Abstract: This document describes techniques, apparatuses, and systems for a wave-shaped ground structure for antenna arrays. A radar system may include a ground structure with a first surface having a wave shape and a second surface opposite the first surface. The ground structure includes multiple antenna arrays separated in a longitudinal direction on the first surface. Each antenna array includes one or more antenna elements configured to emit or receive electromagnetic (EM) energy. The ground structure also includes antenna feeds separated in the longitudinal direction on the second surface and operably connected to the antenna arrays. The wave shape of the ground structure configures the radar system to provide an antenna radiation pattern that provides a uniform radiation pattern among the antenna arrays. The wave shape can also be configured to provide an asymmetrical radiation pattern or a narrow beamwidth for specific applications.

Abstract: An electromagnetic band-gap (EBG) structure includes an antenna substrate layer, first conductive regions, and second conductive regions. The antenna substrate includes a first planar surface and a second planar surface. The first conductive regions are located on the first planar surface of the antenna substrate and separated from adjacent first conductive regions by a first distance. The second conductive regions are located on the first planar surface of the antenna substrate and are separated from the first conductive regions by a second distance and wherein the second conductive regions at least partially surround the first conductive regions.

Abstract: This document describes techniques and systems for planar surface features for waveguides and antennas. Two structures are arranged with opposing planar surfaces fixed adjacent to a separation plane dividing a channel (e.g., a waveguide, a feed network) to provide an energy path for propagating electromagnetic energy. Part of the channel is formed between side walls of a recessed groove within one opposing surface; another channel part is formed by an arrangement of surface features spaced and shaped on the other opposing surface. At least two surface features are adjacent protrusions contoured to compliment the sidewalls of the recessed groove. An area on each opposing surface between the recessed groove and the adjacent protrusions is configured to form the energy path through the channel including to prevent energy leakage from the separation plane dividing the channel.

Abstract: This document describes techniques and systems for planar surface features for achieving antenna coverage. A structure is configured to provide a feed network for propagating electromagnetic energy along an energy path formed under a planar surface. The planar surface includes a recessed cavity with walls surrounding a cavity floor embedded within the planar surface. The cavity floor is shaped to form radiating slot(s) open through the structure to the energy path under the planar surface. A ridge feature protrudes from the planar surface on either side of the recessed cavity with a ridge length that is parallel with the cavity walls and a ridge height set to prevent cross-interference near the radiating slot within the cavity floor, thereby narrowing coverage for the electromagnetic energy within the feed network.

Abstract: A waveguide includes a printed circuit board (PCB) having a first conductive layer, a second substrate layer, and a third conductive layer. The waveguide includes a hollow channel for a dielectric that includes a first opening in a longitudinal direction through the hollow channel at one end of the waveguide and a closed wall at an opposite end of the waveguide, the third conductive layer forming a surface of the hollow channel that defines the hollow channel and a plurality of radiation slots, each of the plurality of radiation slots comprising a second opening formed in the second substrate layer, each of the plurality of radiation slots being operably connected with the dielectric.

Abstract: The present disclosure generally relates to monitoring and controlling emissions produced by a fuel cell or fuel cell stack in a fuel cell engine of a vehicle and/or powertrain.

Abstract: This document describes a waveguide with a zigzag for suppressing grating lobes. An apparatus may include a waveguide with a zigzag waveguide channel to suppress grating lobes in diagonal planes of a three-dimensional radiation pattern. The waveguide includes a hollow channel containing a dielectric and an array of radiation slots through a surface that is operably connected with the dielectric. The hollow channel has a zigzag shape along a longitudinal direction through the waveguide. The zigzag waveguide channel and radiation slots configure the described waveguide to suppress grating lobes in an antenna radiation pattern. This document also describes a waveguide formed in part by a printed circuit board to improve the manufacturing process.

Abstract: This document describes a waveguide with radiation slots and parasitic elements for asymmetrical coverage. An apparatus may include a waveguide for providing asymmetrical coverage in an azimuth plane. The waveguide includes a hollow channel containing a dielectric and an array of radiation slots through a surface that is operably connected with the dielectric. The waveguide includes an array of parasitic elements positioned on or in the surface and offset from a longitudinal side of the array of radiation slots. The radiation slots and parasitic elements configure the described waveguide to focus an antenna radiation pattern that provides an asymmetrical coverage to focus on a particular portion within the antenna field-of-view.

Abstract: This document describes a waveguide with radiation slots and parasitic elements for asymmetrical coverage. An apparatus may include a waveguide for providing asymmetrical coverage in an azimuth plane. The waveguide includes a hollow channel containing a dielectric and an array of radiation slots through a surface that is operably connected with the dielectric. The waveguide includes an array of parasitic elements positioned on or in the surface and offset from a longitudinal side of the array of radiation slots. The radiation slots and parasitic elements configure the described waveguide to focus an antenna radiation pattern that provides an asymmetrical coverage to focus on a particular portion within the antenna field-of-view.

Abstract: A radiation pattern reconfigurable antenna includes an input port, a signal divider, a filter, and first and second radiators. The signal divider is connected to the input port and configured to divide a signal at the input port into a first output and a second output. The filter is connected to the second output, wherein the filter is configured to filter signal within a first frequency band and to pass signals within a second frequency band. The first radiator is configured to receive the signal from the first output of the signal divider, wherein the first radiator receives signals within the first frequency band and the second frequency band. The second radiator is connected to the filter to receive signals provided within the second frequency band.

Abstract: This document describes techniques, apparatuses, and systems directed to a waveguide end array antenna to reduce grating lobes and cross-polarization. Referred to simply as the waveguide, for short, utilizes a core made of a dielectric material to guide electromagnetic energy from a waveguide input to one or more radiating slots. The dielectric core includes a main channel and one or more forks. Each fork connects the main channel to one or more tine sections, and each tine section is terminated by a closed end and a radiating slot. These radiating slots are separated from each other by a distance to enable at least a portion of the electromagnetic energy to dissipate in phase through the radiating slots. The dielectric core of the waveguide reduces grating lobes and cross-polarization associated with the electromagnetic energy. An automobile can rely on the waveguide to detect objects with increased accuracy.

Abstract: This document describes techniques, apparatuses, and systems for a wave-shaped ground structure for antenna arrays. A radar system may include a ground structure with a first surface having a wave shape and a second surface opposite the first surface. The ground structure includes multiple antenna arrays separated in a longitudinal direction on the first surface. Each antenna array includes one or more antenna elements configured to emit or receive electromagnetic (EM) energy. The ground structure also includes antenna feeds separated in the longitudinal direction on the second surface and operably connected to the antenna arrays. The wave shape of the ground structure configures the radar system to provide an antenna radiation pattern that provides a uniform radiation pattern among the antenna arrays. The wave shape can also be configured to provide an asymmetrical radiation pattern or a narrow beamwidth for specific applications.

Abstract: A radiation pattern reconfigurable antenna includes an input port, a signal divider, a filter, and first and second radiators. The signal divider is connected to the input port and configured to divide a signal at the input port into a first output and a second output. The filter is connected to the second output, wherein the filter is configured to filter signal within a first frequency band and to pass signals within a second frequency band. The first radiator is configured to receive the signal from the first output of the signal divider, wherein the first radiator receives signals within the first frequency band and the second frequency band. The second radiator is connected to the filter to receive signals provided within the second frequency band.

Abstract: This document describes a twin line fed dipole array antenna that may be coupled to several different types of feed networks in a space-efficient manner. The antenna makes use of a twin line feed to a plurality of dipoles that minimizes cross-polarization. The antenna may be manufactured on a printed circuit board (PCB) and has a centered feed slot that is easily coupled to several different types of waveguides or a microstrip. In some implementations, the dipole elements may have an approximately rectangular shape. In other implementations, the dipole elements may have an approximately bowtie shape, round shape, oval shape, C-shape, or L-shape. The size and placement of the dipole elements may be optimized for certain operating frequencies of the radar system to which the antenna is coupled.

Abstract: The present disclosure generally relates to monitoring and controlling emissions produced by a fuel cell or fuel cell stack in a fuel cell engine of a vehicle and/or powertrain.

Abstract: A radiation pattern reconfigurable antenna includes an input port, a signal divider, a filter, and first and second radiators. The signal divider is connected to the input port and configured to divide a signal at the input port into a first output and a second output. The filter is connected to the second output, wherein the filter is configured to filter signal within a first frequency band and to pass signals within a second frequency band. The first radiator is configured to receive the signal from the first output of the signal divider, wherein the first radiator receives signals within the first frequency band and the second frequency band. The second radiator is connected to the filter to receive signals provided within the second frequency band.

Abstract: An illustrative example antenna device includes a substrate. A plurality of conductive members in the substrate establish a substrate integrated waveguide. A plurality of first and second slots are on an exterior surface of a first portion of the substrate. Each of the second slots is associated with a respective one of the first slots. The first and second slots are configured to establish a radiation pattern that varies across a beam of radiation emitted by the antenna device. A plurality of parasitic interruptions include slots on the exterior surface of a second portion of the substrate. The parasitic interruptions reduce ripple effects otherwise introduced by adjacent antennas.

Abstract: This document describes a waveguide with slot-fed dipole elements. An apparatus may include a waveguide for providing narrow coverage in an azimuth plane. The waveguide includes a hollow channel containing a dielectric and an array of radiation slots through a surface that is operably connected with the dielectric. The waveguide includes an array of dipole elements positioned on or in the surface and offset from each longitudinal side of the array of radiation slots. The radiation slots and the dipole elements configure the described waveguide to focus an antenna radiation pattern that supports a narrow beamwidth.

Abstract: This document describes a waveguide with radiation slots and parasitic elements for asymmetrical coverage. An apparatus may include a waveguide for providing asymmetrical coverage in an azimuth plane. The waveguide includes a hollow channel containing a dielectric and an array of radiation slots through a surface that is operably connected with the dielectric. The waveguide includes an array of parasitic elements positioned on or in the surface and offset from a longitudinal side of the array of radiation slots. The radiation slots and parasitic elements configure the described waveguide to focus an antenna radiation pattern that provides an asymmetrical coverage to focus on a particular portion within the antenna field-of-view.

Abstract: This document describes a twin line fed dipole array antenna that may be coupled to several different types of feed networks in a space-efficient manner. The antenna makes use of a twin line feed to a plurality of dipoles that minimizes cross-polarization. The antenna may be manufactured on a printed circuit board (PCB) and has a centered feed slot that is easily coupled to several different types of waveguides or a microstrip. In some implementations, the dipole elements may have an approximately rectangular shape. In other implementations, the dipole elements may have an approximately bowtie shape, round shape, oval shape, C-shape, or L-shape. The size and placement of the dipole elements may be optimized for certain operating frequencies of the radar system to which the antenna is coupled.