physical dimensions of the channel along a length of the channel, the physical dimensions include a channel width and a channel height of a cross section of the channel, the cross section extending perpendicular to i) at least one of a top surface of the first structure and a bottom surface of the second structure, and ii) the length of the channel, and the at least one pair of ridge structures extending from the at least one of the first and second surfaces such that the second structure contacts the first structure via the at least one pair of ridge structures; and
at least one of the plurality of surface features being shaped to compensate for the physical dimensions and provide an electromagnetic (EM) energy path having different path dimensions than the physical dimensions to enable a desired wavelength or frequency of EM energy to propagate through the channel.
2 . The antenna system of claim 1 , wherein the path dimensions achieve an a-dimension or b-dimension for the EM energy path that exceeds at least one of the channel width or the channel height.
3 . The antenna system of claim 2 , wherein the path dimensions of the EM energy path encompass portions of the plurality of surface features located partially within at least one pair of the plurality of surface features for the length of the channel, the pair of the plurality of surface features being separated on the first surface by the channel width and contoured to enable the EM energy path within the channel width and the channel height.
4 . The antenna system of claim 1 , wherein:
the plurality of surface features are shaped to form conductive surfaces within the physical dimensions of the channel and enforce EM boundaries along the length of the channel; and
the plurality of surface features having shapes to allow unwanted energy to leak outside the conductive surfaces of the channel.
5 . The antenna system of claim 1 , wherein:
the first surface includes at least some of the plurality of surface features and the second surface includes any remainder of the plurality of surface features; or
the first surface includes none of the plurality of surface features and the second surface includes all of the plurality of surface features.
6 . The antenna system of claim 1 , wherein the plurality of surface features produce EM boundaries for the EM energy path to have a rectangular shape along the length of the channel with an a-dimension or b-dimension that is smaller than the physical dimensions of the channel.
7 . The antenna system of claim 1 , wherein;
the at least one pair of ridge structures is shaped on the first surface to provide the physical dimensions;
the first surface comprises the plurality of surface features including pairs of ridge structures; and
the pair of ridge structures including a first pair of ridge structures providing the channel width and the channel height and a second pair of ridge structures disposed outside the first pair of ridge structures to provide a region for undesired energy to leak from the channel and be trapped between the first pair of ridge structures and the second pair of ridge structures.
8 . The antenna system of claim 1 , wherein;
the at least one pair of ridge structures is shaped on the first surface to provide the physical dimensions; and
the plurality of surface features include at least two pairs of ridge structures including the at least one pair of ridge structures, each of the pairs of ridge structures being shaped to provide the channel width and further to each provide partial walls that combine to provide the channel height.
9 . The antenna system of claim 1 , wherein:
the at least one pair of ridge structures is shaped on the first surface to provide the physical dimensions; and
the at least one pair of ridge structures vary the channel height along the length of the channel to allow undesired energy to leak from gaps between the at least one pair of ridge structures and the second surface.
10 . The antenna system of claim 1 , wherein:
the at least one pair of ridge structures is shaped on the first surface to provide the physical dimensions; and
the at least one pair of ridge structures vary the channel height on both sides of the channel to allow undesired energy to leak from gaps between the at least one pair of ridge structures and the second surface.
11 . The antenna system of claim 1 , wherein the plurality of surface features have cross sections that contour at least part of the channel height using a fillet and a non-vertical draft angle to shape surfaces inside the channel width.
12 . The antenna system of claim 1 , wherein;
the at least one pair of ridge structures is shaped on the first surface to provide the physical dimensions; and
surfaces of the at least one pair of ridge structures are shaped to have a repeating pattern in a direction along the length of the channel, the repeating pattern including a sinusoidal wave, a sawtooth wave, or a square wave.
13 . The antenna system of claim 12 , wherein;
the at least one pair of ridge structures is shaped on the first surface to provide the physical dimensions; and
the repeating pattern is along the length of the channel to compensate the physical dimensions for short-circuit effects at periodic contacts between complementary portions of the first and second surfaces by forming gaps between the periodic contacts to maintain the path dimensions.
14 . The antenna system of claim 1 , wherein each of the first and second structures comprises a metal injection molded metal part.
15 . The antenna system of claim 14 , wherein partial walls of the upper channel section or the lower channel section are metal-injection molded and have draft angles that exceed ninety degrees relative the at least one of the top surface of the first structure and the bottom surface of the second structure for enabling easier separation of the upper channel section or the lower channel section from a mold.
16 . The antenna system of claim 15 , wherein channel corners of the upper channel section or the lower channel section are filleted to extend the EM energy path from the channel corners into regions of the plurality of surface features for achieving an a-dimension or a b-dimension for the EM energy path that is located inside at least one of the channel width or the channel height.
17 . The antenna system of claim 15 , wherein an a-dimension or a b-dimension of the energy path within the partial walls is aligned to an axis that is normal to the at least one of the top surface of the first structure and the bottom surface of the second structure.
18 . The antenna system of claim 1 , wherein two structures provide an interface to the EM energy path for a signal processor or an antenna element to transmit or receive EM signals inferred from the EM energy directed on the energy path.
19 . A method for manufacturing an antenna system, the method comprising:
forming, using metal injection molding, a first metal structure for the antenna system, the first metal structure formed to have a first surface, wherein the first surface has planar portions and is contoured to provide an upper channel section of a channel;
forming, using metal injection molding, a second metal structure for the antenna system, the second metal structure formed to have a second surface that is parallel to the first surface, wherein the second surface has planar portions and is contoured to provide a lower channel section of the channel to complement the upper channel section,
wherein at least one of the first and second surfaces includes a plurality of surface features, the plurality of surface features including at least one pair of ridge structures defining physical dimensions of the channel along a length of the channel, the physical dimensions include a channel width and a channel height of a cross section of the channel, the cross section extending perpendicular to i) at least one of a top surface of the first structure and a bottom surface of the second structure, and ii) the length of the channel, and the at least one pair of ridge structures extending from the at least one of the first and second surfaces such that the second structure contacts the first metal structure via the at least one pair of ridge structures; and
arranging the first metal structure relative the second metal structure to align the first surface to be opposite the second surface and provide physical dimensions of the channel formed between the upper channel section and the lower channel section,
wherein forming at least one of the first metal structure or the second metal structure comprises shaping at least one of the plurality of surface features to compensate for the physical dimensions and provide an electromagnetic (EM) energy path having different path dimensions than the physical dimensions to enable a desired wavelength or frequency of EM energy to propagate through the channel.
20 . The antenna system of claim 1 , wherein at least one of i) the lower channel section is offset from the upper channel section such that sidewalls of the upper channel section are not horizontally in line with sidewalls of the lower channel section; and ii) the pair of ridge structures extend along the length of the channel and a cross-section of each ridge structure of the pair of ridge structures has a rounded top and extends perpendicular to the separation plane and to the length of the channel.