Patent Application
20140347225
Antennas for computing devices present challenges relating to receiving and transmitting radio waves at one or more select frequencies. These challenges are magnified by a current trend of housing such computing devices (and their antennas) in metal cases, as the metal cases tend to shield incoming and outgoing radio waves. Some attempted solutions to mitigate this shielding problem introduce structural and manufacturing challenges into the design of the computing device.
Implementations described and claimed herein address the foregoing problems by forming an antenna assembly from a portion of the metal computing device case as a primary radiating structure. A metal computing device case includes one or more metal side faces bounding at least a portion of the metal back face. The metal computing device case includes a radiating structure including an exterior metal surface of the metal computing device case. The metal computing device case substantially encloses electronics of a computing device. The exterior metal surface is a metal plate insulated from the rest of the metal computing device case by a dielectric insert filling slots between the metal plate and the rest of the metal computing device case. The radiating structure also includes a ceramic block spaced from a metal plate by a dielectric spacer. The metal plate is insulated from the rest of the metal computing device case and is capacitively coupled with the ceramic block.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
Other implementations are also described and recited herein.
The metal back face 102 and various metal side faces generally form a back section of the metal computing device case 100 in which electronic and mechanical components of the computing device are located. A front face (not shown) typically includes a display surface, such as a touch screen display. The front face is assembled to the back section of the metal computing device case 100 to enclose the electronic components of the computing device, including at least one processor, tangible storage (e.g., memory, magnetic storage disk), display electronics, communication electronics, etc.
In one implementation, the antenna structure 108 is located at an exterior surface of the metal computing device case 100, such that an exposed portion of the metal computing device case 100 (e.g., metal plate 110) that performs as a part of a radiating structure for operation of the antenna structure 108. The metal plate 110 and the rest of the side face 104 may act as a radiating structure. In other implementations, the antenna structure 108 may include a metal plate 110 that is not a portion of the metal computing device case 100 but is a separate metal plate (possibly of a different metallic or composite composition) forming, in combination with the metal side face 104, a back section of the enclosed metal computing device case 100. Such a radiating structure may be designed to resonate at a particular frequency, and/or, for certain applications, may be designed to radiate very limited, or substantially zero, power at a particular frequency or set of frequencies.
The cut-out slots 112, 114, and 116 are filled by a dielectric material (e.g., plastic), providing insulation between the metal plate 110 and the metal side face 104 and the metal back face 102 and closing gaps in the metal computing device case 100. In some implementations, the insert may have a voltage-dependent dielectric constant. The metal plate 110 is also insulated from contact with the front face of the computing device. Although not shown, the four edge of the metal plate 110 may also be insulated from the metal computing device case 100, such as by a fourth edge of dielectric material, an insulating gasket, contact with a glass layer in the front section of the computing device, etc. The separation of the metal plate 110 from the rest of the metal computing device case 100 and the exterior exposure of the metal plate 110 provides low coupling to other antennas within the metal computing device case 100 and to the metal computing device 100 itself.
The metal computing device case 100 is shown with abrupt corners between the metal side faces 104, 106 and the metal back face 102. In other implementations, fewer than four sides may partially bound the metal back face 102. In addition, the metal back face 102 and one or more of the metal side faces may be joined at an abrupt corner, at a curved corner (e.g., a continuous arc between the metal back face and the metal side face), or in various continuous intersecting surface combinations. Furthermore, the metal side faces need not be perpendicular to the metal back face (e.g., a metal side face may be positioned at an obtuse or acute angle with the metal back face). In one implementation, the metal back face and one or more metal side faces are integrated into a single piece construction, although other assembled configurations are also contemplated.
In one implementation, the width of each slot 112, 114, and 116 is 2 mm, with the slots 112 and 114 being 8 mm long and the slot 116 being 29 mm. Nevertheless, it should be understood that other dimensions and configurations may be employed. The plastic insert in the slots and otherwise surrounding the metal plate 110 insulate or isolate the metal plate from the rest of the metal computing device case 100, which may be grounded.
As illustrated, the antenna structure 208 includes metal plate 210 (e.g., part of the metal side face 204 of the metal computing device case or another metal plate) separated from the metal side face 204 and the metal back face by two cut-out side slots 212 and 214 and a back slot (not shown) between the metal plate 210 and the metal back face. The exterior surface of the metal plate 210 is exposed (e.g., the surface of the metal plate 210 is exposed to a user's environment, touchable by a user, etc.), and the interior surface of the metal plate 210 is coupled to a feed structure (not shown) within the interior of the computing device 200. It should be understood that multiple such antenna structures may be formed in the metal back face 202 or any metal side face of the metal computing device case.
In one implementation, the antenna structure 208 is located at an exterior surface of the metal computing device case, such that an exposed portion of the metal computing device case (e.g., metal plate 210) performs as a part of a radiating structure for operation of the antenna structure 208. In other implementations, the antenna structure 208 may include a metal plate 210 that is not a portion of the metal computing device case but is a separate metal plate (possibly of a different metallic or composite composition) forming, in combination with the metal side face 204, the enclosed metal computing device case.
The cut-out slots 212, 214, and the back slot are filled by a dielectric material (e.g., plastic), providing insulation between the metal plate 210 and the metal side face 204 and the metal back face and closing gaps in the metal computing device case. In some implementations, the insert may have a voltage-dependent dielectric constant. The metal plate 210 is also insulated from contact with the front face of the computing device 200. It should be understood that, although not shown, the four edge of the metal plate 210 is also insulated from the metal computing device case, such as by a fourth edge of dielectric material, an insulating gasket, contact with a glass layer in the front section of the computing device 200, etc.
As described with regard to
A high dielectric constant ceramic block 314 is capacitively coupled across a dielectric spacer 316 and fed by a feed structure 317 that is electrically connected between a radio 318 and a metallized surface 319 on the ceramic block 314. The ceramic block 314 may operate as the only radiating structure or may operate as an active antenna in combination with the metal plate 306 and the rest of the surrounding metal computing device case acting as a parasitic antenna.
The metal plate 306 is connected to the ground plane of the metal back face 304 via a series and/or parallel resonant circuit 320 (e.g., including an inductor and/or a capacitor). The resonant circuit 320 allows for multi-band operation. For example, with the use of a high band or low pass filter, it is possible to enable multiple resonant frequencies during operation. In another example, the ceramic block 314 is the resonant structure and the resonant circuit 320 is configured as an open circuit at the frequency of the ceramic antenna. When the resonant circuit 320 is short-circuited, the metal plate 306 is driven by the capacitance of the dielectric material.
The ceramic block 314 provides a dielectric resonant antenna as a feed mechanism to excite the metal plate 306. In this configuration, the dielectric resonant antenna provides most of the near-field of the resonant frequency contained within the ceramic block 314, which improves immunity to hand effects and low coupling to other antennas within the contained system. Furthermore, the exposure of the metal plate 306 to the exterior of the metal computing device case reduces coupling to the metal computing device case itself and thereby increases efficiency of the antenna structure 300. An implementation providing a series resonant circuit 320 may be used to implement a dual-band antenna design.
A high dielectric constant ceramic block 414 is capacitively coupled across a dielectric spacer 416 and fed by a feed structure 417 that is electrically connected between a radio 418 and a metallized surface 419 on the ceramic block 414. The ceramic block 414 can operate as the only radiating structure or can operate as an active antenna in combination with the metal plate 406 and the rest of the surrounding metal computing device case acting as a parasitic antenna.
The metal plate 406 is connected to the ground plane of the metal back face 404 via a series inductor circuit 420. The series inductor circuit 420 allows inductive loading of the antenna, such that the antenna's operating frequency can be lowered without increasing the antenna size. The ceramic block 414 provides a dielectric resonant antenna as a feed mechanism to excite the metal plate 406. In this configuration, the dielectric resonant antenna provides most of the near-field of the resonant frequency contained within the ceramic block 414, which improves immunity to hand effects and low coupling to other antennas within the contained system. Furthermore, the exposure of the metal plate 406 to the exterior of the metal computing device case reduces coupling to the metal computing device case itself and thereby increases efficiency of the antenna structure 400. An implementation providing a series inductor circuit 420 may be used to implement a single-band antenna design for use in Global Positioning System (GPS) communications and Global Navigation Satellite System (GLONASS) communications. The use of the series inductor circuit 420 may also allow the slots 408, 410, and 412 to be thinner than in other configurations. The series inductor circuit 420 can also load the antenna with additional inductance, allowing the metal plate to be smaller for a given operational frequency or allowing a larger metal plate to operate at a lower frequency.
Various implementations of an antenna structure described herein include configuration having a capacitive feed/resonant dielectric antenna that excites an external metallic feature of the metal computing device case. The use of the dielectric resonant antenna as the feed mechanism provides that most of the near-field of the resonant frequency of the dielectric antenna is contained within the ceramic block, thereby increasing immunity to hand effects, providing lower coupling to other antennas within the contained system, and reducing shielding effects of the metal computing device case itself The described configurations may further reduce the amount of interior space occupied by the antenna structure, particularly at higher resonant frequencies.
A high dielectric constant ceramic block 514 is capacitively coupled across a dielectric spacer 516 and fed by a feed structure 517 that is electrically connected between a radio 518 and a metallized surface 519 on the ceramic block 514. The ceramic block 514 can operate as the only radiating structure or can operate as an active antenna in combination with the metal plate 506 and the rest of the surrounding metal computing device case acting as a parasitic antenna.
The metal plate 506 is connected to the ground plane of the metal back face 504 via a switched inductor circuit 520. As with the single inductor described with regard to
The ceramic block 514 provides a dielectric resonant antenna as a feed mechanism to excite the metal plate 506. In this configuration, the dielectric resonant antenna provides most of the near-field of the resonant frequency contained within the ceramic block 514, which improves immunity to hand effects and low coupling to other antennas within the contained system. Furthermore, the exposure of the metal plate 506 to the exterior of the metal computing device case reduces coupling to the metal computing device case itself and thereby increases efficiency of the antenna structure 500. Such example configurations may include addition of a switched inductor between the metal plate and the ground plane for low band resonant tuning and/or an automatic impedance matching circuit.
An exciting operation 604 excites the radiating structure in the metal computing device case causing the radiating structure to resonate at one or more resonance frequencies over time. In many configurations, the radiating structure provides excellent omnidirectional radiation performance.
It should also be understood that combinations of side faces and/or the back faces might form part of the radiating structure. For example, in one implementation, the metal plate is positioned in a cut-out in the back face, such that the back face and the metal plate form part of the radiating structure. In other implementations, the metal plate is positioned in such a way that one or more side faces and the back face form part of the radiating structure.
The above specification, examples, and data provide a complete description of the structure and use of exemplary implementations. Since many implementations can be made without departing from the spirit and scope of the claimed invention, the claims hereinafter appended define the invention. Furthermore, structural features of the different examples may be combined in yet another implementation without departing from the recited claims.
The present application claims benefit to U.S. Provisional Application No. 61/827,372, filed on May 24, 2013 and entitled “Back Face Antenna in a Computing Device Case,” and U.S. Provisional Application No. 61/827,421, filed on May 24, 2013 and entitled “Side Face Antenna in a Computing Device Case,” both of which are specifically incorporated by reference for all that they disclose and teach. The present application is also related to U.S. application Ser. No. ______, filed concurrently herewith and entitled “Back Face Antenna in a Computing Device Case” [Docket No. 339458.02], and U.S. application Ser. No. ______ filed concurrently herewith and entitled Side Face Antenna in a Computing Device Case” [Docket No. 339459.02], both of which are specifically incorporated by reference for all that they disclose and teach.
| Number | Date | Country | |
|---|---|---|---|
| 61827372 | May 2013 | US | |
| 61827421 | May 2013 | US |
