Patent Description:
The described technology provides a communication device including a metal chassis, a printed circuit board positioned within the metal chassis, and a hybrid cavity mode antenna. The hybrid cavity mode antenna includes a conductive wall defining at least a portion of a cavity, wherein the cavity is further defined by one or more surfaces of the metal chassis and the printed circuit board, and an electrically-fed antenna configured to radiate a first radiofrequency signal in a first frequency range. The electrically-fed antenna is electrically driven from the printed circuit board of the communication device. The electrically-fed antenna is positioned within the cavity to drive the cavity to radiate a second radiofrequency signal in a second frequency range.

This summary is provided to introduce a selection of concepts in a simplified form that is further described below in the Detailed Description.

An example antenna design provides a hybrid method of using a loop antenna to excite a first radiofrequency signal (e.g., at a <NUM> antenna response) and a cavity mode antenna defined at least in part by the metal chassis of a communication device to excite a second radiofrequency signal (e.g., at a <NUM> antenna response). The loop antenna is positioned within the cavity mode antenna bounds. With this antenna topology, no slots are needed in the metal chassis of the communication device to provide communications at these radiofrequency ranges, providing an industrial design look that is highly desirable and mechanical strength advantages over all previous designs.

<FIG> illustrates a communication device <NUM> including an example hybrid cavity mode antenna <NUM> having a loop antenna <NUM> and a cavity mode antenna <NUM>. The loop antenna is electrically-fed an RF signal from a transmitter of the communication device <NUM>. The example hybrid cavity mode antenna <NUM> is positioned within a metal chassis <NUM> of the communication device <NUM> and inductively and/or capacitively fed by the loop antenna <NUM>. In <FIG>, the metal chassis <NUM> defines at least a portion of a cavity <NUM> (e.g., two metal edge surfaces <NUM> and <NUM> and a back surface of the metal chassis <NUM> define at least two side walls and a back or bottom wall of the cavity <NUM>, respectively). The communication device <NUM> also includes a display <NUM> and a printed circuit board <NUM> having a ground plane. The ground plane of the printed circuit board <NUM> defines a fourth wall of the cavity <NUM>. Additional walls of the cavity <NUM> are defined by a conductive wall <NUM>, which is described in more detail with regard to <FIG>, <FIG>, and <FIG>. In one implementation, the conductive wall <NUM> includes two grounding wall connectors <NUM> and <NUM> and a metal foam section (indicated by the dashed line connecting the two grounding wall connectors <NUM> and <NUM>), although other implementations are contemplated, including without limitation a structural metal wall extending across the metal back surface from the first metal edge surface to the second metal edge surface (see <FIG>). In one implementation, the surfaces of the cavity <NUM> are electrically grounded.

The display <NUM> and some of its constituent components (collectively, the "display assembly") act to substantially shield radiofrequency (RF) radiation from exiting the communication device <NUM>. In this manner, the display assembly is considered "RF opaque" with respect to RF radiation passing between the interior and exterior of the communication device <NUM>, although this term may apply to materials or components that do not block all such radiation (e.g., a material blocking substantially all or most of the RF radiation may be considered RF opaque).

Accordingly, the example hybrid cavity mode antenna <NUM> is positioned at or near a bezel region <NUM> in which the shielding material is not located. Instead, the bezel region <NUM> is considered "RF transparent" because it passes most or all of the RF radiation between the interior and exterior of the communication device <NUM>, although this term may apply to materials or components that do block some amount of such radiation (e.g., a material passing substantially all or most of the RF radiation may be considered RF transparent or even RF translucent). An opening between the printed circuit board <NUM> and the metal chassis <NUM> presents a radiating slot in the cavity <NUM> from which a radiofrequency signal can radiate. The radiating slot is positioned to overlap or predominantly overlap the bezel region <NUM>. As such, the described implementation can operate as a cavity-backed slot antenna. The loop antenna <NUM> is positioned within the cavity, operating at approximately <NUM> and driving the cavity and the radiating slot at approximately <NUM>.

As shown in the expanded view <NUM>, the example hybrid cavity mode antenna <NUM> is positioned near the edge of the communication device <NUM>, with the loop antenna <NUM> positioned in the bezel region <NUM> so that RF radiation may pass between the interior and exterior of the communication device <NUM> through the RF transparent bezel region <NUM>. The loop antenna <NUM> is also positioned within the cavity <NUM> to excite the cavity mode of the cavity <NUM>. It should be noted that the cavity <NUM> is also positioned at or near the bezel region <NUM> to radiate through the RF transparent materials of the bezel region <NUM>.

A second hybrid cavity mode antenna <NUM> is also shown between the metal edge surface <NUM> and another metal edge surface <NUM>. Additional hybrid cavity mode antennas may be employed in the same communication device <NUM>. In addition, the locations of such hybrid cavity mode antennas may also vary from those illustrated implementations. For example, a hybrid cavity mode antenna may be positioned against the side of the metal chassis, rather than in the corner of the metal chassis.

<FIG> illustrates a perspective view of an example hybrid cavity mode antenna <NUM> in a communication device <NUM>. All or most of the components of the communication device <NUM> are contained within a metal chassis <NUM>. The bounds of a cavity of the hybrid cavity mode antenna <NUM> are defined in two dimensions by the conductive wall <NUM> (including the grounding connectors <NUM> and <NUM>), a first metal edge surface <NUM> of the metal chassis <NUM>, and a second metal edge surface <NUM> of the metal chassis <NUM>. The bottom surface of the cavity is defined by the back metal surface of the metal chassis <NUM>, and the top surface of the cavity is defined by the ground plane of the printed circuit board (PCB <NUM>). An opening between the PCB <NUM> and the first metal edge surface <NUM> or the second metal edge surface <NUM> defines a radiating slot <NUM> in the cavity. One or more electrically-fed antennas are positioned within the cavity. In <FIG>, a loop antenna <NUM> is electrically driven by a feed from the PCB <NUM> to radiate with a first radiofrequency range (e.g., encompassing <NUM>) and is positioned within the cavity to inductively couple (and/or capacitively couple) into the cavity mode of the resulting cavity mode antenna at a second radiofrequency range (e.g., encompassing <NUM>). A second loop antenna <NUM> is also shown to the left of the cavity. Example electrically-fed antennas may include without limitation loop antennas and monopole antennas.

In <FIG>, the conductive wall <NUM> defines a portion of a cavity surface under the PCB <NUM>. The conductive wall <NUM> can include one or more grounding wall connectors (see grounding wall connectors <NUM> and <NUM>) that electrically connect the ground plane of the PCB <NUM> and the conductive wall <NUM> to the metal chassis <NUM> of the communication device <NUM>. The dimensions of the cavity, as substantially defined by the metal chassis <NUM>, the ground plane of the PCB <NUM>, the conductive wall define the volume of the cavity and therefore contribute to the second radiofrequency range in which the cavity radiates.

A cavity-driving antenna may capacitively and/or inductively coupled with the cavity to drive the cavity to radiate. Various implementations may include multiple cavity-driving antennas. For example, in one implementation, two loop antennas are positioned within the cavity on opposing sides of the cavity. In other examples, one or more monopole antennas may be used to drive the cavity. In addition, multiple hybrid cavity mode antennas may be implemented in a single communication device.

In some implementations, the conductive wall <NUM> includes tuning circuitry <NUM>, such as one or more inductive and/or capacitive elements, any of which may be variable or switchable in order to dynamically adjust the tuning of the cavity antenna. It should also be understood that another electrically-conductive material may be used in place of metal for the chassis, foam, and other components. One or more tuning circuits may be employed at various locations on the cavity walls.

<FIG> illustrates a top view and three cross-sectional views of an example hybrid cavity mode antenna <NUM>. The example hybrid cavity mode antenna <NUM> in a communication device includes a loop antenna <NUM> and a cavity antenna, the dimensions of which are defined by the cavity <NUM>. The loop antenna <NUM> and at least a portion of the cavity <NUM> are positioned at or near the bezel region <NUM> of communication device between the display <NUM> (covered by a cover glass <NUM>) and the side walls <NUM> and/or <NUM> of a metal chassis of the communication device. In one implementation, the loop antenna <NUM> radiates at a radiofrequency signal in a first radiofrequency range (e.g., <NUM>).

In this top plan view of <FIG>, the dimensions of the cavity <NUM> are defined by the side walls <NUM> and <NUM> of the metal chassis of the communication device, the back wall <NUM> of the metal chassis, two grounding wall connectors <NUM> and <NUM>, and the ground plane of a printed circuit board <NUM>. A conductive wall <NUM> connects the two grounding wall connectors <NUM> and <NUM>, the back wall <NUM> of the metal chassis, and the ground plane of the printed circuit board <NUM>. In one implementation, the conductive wall <NUM> is formed from a metal foam, which is both structural and rigid, although other conductive wall structures are contemplated, including without limitation one or more metal or otherwise conductive plates soldered to the printed circuit board <NUM> and the chassis surfaces. In one implementation, the loop antenna <NUM> is positioned within the cavity <NUM> and inductivity couples with the cavity <NUM> to radiate the cavity <NUM> (as a cavity antenna) at a radiofrequency signal in a second radiofrequency range (e.g., <NUM>). The grounding wall connectors <NUM> and <NUM> can also be made of a metal foam, one or more conductive plates, etc..

<FIG> illustrates characteristics <NUM> of an example hybrid cavity mode antenna. Lines <NUM> and <NUM> represent antenna impedances of two different loop antennas, each positioned within the cavity mode antenna, respectively. The line <NUM> represents the return loss of a loop antenna positioned to the left of the cavity when the cavity is viewed as shown in the plan view of <FIG>. The line <NUM> represents the return loss of a loop antenna positioned to the right of the cavity when the cavity is viewed as shown in the plan view of <FIG> (e.g., where the loop antenna <NUM> is shown in <FIG>). The line <NUM> represents the isolation between the two antennas, where the lower the isolation, the more efficient the two antennas operate.

<FIG> illustrates an example communication device <NUM> for implementing the features and operations of the described technology. The communication device <NUM> may be a client device, such as a laptop, mobile device, desktop, tablet; a server/cloud device; an internet-of-things device; an electronic accessory; or another electronic device. The communication device <NUM> includes one or more processor(s) <NUM> and a memory <NUM>. The memory <NUM> generally includes both volatile memory (e.g., RAM) and non-volatile memory (e.g., flash memory). An operating system <NUM> resides in the memory <NUM> and is executed by the processor(s) <NUM>.

In an example communication device <NUM>, as shown in <FIG>, one or more modules or segments, such as communication software <NUM>, application modules, and other modules, are loaded into the operating system <NUM> on the memory <NUM> and/or storage <NUM> and executed by processor(s) <NUM>. The storage <NUM> may store communication parameters and other data and be local to the communication device <NUM> or may be remote and communicatively connected to the communication device <NUM>.

The communication device <NUM> includes a power supply <NUM>, which is powered by one or more batteries or other power sources and which provides power to other components of the communication device <NUM>. The power supply <NUM> may also be connected to an external power source that overrides or recharges the built-in batteries or other power sources.

The communication device <NUM> may include one or more communication transceivers <NUM> which may be connected to one or more antenna(s) <NUM> to provide network connectivity (e.g., mobile phone network, Wi-Fi®, Bluetooth®) to one or more other servers and/or client devices (e.g., mobile devices, desktop computers, or laptop computers). The communication device <NUM> may further include a network adapter <NUM>, which is a type of communication device. The communication device <NUM> may use the adapter and any other types of communication devices for establishing connections over a wide-area network (WAN) or local-area network (LAN). It should be appreciated that the network connections shown are exemplary and that other communication devices and means for establishing a communications link between the communication device <NUM> and other devices may be used.

The communication device <NUM> may include one or more input devices <NUM> such that a user may enter commands and information (e.g., a keyboard or mouse). These and other input devices may be coupled to the server by one or more interfaces <NUM>, such as a serial port interface, parallel port, or universal serial bus (USB). The communication device <NUM> may further include a display <NUM>, such as a touch screen display.

The communication device <NUM> may include a variety of tangible processor-readable storage media and intangible processor-readable communication signals. Tangible processor-readable storage can be embodied by any available media that can be accessed by the communication device <NUM> and includes both volatile and nonvolatile storage media, removable and non-removable storage media. Tangible processor-readable storage media excludes intangible communications signals and includes volatile and nonvolatile, removable and non-removable storage media implemented in any method or technology for storage of information such as processor-readable instructions, data structures, program modules or other data. Tangible processor-readable storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CDROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other tangible medium which can be used to store the desired information and which can be accessed by the communication device <NUM>. In contrast to tangible processor-readable storage media, intangible processor-readable communication signals may embody processor-readable instructions, data structures, program modules or other data resident in a modulated data signal, such as a carrier wave or other signal transport mechanism. By way of example, and not limitation, intangible communication signals include signals traveling through wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared, and other wireless media.

<FIG> illustrates an example implementation of a hybrid cavity mode antenna in a communication device <NUM>. All or most of the components of the communication device <NUM> are contained within a metal chassis (or an otherwise electrically conductive chassis). A conductive wall <NUM> is shown connecting a first edge surface <NUM> of the metal chassis to a second edge surface <NUM> of the metal chassis, forming a cavity within the area <NUM>. The cavity is also bounded (above and below) by the bottom surface <NUM> of the metal chassis and a printed circuit board (not shown) of the communication device <NUM>. Such boundaries form a cavity volume. In <FIG>, the conductive wall <NUM> is constructed from metal plates, but one or more portions of the conductive wall <NUM> may be formed from metal foam or other conductive materials.

In the illustrated implementation, the cavity is bounded by a first side <NUM> of the conductive wall <NUM> of approximately <NUM> and a second side <NUM> of the conductive wall <NUM> of approximately <NUM>. The opening between the metal chassis and the printed circuit board presents a slot in the cavity from which a radiofrequency signal can radiate. As such, the described implementation can operate as a cavity-backed slot antenna. A feed antenna (such as a loop antenna or a monopole antenna) would be positioned within the cavity, operating at approximately <NUM> and driving the cavity and the radiating slot at approximately <NUM>.

Cavity dimensions and supported frequencies can vary in different implementations. In one implementation, <NUM> corresponds to a cavity mode in this design as <NUM> millimeters<NUM>, and <NUM> corresponds to a cavity mode in this design as <NUM> millimeters<NUM>, although other volumes, dimensions, and frequency band may be employed.

While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any inventions or of what may be claimed, but rather as descriptions of features specific to particular embodiments of a particular described technology.

Claim 1:
A communication device (<NUM>) comprising:
a metal chassis (<NUM>), wherein the metal chassis includes a metal back surface and at least a first metal edge surface and a second metal edge surface;
a printed circuit board (<NUM>) positioned within the metal chassis; and
a hybrid cavity mode antenna (<NUM>), the hybrid cavity mode antenna including:
a conductive wall (<NUM>) defining at least a portion of a cavity (<NUM>), wherein the cavity is further defined by the metal back surface, the first metal edge surface, the second metal edge surface, the printed circuit board and the conductive wall and wherein the conductive wall includes a tuning circuit connecting the conductive wall to at least one of the first metal edge surface and the second metal edge surface; and
an electrically-fed antenna (<NUM>) configured to radiate a first radiofrequency signal in a first frequency range, wherein the electrically-fed antenna is electrically driven from the printed circuit board of the communication device, the electrically-fed antenna being positioned within the cavity to drive the cavity to radiate a second radiofrequency signal in a second frequency range.