Patent Description:
Further, optional, features are provided in the dependent claims.

The described technology addresses such limitations by providing a computing device including a metal frame forming an exterior surface of the computing device and including an array of resonant cavities. Each resonant cavity has a center axis and defining a volume within the metal frame. Each volume contains a corresponding metal plate positioned within the volume on the center axis of the resonant cavity and a corresponding metal feed line positioned to capacitively drive the corresponding metal plate and the resonant cavity. At least a portion of the corresponding metal feed line is positioned within the volume on the center axis of the resonant cavity.

The described technology provides a hybrid antenna assembly that is capable of providing acceptable antenna performance over a wide frequency bandwidth between <NUM> and <NUM> for <NUM> mmWave deployments. In one implementation, the described hybrid antenna assembly provides a return loss no more than -<NUM> dB from <NUM> to over <NUM> and a return loss of equal to or less than -<NUM> dB in frequencies bands centered near <NUM> and <NUM>, although other performance objectives may be achieved. The center frequencies can be adjusted to higher or lower frequencies by adjusting component dimensions and geometries and/or the matching characteristics of a metal feed line. Accordingly, the low return loss of the hybrid antenna assembly across the wide range of <NUM> to <NUM> allows a computing device to be selectively configured via software (or a hardware switch) to operate at multiple frequency bands having center frequencies across this wide frequency range without requiring a modification to the physical structure of the hybrid antenna assembly. However, designing a <NUM> antenna that operates acceptably across such a wide bandwidth is problematic using existing antenna implementations, such as typical patch antennas, because they provide operational bandwidths that are too narrow to support such a wide range of frequencies.

<FIG> illustrates an example computing device <NUM> with an array <NUM> of antenna assemblies (such as antenna assembly <NUM>) positioned on a metal frame <NUM> of a metal computing device case. In the illustrated implementation, the resonant cavity of each antenna assembly forms an oblong aperture in a surface of the metal frame as an opening to the resonant cavity. The aperture can be substantially square or circular in its basic shape, and the term "oblong" means deviating from a square or circular form by elongation in one dimension. In other variations, the aperture may be in the form of other shapes, including without limitation circles and other curved shapes, squares, hexagons, octagons and other multi-sided polygons, and combinations of curved and straight sided shapes. The resonant cavity of each antenna assembly also defines a volume within the metal frame <NUM>. In one implementation, the volume of the resonant cavity contains a metal plate and at least a portion of a metal feed line (e.g., a metal trace or other conductor). The volume of the resonant cavity may also contain a non-gaseous dielectric material "filler," which maintains separation among the metal feed line, the metal plate, and the interior surface of the resonant cavity.

Each antenna assembly is electrically connectable to a radio frequency signal source <NUM> by a radio frequency switch <NUM>. The radio frequency signal source <NUM> can be set to source a radio frequency signal through the radio frequency switch <NUM> to one or more of the metal feed lines of the antenna assemblies. The radio frequency signal is an electrical signal that can be centered about one of multiple center frequencies within the wide frequency bandwidth supported by the antenna assemblies. For example, one mobile communications carrier may be licensed to use a frequency band centered at about <NUM>, and another may be licensed to use a frequency band center at about <NUM>. The radio frequency signal source can be set (e.g., by a software setting) to supply a signal centered at either frequency, and the antenna assemblies can provide excellent return loss performance at either center frequency.

In one implementation, the different center frequencies available for the radio frequency signal can resonate different sets of antenna components, thereby selecting the frequency band of radio frequency waves generated by each antenna assembly. For example, based on the antenna component dimensions and geometries and/or the matching characteristics of a metal feed line, if the radio frequency signal is set near a first center frequency, the metal feed line can capacitively drive the resonant cavity to resonate predominately within a first frequency band. Alternatively, if the radio frequency signal is set near a second center frequency, the metal feed line can capacitively drive the metal plate to resonate so that the metal plate capacitively drives the resonant cavity to resonate predominately within a second frequency band.

An antenna assembly capable of such performance across a wide range of frequencies can support multiple carriers in multiple jurisdictions without physically modifying the antenna assembly design. Example <NUM> frequency bands used in various jurisdictions are listed in the table below:.

The radio frequency switch <NUM> can also selectively supply the radio frequency signal to any of the antenna assemblies and can scan from one antenna assembly to another, as illustrated by the dashed arrows <NUM> and <NUM> and the scanned radio frequency waves <NUM>, to provide multi-beam active antenna operation. Such beam scanning and steering techniques can provide acceptable gain for millimeter wave frequencies while allowing smaller antennas.

Each antenna assembly includes a resonant cavity cut or otherwise formed in the metal frame <NUM> of the computing device case. In the illustrated implementation, the metal frame <NUM> is positioned as an exterior surface at an edge of the computing device <NUM>, although other implementations may position the metal frame <NUM> at other surfaces of the computing device <NUM>.

<FIG> illustrates a perspective view of an example antenna assembly <NUM>. A portion of a metal frame <NUM> is shown with single antenna assembly <NUM>. The antenna assembly <NUM> includes a resonant cavity <NUM> formed between two exterior surfaces of the metal frame <NUM>. The resonant cavity <NUM> defines a substantially cylindrical volume having an oblong cross-section (e.g., <NUM> x <NUM>, <NUM> x <NUM>) and having a center axis extended substantially orthogonally between the two surfaces. It should be understood that other three-dimensional shapes of resonant cavities may be employed, including substantially box-like cavities with square apertures. "Orthogonal" is defined to mean <NUM>°, give or take reasonable manufacturing tolerances. "Substantially orthogonally" is defined to mean less than <NUM>° from orthogonal. Likewise, implementations may include sloped cavities in which the center axis is at an angle other than <NUM>° with reference to one or more surfaces of the metal frame <NUM>. For example, in some implementations, the center axis may be off-orthogonal by less than <NUM>°, less than <NUM>°, less than <NUM>°, and by more than <NUM>° at one or more of the surfaces of the metal frame <NUM>.

The volume of the resonant cavity <NUM> contains a metal plate <NUM> that is separated from the metal frame <NUM> and the interior surface of the resonant cavity <NUM> by a non-gaseous dielectric material. In one implementation, the metal plate <NUM> is substantially circular or oblong and is centered at and oriented orthogonal to a center axis of the resonant cavity <NUM> extending between opposing surfaces of the metal frame <NUM>. In other implementations, the metal plate <NUM> may be positioned off-center with respect to the center axis of the resonant cavity <NUM> (in one or more dimensions) and may be off-orthogonal by less than <NUM>°, less than <NUM>°, less than <NUM>°, and by more than <NUM>° with respect to the center axis of the resonant cavity <NUM>.

The volume of the resonant cavity <NUM> also contains at least a portion of a metal feed line <NUM> that can be electrically connected to a radio frequency signal source (not shown in <FIG>), which provides a radio frequency signal to the metal feed line <NUM>. In various implementations, the resonant cavity <NUM> is at least partially filled with the non-gaseous dielectric material that supports the metal plate and metal feed line <NUM> within the resonant cavity <NUM> and maintains separation among the metal feed line <NUM>, the metal plate <NUM>, and the interior surface <NUM> of the resonant cavity <NUM>. In one implementation, the metal plate <NUM> is positioned within the resonant cavity <NUM> between an exterior surface of the metal frame <NUM> and the metal feed line <NUM>, although in alternative implementations, the relative positioning of the metal plate <NUM> and the metal feed line <NUM> within the resonant cavity <NUM> can vary.

The center frequency and bandwidth of a first frequency band supported by the antenna assembly <NUM> are functions of at least the dielectric constant of the dielectric material and the depth and cross-sectional size of the resonant cavity <NUM> (e.g., as cut across the center axis). The center frequency and bandwidth of a second frequency band supported by the antenna assembly <NUM> are functions of at least the dielectric constant of the dielectric material, the size of the metal plate <NUM> (e.g., as measured across the center axis) and the depth of the metal plate <NUM> within the resonant cavity <NUM>. In one implementation, the metal plate <NUM> is approximately <NUM> thick, subject to manufacturing tolerances, although other thicknesses may be employed.

The impedance matching of the antenna assembly <NUM> is a function of at least the dielectric constant of the dielectric material, the depth of the metal feed line <NUM> in the resonant cavity <NUM> and the geometry of the metal feed line <NUM>. In the illustrated implementation, the geometry of the metal feed line <NUM> includes a coupling stub <NUM>, which operates as an inductor to set the impedance matching in the antenna assembly <NUM>.

In one implementation, in which a radius at the major axis of the aperture is <NUM> and the radius at the minor axis of the aperture is <NUM>, an example metal plate has a radius at the major axis of <NUM> and a radius at a minor radius of <NUM>. In some example implementations, the resonant cavity <NUM> is <NUM>-<NUM> deep, the metal plate <NUM> is <NUM>-<NUM>. mm thick and positioned at a <NUM>-<NUM> depth within the resonant cavity <NUM>, and the metal feed line <NUM> is positioned at a <NUM>-<NUM> distance from the metal plate <NUM> within the resonant cavity <NUM>. In one implementation, the metal feed line <NUM> is <NUM> long, with a coupling stub <NUM> long. Other configurations and dimensions may be employed to result in the same or different center frequencies and different bandwidths.

<FIG> illustrates a plan view of an example antenna assembly <NUM> operating predominantly within a first frequency band, and <FIG> illustrates a corresponding cross-sectional view A-A of the example antenna assembly <NUM> of <FIG> also includes a schematic representation of a radio frequency signal source <NUM>, and <FIG> also include arrows depicting capacitive coupling between a metal feed line <NUM> and a metal plate <NUM> (as shown by arrows <NUM>) and between the metal plate <NUM> and a resonant cavity <NUM> (as shown by arrows <NUM>).

As illustrated, the resonant cavity <NUM> presents an oblong aperture in the surface of a metal frame <NUM> and extends through the thickness of the metal frame <NUM>. In the illustrated implementations, the resonant cavity <NUM> of each antenna assembly extends completely through the metal frame <NUM> (e.g., presenting opposing apertures on opposing surfaces of the metal frame <NUM>, although in some implementations, one or more of the resonant cavities in an array may not extend completely through the metal frame <NUM> (e.g., the resonant cavity <NUM> may be open on one surface of the metal frame <NUM> and closed on the opposing surface of the metal frame <NUM>). The metal feed line <NUM> is positioned within the resonant cavity <NUM>, and the metal plate <NUM> is positioned between the metal feed line <NUM> and a surface of the metal frame <NUM>. The metal plate <NUM> is also centered at a center axis <NUM> of the resonant cavity <NUM>. Both the metal plate <NUM> and the metal feed line <NUM> are positioned orthogonal to the center axis <NUM>. In some implementations, one or more of the metal plate <NUM> and the metal feed line <NUM> may be positioned off-center with respect to the center axis of the resonant cavity <NUM> (in one or more dimensions) and may be off-orthogonal by less than <NUM>°, less than <NUM>°, less than <NUM>°, and by more than <NUM>° with respect to the center axis of the resonant cavity <NUM>.

A non-gaseous dielectric material substantially fills the resonant cavity <NUM>, suspending the metal plate <NUM> and the metal feed line <NUM> and maintaining electrical separate among the metal plate <NUM>, the metal feed line <NUM>, and the interior surface <NUM> of the resonant cavity <NUM>. It should be understood that alternative configurations may be employed, including without limitation configurations with off-center positioning, different relative positions, and substantially square apertures.

In the capacitive coupling illustrated in <FIG>, the radio frequency signal source <NUM> galvanically drives the metal feed line <NUM> to resonate and capacitively drive the metal plate <NUM>, which in turn resonates and capacitively drives the resonant cavity <NUM> at a center frequency within a first frequency band.

<FIG> illustrates a plan view of an example antenna assembly <NUM> operating predominantly within a second frequency band, and <FIG> illustrates a corresponding cross-sectional view A-A of the example antenna assembly <NUM> of <FIG> also includes a schematic of a representation of a radio frequency signal source <NUM>, and <FIG> also includes arrows <NUM> depicting capacitive coupling between a metal feed line <NUM> and a resonant cavity <NUM>.

As illustrated, the resonant cavity <NUM> presents an oblong aperture in the surface of a metal frame <NUM> and extends through the thickness of the metal frame <NUM>. The metal feed line <NUM> is positioned within the resonant cavity <NUM>, and the metal plate <NUM> is positioned between the metal feed line <NUM> and a surface of the metal frame <NUM>. The metal plate <NUM> is also centered at a center axis <NUM> of the resonant cavity <NUM>. Both the metal plate <NUM> and the metal feed line <NUM> are positioned orthogonal to the center axis <NUM>. A non-gaseous dielectric material substantially fills the resonant cavity <NUM>, suspending the metal plate <NUM> and the metal feed line <NUM> and maintaining electrical separate among the metal plate <NUM>, the metal feed line <NUM>, and the interior surface <NUM> of the resonant cavity <NUM>. It should be understood that alternative configurations may be employed, including without limitation configurations with off-center positioning, different relative positions, and substantially square apertures.

In the capacitive coupling illustrated in <FIG>, the radio frequency signal source <NUM> galvanically drives the metal feed line <NUM> to resonate and capacitively drive the resonant cavity <NUM> at a center frequency within a second frequency band, which is different than the first frequency band of the configuration shown in <FIG>.

<FIG> illustrates example operations <NUM> for selectively driving hybrid antenna assemblies of a computing device. Each antenna assembly includes a metal frame including a resonant cavity having a center axis and defining a volume within the metal frame, a metal plate positioned within the volume orthogonal to the center axis of the resonant cavity, and a metal feed line. In one implementation, the antenna assemblies are configured in an array along an exterior surface of the computing device, such as at an edge of the computing device.

A signaling operation <NUM> selective feeds a radio frequency signal from a radio frequency signal source to a metal feed line of one of the antenna assemblies. The radio frequency signal is centered at a first frequency or a second frequency. Depending on the frequency at which the radio frequency signal is centered (as illustrated by block <NUM>), a driving operation <NUM> or a driving operation <NUM> is performed. The driving operation <NUM> capacitively drives the resonant cavity of the antenna assembly from the metal feed line predominantly in a first frequency band. The driving operation <NUM> capacitively drives the metal plate of the antenna assembly by the metal feed line, and the metal plate resonates to capacitively drive the resonant cavities to resonate predominantly in a second frequency band. A scanning operation <NUM> scans the radio frequency signal to another antenna assembly.

<FIG> illustrates a graph <NUM> of return loss <NUM> across a range of frequencies of an example antenna assembly of the described technology. As shown in the graph <NUM>, the return loss <NUM> centered at <NUM> and <NUM> is about -<NUM> dB, and between those two center frequencies, the return loss <NUM> does not rise above -<NUM> dB. Accordingly, the performance of the example antenna assembly provides good performance across a wide range of frequencies, thereby supporting antenna operation at both center frequencies without modification of the physical structure of the example antenna assembly.

An example antenna assembly includes a metal frame including a resonant cavity, wherein the resonant cavity has a center axis and defines a volume within the metal frame, a metal plate positioned within the volume on the center axis of the resonant cavity, and a metal feed line positioned to capacitively drive the metal plate and the resonant cavity, wherein at least a portion of the metal feed line is positioned within the volume on the center axis of the resonant cavity.

Another example antenna assembly of any preceding antenna assembly is provided wherein the metal frame forms an exterior surface of a computing device.

Another example antenna assembly of any preceding antenna assembly is provided wherein the center axis of the resonant cavity extends orthogonally between a first surface of the metal frame and an opposite second surface of the metal frame.

Another example antenna assembly of any preceding antenna assembly is provided wherein the resonant cavity forms an oblong aperture in a surface of the metal frame.

Another example antenna assembly of any preceding antenna assembly is provided wherein the resonant cavity has an interior surface, and the antenna assembly further includes a non-gaseous dielectric material within the resonant cavity, the non-gaseous dielectric material maintaining separation among the metal plate, the metal feed line, and the interior surface of the resonant cavity.

Another example antenna assembly of any preceding antenna assembly further includes a radio frequency signal source electrically connected to the metal feed line, the metal feed line being positioned to capacitively drive the resonant cavity.

Another example antenna assembly of any preceding antenna assembly further includes a radio frequency signal source electrically connected to the metal feed line, the metal feed line being positioned to capacitively drive the metal plate to capacitively drive the resonant cavity.

Another example antenna assembly of any preceding antenna assembly further include a radio frequency signal source electrically connected to the metal feed line, the metal feed line being positioned to capacitively drive the resonant cavity predominantly in a first frequency band and to capacitively drive the metal plate to capacitively drive the resonant cavity predominantly in a second frequency band.

In a further example, the width and a center frequency of the first frequency band are dependent upon the size of the resonant cavity.

In one example, the width and a center frequency of the second frequency band are dependent upon the size of the metal plate and the depth the metal plate is positioned within the resonant cavity from an exterior surface of the metal frame.

In one example, the ranges of the first frequency band and the second frequency band are dependent upon impedance matching contributions of a geometry of the at least a portion of the metal feed line within the resonant cavity and the position of the metal feed line along the center axis.

An example computing device includes a metal frame forming an exterior surface of the computing device and including an array of resonant cavities, wherein each resonant cavity has a center axis and defines a volume within the metal frame. Each volume contains a corresponding metal plate positioned within the volume on the center axis of the resonant cavity, and a corresponding metal feed line positioned to capacitively drive the corresponding metal plate and the resonant cavity, wherein at least a portion of the corresponding metal feed line is positioned within the volume on the center axis of the resonant cavity.

Another example computing device of any preceding computing system is provided wherein each resonant cavity forms an oblong aperture in a surface of the metal frame.

Another example computing device of any preceding computing system is provided wherein each resonant cavity has an interior surface, and the computing device further includes a non-gaseous dielectric material within each resonant cavity, the non-gaseous dielectric material maintaining separation among the corresponding metal plate, the corresponding metal feed line, and the interior surface of the resonant cavity.

Another example computing device of any preceding computing system further includes a radio frequency signal source electrically connectable to the corresponding metal feed line of each resonant cavity, the corresponding metal feed line being positioned to capacitively drive the resonant cavity predominantly in a first frequency band and to capacitively drive the corresponding metal plate to capacitively drive the resonant cavity predominantly in a second frequency band.

Another example computing device of any preceding computing system is provided wherein the width and a center frequency of the first frequency band are dependent upon the size of the resonant cavity.

Another example computing device of any preceding computing system is provided wherein the width and a center frequency of the second frequency band are dependent upon the size of the metal plate and the depth the metal plate is positioned within the resonant cavity from an exterior surface of the metal frame.

Another example computing device of any preceding computing system is provided wherein the ranges of the first frequency band and the second frequency band are dependent upon impedance matching contributions of a geometry of the at least a portion of the metal feed line within the resonant cavity and the position of the metal feed line along the center axis.

An example method of selectively driving antenna assemblies of a computing device is provided. Each antenna assembly includes a metal frame including a resonant cavity having a center axis and defining a volume within the metal frame, a metal plate positioned within the volume on the center axis of the resonant cavity, and a metal feed line. The example method includes selectively setting a radio frequency signal source electrically connected to at least one of the metal feed lines to provide a radio frequency signal having one of a first frequency and a second frequency. The example method also includes capacitively driving at least one of the metal plates by the at least one of the metal feed lines at the first frequency, the at least one of the metal plates resonating to capacitively drive at least one of the resonant cavities to resonate predominantly in a first frequency band, and capacitively driving the at least one of the resonant cavities by the at least one of the metal feed lines at the second frequency to resonate predominantly in a second frequency band.

Another example method of any preceding method is provided wherein the capacitively driving operations includes scanning the radio frequency signal across the metal feed lines of the antenna assemblies.

An example system for selectively driving antenna assemblies of a computing device is provided. Each antenna assembly includes a metal frame including a resonant cavity having a center axis and defining a volume within the metal frame, a metal plate positioned within the volume on the center axis of the resonant cavity, and a metal feed line. The example system includes means for selectively setting a radio frequency signal source electrically connected to at least one of the metal feed lines to provide a radio frequency signal having one of a first frequency and a second frequency. The example system also includes means for capacitively driving at least one of the metal plates by the at least one of the metal feed lines at the first frequency, the at least one of the metal plates resonating to capacitively drive at least one of the resonant cavities to resonate predominantly in a first frequency band, and means for capacitively driving the at least one of the resonant cavities by the at least one of the metal feed lines at the second frequency to resonate predominantly in a second frequency band.

Another example system of any preceding system is provided wherein the means for capacitively driving operations includes means for scanning the radio frequency signal across the metal feed lines of the antenna assemblies.

Claim 1:
An antenna assembly (<NUM>), for operation between <NUM> to <NUM>, comprising:
a metal frame (<NUM>) including a resonant cavity (<NUM>), the resonant cavity defining a volume within the metal frame and having a center axis extending between a first surface of the metal frame and an opposite second surface of the metal frame;
a metal plate (<NUM>) positioned within the volume on the center axis of the resonant cavity; and
a metal feed line (<NUM>) positioned to capacitively drive the metal plate and the resonant cavity, at least a portion of the metal feed line being positioned within the volume on the center axis of the resonant cavity.