Patent Description:
Communications standards such as <NUM> and <NUM> are currently in wide-spread use. It is expected that infrastructure to support <NUM> communications will soon be deployed. In order to take advantage of <NUM>, 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 <NUM> to <NUM>. In order to achieve performance with such small wavelengths, multiple antennas in the shape of an array have been utilized.

<CIT> discloses a wireless communication device with leaky-wave phased array antenna. <CIT> discloses a chassis-excited antenna apparatus and methods. <CIT> discloses a beam forming auxiliary unit for antenna and terminal including the same. <CIT> discloses multi-band wireless terminals with metal backplates and multi-band antennae, and multi-band antenna systems with metal backplates and multi-band antennae. <CIT> Aldiscloses an electronic apparatus including a housing provided with a first conductive pattern, a substrate provided with a first wiring layer in a surface thereof and fixed to the housing, and a first conductive member connecting the first conductive pattern and the first wiring layer.

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 <FIG>.

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. At least one of the top edge or the bottom edge has a plurality of notches.

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 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 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 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 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.

Embodiments will now be described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout.

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 <FIG>, illustrated is an exemplary basic structure of an antenna frame <NUM> for an antenna <NUM>. Antenna frame <NUM> includes a first side portion <NUM> and a second side portion <NUM> parallel to the first side portion <NUM>. The antenna frame <NUM> also includes an end portion <NUM>. The end portion <NUM> extends along a length <NUM> from a first end <NUM> to a second end <NUM>. The end portion <NUM> includes an outer face <NUM> extending along the length <NUM> and an inner face <NUM> that also extends along the length <NUM> and is spaced apart from the outer face <NUM> by a thickness <NUM>. A top edge <NUM> extends in the thickness direction between the inner face <NUM> and the outer face <NUM>, and extends between the first end <NUM> and the second end <NUM> in the length <NUM> direction at a top of the outer face <NUM> and the inner face <NUM>. Similarly, a bottom edge <NUM> extends in the thickness direction between the inner face <NUM> and the outer face <NUM>, and extends between the first end <NUM> and the second end <NUM> in the length <NUM> direction at a bottom of the outer face <NUM> and the inner face <NUM>. The bottom edge <NUM> is spaced apart from the top edge <NUM> by a width <NUM>. In some embodiments, the antenna frame <NUM> can be constructed completely or partially of metal. Types of metal used in construction of the frame can include aluminum or stainless steel, among others. The antenna frame <NUM> can define an interior space, in which an antenna <NUM> can be located and arranged substantially behind the end portion <NUM> of the frame <NUM>. The antenna <NUM> can be further integrated within a wireless communication device and mounted on a substrate <NUM> such as a printed circuit board. The basic antenna frame <NUM> structure depicted in <FIG> can serve as the basis for the embodiments described below.

In some embodiments, the antenna frame <NUM> can be fabricated individually and integrated as part of a mobile communication device's casing. In other embodiments, antenna frame <NUM> can be a separate component that can be arranged inside of a mobile communication device. In still further embodiments, the antenna frame <NUM> can be integrated as part of the antenna <NUM> 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 <NUM> of the corresponding end portion <NUM>. 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 <NUM> of the corresponding end portion <NUM>.

Turning now to <FIG>, in this embodiment, the antenna <NUM> is vertically polarized as indicated by the vertical arrow. The antenna <NUM> is an edge-mounted antenna arranged substantially behind the end portion <NUM> of the frame <NUM>. Using prior art antenna frames, the radiation pattern produced by the antenna has a significant blind spot <NUM> as seen in the diagram <NUM> displayed in <FIG>. However, end-fire transmission from the antenna <NUM> can be improved by reducing the metal antenna frame <NUM> scattering effect. This may be accomplished by reducing the radar cross section of the metal antenna frame <NUM>, and more specifically the end portion <NUM>.

One method of reducing the radar cross section is to minimize the width <NUM> of the metal antenna frame's <NUM> end portion <NUM>. Various widths <NUM> provide differing end-fire transmission results and radiation patterns as shown in the diagram <NUM> displayed in <FIG>. Radiation pattern <NUM> results from an end portion <NUM> having a width <NUM> of <NUM> millimeters (mm). Radiation pattern <NUM> results from an end portion <NUM> having a width <NUM> of <NUM>. Radiation pattern <NUM> results from an end portion <NUM> having a width <NUM> of <NUM>. As shown in the diagram <NUM>, a smaller width <NUM> of the end portion <NUM> results in a more desirable radiation pattern, with stronger radio waves, particularly in the direction of the main lobe oriented in the direction of the end portion <NUM> of the antenna frame <NUM>. Such effect is seen when the antenna <NUM> is a vertically polarized antenna as in the embodiment displayed in <FIG>. While reducing the width of the end portion <NUM> does not have any negative effect on transmission from a horizontally polarized antenna, such reduction does not provide any substantial benefit with respect to horizontally polarized antennas.

Another method of reducing the radar cross section is to vary the thickness <NUM> of the end portion <NUM> along the width <NUM> of the end portion <NUM>. While varying the thickness <NUM> of the end portion <NUM> along the width <NUM> of the end portion <NUM> does not have any negative effect on transmission from a horizontally polarized antenna, such variation in thickness <NUM> along the width <NUM> of the end portion <NUM> does not provide any substantial benefit with respect to horizontally polarized antennas. Various embodiments of such end portions are described below with reference to <FIG>.

Turning now to <FIG>, another exemplary embodiment of an end portion for an antenna frame is shown at <NUM>. The end portion <NUM> is substantially the same as the above-referenced end portion <NUM>, and consequently the same reference numerals but indexed by <NUM> are used to denote structures corresponding to similar structures in the end portions. In addition, the foregoing description of the end portion <NUM> is equally applicable to the end portion <NUM> except as noted below and depicted in the figures.

An exemplary end portion <NUM> is shown in <FIG>. The width <NUM> of the end portion <NUM> extends from the top edge <NUM> to the bottom edge <NUM>. The thickness <NUM> of the end portion <NUM> is varied along the width <NUM> of the end portion <NUM> such that the end portion <NUM> has a triangular or wedge-shaped cross section. The outer face <NUM> remains flat, and the inner face <NUM> is angled to create the triangular or wedge-shaped cross-section. This shape reduces back radiation of the radio waves from the antenna <NUM>, thereby improving the radiation pattern as compared to an end portion <NUM> having a constant thickness <NUM> along its width <NUM>, particularly in the direction of the main lobe oriented in the direction of the end portion <NUM>. This improved radiation pattern is depicted in <FIG>, which displays a diagram <NUM> showing the radiation patterns that result from using an end portion <NUM> having a width <NUM> of <NUM> and a constant depth <NUM>, as compared to using an end portion <NUM> also having a width <NUM> of <NUM>, but having a triangular cross-section. Radiation pattern <NUM> corresponds to the use of end portion <NUM>, and radiation pattern <NUM> corresponds to the use of end portion <NUM>. Additional embodiments of the end portion <NUM> can have different cross-sectional shapes to reduce the radar cross section of the end portion <NUM>. These additional embodiments are described below with reference to <FIG>.

The width <NUM> of the end portion <NUM> extends from the top edge <NUM> to the bottom edge <NUM>. The thickness <NUM> of the end portion <NUM> is varied along the width <NUM> of the end portion <NUM> such that the end portion <NUM> has an arc-shaped cross section. The outer face <NUM> remains flat, and the inner face <NUM> has an arc-shape to create the arc-shaped cross-section. This shape reduces back radiation of the radio waves from the antenna <NUM>, thereby improving the radiation pattern as compared to an end portion <NUM> having a constant thickness <NUM> along its width <NUM>, particularly in the direction of the main lobe oriented in the direction of the end portion <NUM>.

The width <NUM> of the end portion <NUM> extends from the top edge <NUM> to the bottom edge <NUM>. The thickness <NUM> of the end portion <NUM> is varied along the width <NUM> of the end portion <NUM> such that the end portion <NUM> has a trapezoidal cross section. The outer face <NUM> remains flat, and the inner face <NUM> can have two or more angles to create the trapezoidal cross-section. This shape reduces back radiation of the radio waves from the antenna <NUM>, thereby improving the radiation pattern as compared to an end portion <NUM> having a constant thickness <NUM> along its width <NUM>, particularly in the direction of the main lobe oriented in the direction of the end portion <NUM>.

The antenna <NUM> is horizontally polarized as indicated by the horizontal arrow shown going into the page. The antenna <NUM> is an edge-mounted antenna arranged substantially behind the end portion <NUM> of the frame <NUM>. 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 <NUM> can be improved by creating a hard surface metal frame such that the electromagnetic field produced by the antenna <NUM> can propagate through the end portion <NUM> 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 <NUM>.

End portion <NUM> includes a top edge <NUM> and a bottom edge <NUM>. In order to form the corrugated or notched structure, at least one of the top edge <NUM> or the bottom edge <NUM> has a plurality of notches <NUM>. The notches <NUM> are arranged along the top edge <NUM> and/or the bottom edge <NUM> and can extend in the thickness <NUM> direction from the outer face <NUM> to the inner face <NUM> of the end portion <NUM>. The notches <NUM> can be spaced periodically along the length <NUM> of the end portion <NUM>.

Notches <NUM> can be at least partially filled with a dielectric material <NUM>. The dielectric material <NUM> can include ceramic, glass, plastic, fiberglass, or a combination thereof, among other materials. In certain embodiments, the notches <NUM> have a metal molding around the edges of the notches <NUM>. The notches <NUM> have a depth <NUM> in the width <NUM> direction of the end portion <NUM>. The depth <NUM> of the notches <NUM> is preferably at least one-quarter of the wavelength of the radio wave transmitted by the antenna <NUM> as they propagate through the dielectric material <NUM>. For higher permittivity values of the dielectric material <NUM>, the depth <NUM> of the notches <NUM> can be reduced because the wavelength of the radio wave as it is propagating through the dielectric material <NUM> is reduced. In an exemplary embodiment, the antenna <NUM> is transmitting radio waves with a frequency of <NUM> and the depth <NUM> of the notch <NUM> is <NUM> when the permittivity of the dielectric material <NUM> is <NUM>. Further, the notches <NUM> 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 <NUM>. In another embodiment, the end portion <NUM> can have a plurality of metallic strips instead of, or in addition to, the plurality of notches <NUM>.

This notched edge surface or surfaces in the end portion <NUM> creates a hard surface boundary condition that allows horizontally polarized electromagnetic waves transmitted by the antenna <NUM> to propagate through the end portion <NUM>, thereby improving the radiation pattern as compared to an end portion <NUM> having non-corrugated top and bottom edges, particularly in the direction of the main lobe oriented in the direction of the end portion <NUM>. This improved radiation pattern is depicted in <FIG>, which displays a diagram <NUM> showing the radiation patterns that result from using an end portion <NUM> having notched top and bottom edges, as compared to using various end portions <NUM> lacking a notched top and bottom edge. Radiation patterns <NUM> and <NUM> correspond to the use of end portions <NUM> having different widths <NUM>, but lacking a notched top and bottom edge, and radiation pattern <NUM> corresponds to the use of end portion <NUM>, which has notched top and bottom edges.

Turning now to <FIG>, end portion <NUM> is adapted to provide improved radiation patterns for dual-polarized antennas that may contain both vertically polarized and horizontally polarized antenna elements. In one embodiment, end portion <NUM> has a depth <NUM> that varies along the width <NUM> such that end portion <NUM> has triangular-shaped cross-section similar to that of end portion <NUM>, which reduces the radar cross section of the end portion <NUM> to improve the radiation pattern resulting from vertically polarized antenna elements. Further, a plurality of notches <NUM> are arranged along the length <NUM> of the end portion <NUM> along the top edge <NUM> and the bottom edge <NUM> to create a hard surface boundary condition to improve electromagnetic wave propagation of horizontally polarized waves to improve the radiation pattern resulting from horizontally polarized antenna elements. Notches <NUM> can extend from the outer face <NUM> to the inner face <NUM>. 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 <NUM> can also have an arc-shaped cross-section similar to end portion <NUM>, or a trapezoidal-shaped cross-section similar to end portion <NUM>.

Turning now to <FIG>, end portion <NUM> is substantially similar to end portion <NUM>, except that notches <NUM>, <NUM> of different depths are included to account for a horizontally polarized antenna that operates as a dual-band antenna. End portion <NUM> includes a top edge <NUM> and a bottom edge <NUM>. In order to form the corrugated or notched structure, at least one of the top edge <NUM> or the bottom edge <NUM> has a plurality of notches <NUM>, <NUM> having different depths <NUM>, <NUM>. First notches <NUM> having a first depth <NUM> can be alternated with second notches <NUM> having a second depth <NUM>. The first depth <NUM> of the first notches <NUM> is preferably at least one-quarter of the wavelength of the radio wave transmitted by the antenna <NUM> on a first band as the radio wave propagates through the dielectric material <NUM>. Similarly, the second depth <NUM> of the second notches <NUM> is preferably at least one-quarter of the wavelength of the radio wave transmitted by the antenna <NUM> on a second band as the radio wave propagates through the dielectric material <NUM>. In this manner, first notches <NUM> provide a transmission benefit for radio waves having a first wavelength on the first band, and second notches <NUM> provide a transmission benefit for radio waves having a second wavelength on the second band. The notches <NUM>, <NUM> are arranged along the top edge <NUM> and/or the bottom edge <NUM> and can extend in the thickness <NUM> direction from the outer face <NUM> to the inner face <NUM> of the end portion <NUM>. The notches <NUM>, <NUM> can be spaced periodically along the length <NUM> of the end portion <NUM>.

Notches <NUM>, <NUM> can be at least partially filled with a dielectric material <NUM>. The dielectric material <NUM> can include ceramic, glass, plastic, fiberglass, or a combination thereof, among other materials. It should be appreciated that first notches <NUM> and second notches <NUM> can be filled with the same dielectric material <NUM> or different dielectric material <NUM>, and the depths <NUM>, <NUM> of the notches <NUM>, <NUM> can be selected based on the dielectric material used <NUM>. In certain embodiments, the notches <NUM>, <NUM> have a metal molding around the edges of the notches <NUM>, <NUM>.

Turning now to <FIG>, end portion <NUM> is adapted to provide improved radiation patterns for dual-polarized/dual-band antennas that contain both vertically polarized and horizontally polarized antenna elements and also communicate on two bands. In one embodiment, end portion <NUM> has a depth <NUM> that varies along the width <NUM> such that end portion <NUM> has a triangular-shaped cross-section similar to that of end portion <NUM>, which reduces the radar cross section of the end portion <NUM> to improve the radiation pattern resulting from vertically polarized antenna elements. Further, a plurality of notches <NUM>, <NUM> having different depths <NUM>, <NUM> are arranged along the length <NUM> of the end portion <NUM> along the top edge <NUM> and the bottom edge <NUM> to create a hard surface boundary condition to improve electromagnetic wave propagation of horizontally polarized waves to improve the radiation pattern resulting from horizontally polarized antenna elements.

First notches <NUM> having a first depth <NUM> can be alternated with second notches <NUM> having a second depth <NUM>. The first depth <NUM> of the first notches <NUM> is preferably at least one-quarter of the wavelength of the horizontally polarized radio wave transmitted by the antenna <NUM> on a first band as the radio wave propagates through the dielectric material <NUM>. Similarly, the second depth <NUM> of the second notches <NUM> is preferably at least one-quarter of the wavelength of the radio wave transmitted by the antenna <NUM> on a second band as the radio wave propagates through the dielectric material <NUM>. In this manner, first notches <NUM> provide a transmission benefit for radio waves having a first wavelength on the first band, and second notches <NUM> provide a transmission benefit for radio waves having a second wavelength on the second band. Notches <NUM> can extend from the outer face <NUM> to the inner face <NUM>. 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 <NUM> can also have an arc-shaped cross-section similar to end portion <NUM>, or a trapezoidal-shaped cross-section similar to end portion <NUM>.

Claim 1:
An antenna frame (<NUM>) for a wireless communication device, comprising:
an end portion (<NUM>, <NUM>, <NUM>) comprising:
a first end;
a second end spaced apart from the first end to define a length;
an outer face (<NUM>, <NUM>, <NUM>) that extends along the length;
an inner face (<NUM>, <NUM>, <NUM>) that extends along the length and is spaced apart from the outer face (<NUM>, <NUM>, <NUM>) by a thickness (<NUM>, <NUM>, <NUM>);
a top edge (<NUM>, <NUM>, <NUM>) extending between the inner face (<NUM>, <NUM>, <NUM>) and the outer face (<NUM>, <NUM>, <NUM>) in the thickness (<NUM>, <NUM>, <NUM>) direction and between the first end and the second end in the length direction at a top of the outer (<NUM>, <NUM>, <NUM>) and inner faces (<NUM>, <NUM>, <NUM>); and
a bottom edge (<NUM>, <NUM>, <NUM>) extending between the inner face (<NUM>, <NUM>, <NUM>) and the outer face (<NUM>, <NUM>, <NUM>) in the thickness (<NUM>, <NUM>, <NUM>) direction and between the first end and the second end in the length direction at a bottom of the outer (<NUM>, <NUM>, <NUM>) and inner faces (<NUM>, <NUM>, <NUM>), wherein
the bottom edge (<NUM>, <NUM>, <NUM>) is spaced apart from the top edge (<NUM>, <NUM>, <NUM>) by a width (<NUM>, <NUM>, <NUM>), and the thickness (<NUM>, <NUM>, <NUM>) of the end portion (<NUM>, <NUM>, <NUM>) varies along the width (<NUM>, <NUM>, <NUM>) of the end portion (<NUM>, <NUM>, <NUM>),
characterized in that:
at least one of the top edge (<NUM>, <NUM>, <NUM>) or the bottom edge (<NUM>, <NUM>, <NUM>) has a plurality of notches (<NUM>, <NUM>, <NUM>, <NUM>).