The technology of the present disclosure relates generally to antenna frames for mobile communication devices and, more particularly, to an antenna frame that supports transmission of millimeter wave frequencies.
Communications standards such as 3G and 4G are currently in wide-spread use. It is expected that infrastructure to support 5G communications will soon be deployed. In order to take advantage of 5G, portable electronic devices such as mobile telephones will need to be configured with the appropriate communications components and corresponding structures. These components include an antenna that has one or more resonant frequencies in the millimeter (mm) wave range, which extends from 10 GHz to 100 GHz. In order to achieve performance with such small wavelengths, multiple antennas in the shape of an array have been utilized.
At mmWave frequencies, conventional antennas may induce a strong surface wave in the chassis (housing) of the mobile device that distorts the radiation pattern emitted by the antenna element. This distortion can lead to poor operational performance and may prevent antenna array applications. This phenomenon occurs since the electrical size of the chassis in terms of wavelength is much larger than the wavelength of the emitted signal. Similarly, a metal frame located in front of the antenna array can result in distortion of the antenna pattern and cause a significant blind area in the end-fire direction as seen in
This disclosure describes an antenna frame for a wireless communication device. The antenna frame includes an end portion having a thickness that varies along the width of the end portion, with the goal of reducing the radar cross section of the end portion. This disclosure also describes an antenna frame having an end portion with a plurality of notches in the top edge and/or the bottom edge. These notches may be at least partially filled with a dielectric material.
According to aspects of the disclosure, an antenna frame for a wireless communication device includes an end portion. The end portion includes a first end, a second end spaced apart from the first end to define a length, an outer face that extends along the length, an inner face that extends along the length and is spaced apart from the outer face by a thickness, a top edge extending between the inner face and the outer face in the thickness direction and between the first end and the second end in the length direction at a top of the outer and inner faces, and a bottom edge extending between the inner face and the outer face in the thickness direction and between the first end and the second end in the length direction at a bottom of the outer and inner faces. The bottom edge is spaced apart from the top edge by a width, and the thickness of the end portion varies along the width of the end portion.
According to one embodiment of the antenna frame, the thickness of the end portion at the top edge and the bottom edge is less than the thickness of the end portion at any point in between the top edge and the bottom edge.
According to one embodiment of the antenna frame, the thickness varies along the width of the end portion such that the inner face has an arc shape.
According to one embodiment of the antenna frame, the thickness varies along the width of the end portion such that the end portion has a triangular cross section.
According to one embodiment of the antenna frame, the thickness varies along the width of the end portion such that the end portion has a trapezoidal cross section.
According to one embodiment of the antenna frame, the frame is at least partially constructed of a metal.
According to aspects of the disclosure, a wireless communication device includes the antenna frame. The antenna frame defines an interior space and the wireless communication device further comprises an antenna located within the interior space. The antenna comprises one or more antenna elements that are arranged substantially behind the end portion of the antenna frame.
According to one embodiment of the wireless communication device, the antenna is a vertically polarized antenna with a main lobe of radiation pattern facing outward through the end portion.
According to aspects of the disclosure, an antenna frame for a wireless communication device includes a first end, a second end spaced apart from the first end to define a length, an outer face that extends along the length, an inner face that extends along the length and is spaced apart from the outer face by a thickness, a top edge extending between the inner face and the outer face in the thickness direction and between the first end and the second end in the length direction at a top of the outer and inner faces, and a bottom edge extending between the inner face and the outer face in the thickness direction and between the first end and the second end in the length direction at a bottom of the outer and inner faces. At least one of the top edge or the bottom edge has a plurality of notches.
According to one embodiment of the antenna frame, both the top edge and the bottom edge have a plurality of notches.
According to one embodiment of the antenna frame, the plurality of notches are spaced periodically along the length of the end portion.
According to one embodiment of the antenna frame, one or more of the plurality of notches are at least partially filled with a dielectric material.
According to one embodiment of the antenna frame, the dielectric material is ceramic, glass, plastic, fiberglass, or a combination thereof.
According to one embodiment of the antenna frame, the wireless communication device is configured to transmit and receive communications using radio waves having a wavelength while passing through the dielectric material, and the plurality of notches have a depth measuring at least one-quarter of the wavelength.
According to one embodiment of the antenna frame, the plurality of notches have a metal molding.
According to one embodiment of the antenna frame, the frame is at least partially constructed of metal.
According to one embodiment of the antenna frame, the bottom edge is spaced apart from the top edge by a width, and the thickness of the end portion varies along the width of the end portion.
According to one embodiment of the antenna frame, the thickness of the end portion at the top edge and the bottom edge is less than the thickness of the end portion at any point in between the top edge and the bottom edge.
According to one embodiment of the antenna frame, the thickness varies along the width of the end portion such that the inner face has an arc shape.
According to one embodiment of the antenna frame, the thickness varies along the width of the end portion such that the end portion has a triangular cross section.
According to one embodiment of the antenna frame, the thickness varies along the width of the end portion such that the end portion has a trapezoidal cross section.
According to one embodiment of the antenna frame, the plurality of notches comprises a first notch having a first depth and a second notch having a second depth.
According to one embodiment of the antenna frame, the wireless communication device is configured to transmit and receive communications using radio waves having a first wavelength while passing through the dielectric material and radio waves having a second wavelength while passing through the dielectric material, and the first depth measuring at least one-quarter of the first wavelength and the second depth measuring at least one-quarter of the second wavelength.
According to aspects of the disclosure, a wireless communication device includes the antenna frame. The antenna frame defines an interior space and the electronic device further includes an antenna located within the interior space. The antenna includes one or more antenna elements that are arranged substantially behind the end portion of the antenna frame.
According to one embodiment of the wireless communication device, the antenna is a horizontally polarized antenna with a main lobe of radiation pattern facing outward through the end portion.
According to aspects of the disclosure, a wireless communication device includes the antenna frame. The antenna frame defines an interior space and the electronic device further includes an antenna located within the interior space. The antenna includes one or more antenna elements that are arranged substantially behind the end portion of the antenna frame.
According to one embodiment of the wireless communication device, the antenna is a dual-polarized antenna with a main lobe of radiation pattern facing outward through the end portion.
According to one embodiment of the wireless communication device, the antenna is a dual-band antenna with a main lobe of radiation pattern facing outward through the end portion.
According to aspects of the disclosure, an antenna includes the antenna frame and one or more antenna elements.
Embodiments will now be described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. It will be understood that the figures are not necessarily to scale. Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments and/or in combination with or instead of the features of the other embodiments.
Described below, in conjunction with the appended figures, are various embodiments of antenna frame structures that may be used with mobile terminals, such as mobile telephones. Although some figures illustrate one antenna, it will be understood that the mobile terminal may include an array of the antennas for a beam shaping or sweeping application.
Referring to
In some embodiments, the antenna frame 14 can be fabricated individually and integrated as part of a mobile communication device's casing. In other embodiments, antenna frame 14 can be a separate component that can be arranged inside of a mobile communication device. In still further embodiments, the antenna frame 14 can be integrated as part of the antenna 16 to form an antenna unit.
For the purposes of this disclosure, the term vertical polarization refers to radio waves that are polarized in the vertical direction, where the vertical direction is in the same direction as the width 40 of the corresponding end portion 22. The term horizontal polarization refers to radio waves that are polarized in the horizontal direction, where the horizontal direction is in the same direction as the length 24 of the corresponding end portion 22.
Turning now to
One method of reducing the radar cross section is to minimize the width 40 of the metal antenna frame's 14 end portion 22. Various widths 40 provide differing end-fire transmission results and radiation patterns as shown in the diagram 44 displayed in
Another method of reducing the radar cross section is to vary the thickness 34 of the end portion 22 along the width 40 of the end portion 22. While varying the thickness 34 of the end portion 22 along the width 40 of the end portion 22 does not have any negative effect on transmission from a horizontally polarized antenna, such variation in thickness 34 along the width 40 of the end portion 22 does not provide any substantial benefit with respect to horizontally polarized antennas. Various embodiments of such end portions are described below with reference to
Turning now to
An exemplary end portion 122 is shown in
Turning now to
The width 240 of the end portion 222 extends from the top edge 236 to the bottom edge 238. The thickness 234 of the end portion 222 is varied along the width 240 of the end portion 222 such that the end portion 222 has an arc-shaped cross section. The outer face 230 remains flat, and the inner face 232 has an arc-shape to create the arc-shaped cross-section. This shape reduces back radiation of the radio waves from the antenna 16, thereby improving the radiation pattern as compared to an end portion 22 having a constant thickness 34 along its width 40, particularly in the direction of the main lobe oriented in the direction of the end portion 222.
Turning now to
The width 340 of the end portion 322 extends from the top edge 336 to the bottom edge 338. The thickness 334 of the end portion 322 is varied along the width 340 of the end portion 322 such that the end portion 322 has a trapezoidal cross section. The outer face 330 remains flat, and the inner face 332 can have two or more angles to create the trapezoidal cross-section. This shape reduces back radiation of the radio waves from the antenna 16, thereby improving the radiation pattern as compared to an end portion 22 having a constant thickness 34 along its width 40, particularly in the direction of the main lobe oriented in the direction of the end portion 322.
Turning now to
The antenna 58 is horizontally polarized as indicated by the horizontal arrow shown going into the page. The antenna 58 is an edge-mounted antenna arranged substantially behind the end portion 422 of the frame 14. Using prior art antenna frames, strong reflection can be observed on the edges of the prior art end portion. However, end-fire transmission from the antenna 58 can be improved by creating a hard surface metal frame such that the electromagnetic field produced by the antenna 58 can propagate through the end portion 422 rather than being diffracted. This may be accomplished by forming corrugated or a notched top and/or bottom edge structures as part of the end portion 422.
End portion 422 includes a top edge 436 and a bottom edge 438. In order to form the corrugated or notched structure, at least one of the top edge 436 or the bottom edge 438 has a plurality of notches 460. The notches 460 are arranged along the top edge 436 and/or the bottom edge 438 and can extend in the thickness 434 direction from the outer face 430 to the inner face 432 of the end portion 422. The notches 460 can be spaced periodically along the length 424 of the end portion 422.
Notches 460 can be at least partially filled with a dielectric material 464. The dielectric material 464 can include ceramic, glass, plastic, fiberglass, or a combination thereof, among other materials. In certain embodiments, the notches 460 have a metal molding around the edges of the notches 460. The notches 460 have a depth 462 in the width 440 direction of the end portion 422. The depth 462 of the notches 460 is preferably at least one-quarter of the wavelength of the radio wave transmitted by the antenna 58 as they propagate through the dielectric material 464. For higher permittivity values of the dielectric material 464, the depth 462 of the notches 460 can be reduced because the wavelength of the radio wave as it is propagating through the dielectric material 464 is reduced. In an exemplary embodiment, the antenna 58 is transmitting radio waves with a frequency of 28 GHz and the depth 462 of the notch 460 is 1 mm when the permittivity of the dielectric material 464 is 10. Further, the notches 460 should preferably be spaced apart from each other by a distance that is less than one-quarter of the wavelength of the radio wave while propagating through the dielectric material 464. In another embodiment, the end portion 422 can have a plurality of metallic strips instead of, or in addition to, the plurality of notches 460.
This notched edge surface or surfaces in the end portion 422 creates a hard surface boundary condition that allows horizontally polarized electromagnetic waves transmitted by the antenna 58 to propagate through the end portion 422, thereby improving the radiation pattern as compared to an end portion 22 having non-corrugated top and bottom edges, particularly in the direction of the main lobe oriented in the direction of the end portion 422. This improved radiation pattern is depicted in
Turning now to
Turning now to
Notches 660, 666 can be at least partially filled with a dielectric material 664. The dielectric material 664 can include ceramic, glass, plastic, fiberglass, or a combination thereof, among other materials. It should be appreciated that first notches 660 and second notches 666 can be filled with the same dielectric material 664 or different dielectric material 664, and the depths 662, 668 of the notches 660, 666 can be selected based on the dielectric material used 664. In certain embodiments, the notches 660, 666 have a metal molding around the edges of the notches 660, 666.
Turning now to
First notches 760 having a first depth 762 can be alternated with second notches 766 having a second depth 768. The first depth 762 of the first notches 760 is preferably at least one-quarter of the wavelength of the horizontally polarized radio wave transmitted by the antenna 58 on a first band as the radio wave propagates through the dielectric material 764. Similarly, the second depth 768 of the second notches 766 is preferably at least one-quarter of the wavelength of the radio wave transmitted by the antenna 58 on a second band as the radio wave propagates through the dielectric material 664. In this manner, first notches 760 provide a transmission benefit for radio waves having a first wavelength on the first band, and second notches 766 provide a transmission benefit for radio waves having a second wavelength on the second band. Notches 760 can extend from the outer face 730 to the inner face 732. It should be appreciated that an end portion designed for dual polarized antennas can employ any shape cross-section described in regards to aforementioned embodiments. For example, end portion 722 can also have an arc-shaped cross-section similar to end portion 222, or a trapezoidal-shaped cross-section similar to end portion 322.
Notches 760, 766 can be at least partially filled with a dielectric material 764. The dielectric material 764 can include ceramic, glass, plastic, fiberglass, or a combination thereof, among other materials. It should be appreciated that first notches 760 and second notches 766 can be filled with the same dielectric material 764 or different dielectric material 764, and the depths 762, 768 of the notches 760, 766 can be selected based on the dielectric material used 764. In certain embodiments, the notches 760, 766 have a metal molding around the edges of the notches 760, 766.
Although certain embodiments have been shown and described, it is understood that equivalents and modifications falling within the scope of the appended claims will occur to others who are skilled in the art upon the reading and understanding of this specification.
Filing Document | Filing Date | Country | Kind |
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PCT/US2018/044579 | 7/31/2018 | WO | 00 |