Patent Application
20140361931
This relates generally to electronic devices, and, more particularly, to antennas in electronic devices.
Electronic devices such as portable computers and handheld electronic devices are often provided with wireless communications capabilities. For example, electronic devices may have wireless communications circuitry to communicate using cellular telephone bands and to support communications with satellite navigation systems and wireless local area networks.
It can be difficult to incorporate antennas and other electrical components successfully into an electronic device. Some electronic devices are manufactured with small form factors, so space for components is limited. In many electronic devices, the presence of conductive structures can influence the performance of electronic components, further restricting potential mounting arrangements for components such as antennas.
It would therefore be desirable to be able to provide improved electronic device antennas.
An electronic device may be provided with a housing. An antenna window may be formed in the housing. The housing and the antenna window may have matching curved shapes.
An antenna with a curved shape that matches the curved shape of the antenna window may be mounted behind the antenna window. The antenna may have an antenna resonating element such as an inverted-F antenna resonating element and may have an antenna ground. The antenna resonating element may be formed from patterned metal traces on a flexible printed circuit. The antenna ground may be formed from a metal can that defines a cavity with an opening.
The flexible printed circuit may have ground traces that run along a peripheral edge of the flexible printed circuit. The metal can may have walls that surround a cavity with an opening. The metal can may have a lip formed from bent portions of the walls. The flexible printed circuit may cover the opening.
The flexible printed circuit may be bowed outwards away from the cavity so that the flexible printed circuit has a curved surface that matches the curved shape of the antenna window.
The flexible printed circuit may be soldered to the lip so that the ground traces are shorted to the can. A cable connector may be mounted on a bent tab in the flexible printed circuit. The lip may have a notch. The bent tab may pass through the notch. Solder may be used to attach the bent tab to one of the walls of the metal can. A cable connector may be soldered to the tab.
Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments.
Electronic devices may include antennas. The antennas may be used to support wireless communications such as cellular telephone communications, wireless local area network communications, peer-to-peer communications, satellite navigation system communications, and other wireless communications. Illustrative electronic devices that may be provided with antennas are shown in
Sensors, input-output devices, buttons, and other components such as connectors 30 may be mounted in housing 12. Connectors 30 may include audio jacks or other audio connectors, Universal Serial Bus connectors, Ethernet connectors, and other digital data port connectors, removable media connectors, and other connectors.
Antenna structures 32 (e.g., one or more antennas) may be mounted within the interior of device 10 (e.g., in the interior of housing 12). If desired, antenna 32 may have an antenna cavity. A conductive antenna ground structure with walls may surround and define a dielectric volume (sometimes referred to as an antenna cavity). The conductive structures that define the antenna cavity may be formed from a metal can or other conductive structures.
Antennas such as antenna 32 of
Electronic devices such as electronic devices 10 of
The configurations for device 10 that are shown in
Housing 12 of device 10, which is sometimes referred to as a case, may be formed of materials such as plastic, glass, ceramics, carbon-fiber composites and other fiber-based composites, metal (e.g., machined aluminum, stainless steel, or other metals), other materials, or a combination of these materials. Device 10 may be formed using a unibody construction in which most or all of housing 12 is formed from a single structural element (e.g., a piece of machined metal or a piece of molded plastic) or may be formed from multiple housing structures (e.g., outer housing structures that have been mounted to internal frame elements or other internal housing structures).
Display 14 may be a touch sensitive display that includes a touch sensor or may be insensitive to touch. Touch sensors for display 14 may be formed from an array of capacitive touch sensor electrodes, a resistive touch array, touch sensor structures based on acoustic touch, optical touch, or force-based touch technologies, or other suitable touch sensor components. Display 14 for device 10 may include display pixels formed from liquid crystal display (LCD) components, organic light-emitting diode components, or other suitable image pixel structures.
A schematic diagram of an illustrative configuration that may be used for electronic device 10 is shown in
Control circuitry 46 may include storage and processing circuitry for controlling the operation of device 10. Control circuitry 46 may, for example, include storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Control circuitry 46 may include processing circuitry based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio codec chips, application specific integrated circuits, etc.
Control circuitry 46 may be used to run software on device 10, such as operating system software and application software. Using this software, control circuitry 46 may, for example, transmit and receive wireless data, tune antennas to cover communications bands of interest, and perform other functions related to the operation of device 10.
Input-output devices 48 may be used to allow data to be supplied to device 10 and to allow data to be provided from device 10 to external devices. Input-output circuitry in devices 48 may include communications circuitry such as wired communications circuitry.
Input-output devices 48 may include input-output components with which a user can control the operation of device 10. A user may, for example, supply commands through input-output devices 48 and may receive status information and other output from device 10 using the output resources of input-output devices 48.
Input-output devices 48 may include sensors and status indicators such as an ambient light sensor, a proximity sensor, a temperature sensor, a pressure sensor, a magnetic sensor, an accelerometer, and light-emitting diodes and other components for gathering information about the environment in which device 10 is operating and providing information to a user of device 10 about the status of device 10. Audio components in devices 48 may include speakers and tone generators for presenting sound to a user of device 10 and microphones for gathering user audio input. Devices 48 may include one or more displays such as display 14. Displays may be used to present images for a user such as text, video, and still images. Sensors in devices 48 may include a touch sensor array that is formed as one of the layers in display 14. During operation, user input may be gathered using buttons and other input-output components in devices 48 such as touch pad sensors, buttons, joysticks, click wheels, scrolling wheels, touch sensors such as a touch sensor array in a touch screen display or a touch pad, key pads, keyboards, vibrators, cameras, and other input-output components.
Device 10 may use wireless circuitry 54 to communicate over one or more wireless communications bands. Wireless communications circuitry 54 may include radio-frequency (RF) transceiver circuitry such as transceiver circuitry 44 that is formed from one or more integrated circuits, power amplifier circuitry, low-noise input amplifiers, passive RF components, one or more antennas such as antenna structures 32, and other circuitry for handling RF wireless signals. Transceiver circuitry 44 may communicate with control circuitry 46 via path 50. Transceiver circuitry 44 may be used for handling cellular telephone communications, wireless local area network signals, and satellite navigation system signals such as signals at 1575 MHz from satellites associated with the Global Positioning System. Transceiver circuitry 44 may handle 2.4 GHz and 5 GHz bands for WiFi® (IEEE 802.11) communications or other wireless local area network communications and may handle the 2.4 GHz Bluetooth® communications band. Circuitry 44 may include cellular telephone transceiver circuitry for handling wireless communications in cellular telephone bands such as the bands in the range of 700 MHz to 2.7 GHz (as examples).
Wireless communications circuitry 54 can include circuitry for other short-range and long-range wireless links if desired. For example, wireless communications circuitry 54 may include wireless circuitry for receiving radio and television signals, paging circuits, etc. In WiFi® and Bluetooth® links and other short-range wireless links, wireless signals are typically used to convey data over tens or hundreds of feet. In cellular telephone links and other long-range links, wireless signals are typically used to convey data over thousands of feet or miles. Wireless communications circuitry 54 may also include circuitry for handing near field communications.
Wireless communications circuitry 54 may include antenna structures 32. Antenna structures 32 may include one or more antennas. Antenna structures 32 may include inverted-F antennas, slot antennas, patch antennas, loop antennas, monopoles, dipoles, single-band antennas, dual-band antennas, antennas that cover more than two bands, cavity antennas, or other suitable antennas.
To provide antenna structures 32 with the ability to cover communications frequencies of interest, antenna structures 32 may be provided with impedance matching circuitry, filter circuitry, and/or adjustable antenna circuitry. These circuits may be adjusted using control signals from control circuitry 46 that are provided to the circuits over one or more paths such as path 52.
Transceiver circuitry 44 may be coupled to antenna structures 32 by signal paths such as signal path 34. Signal path 34 may include one or more transmission lines. As an example, signal path 34 of
Transmission line 34 may be coupled to antenna feed structures associated with antenna structures 32. As an example, antenna structures 32 may form an inverted-F antenna having an antenna feed with a positive antenna feed terminal such as terminal 36 and a ground antenna feed terminal such as ground antenna feed terminal 38. Positive transmission line conductor 40 may be coupled to positive antenna feed terminal 36 and ground transmission line conductor 42 may be coupled to ground antenna feed terminal 38. Other types of antenna feed arrangements may be used if desired. The illustrative feeding configuration of
As shown in
Metal traces on a flexible printed circuit or other substrate may be used in implementing structures such as resonating element 54. Antenna ground 56 may be formed using metal traces on a flexible printed circuit or other substrate, using portions of housing 12 or other housing structures, using portions of internal device components, and using other conductive structures in device 10. As an example, antenna ground 56 may be formed from a metal can or other structure that forms a cavity for antenna 32. The can may be hollow and filled with a dielectric such as air and/or plastic. The metal can may have walls that define a cavity with an opening that faces the exterior of housing 12. Antenna resonating element 54 may be formed from patterned metal traces on a flexible printed circuit that is mounted in the metal can over the opening. The walls of the metal can may help to isolate the antenna from internal components in device 10, so that antenna performance is not sensitive to the presence and position of internal device components.
Housing 12 may be formed from plastic or other dielectric that is transparent to radio-frequency signals. If desired, housing 12 may be formed from conductive materials such as metal. In this type of configuration, a plastic insert or other structure formed from dielectric may be mounted within an opening in the metal housing to form an antenna window (i.e., a window in the housing that is transparent to radio-frequency antenna signals).
Openings such as hole 84 may be formed in flexible printed circuit 70. There may be, for example, a hole at each of the four corners of flexible printed circuit 70 (e.g., in a configuration of the type shown in
Antenna ground 56 may be formed from metal can 72. Can 72 may be a stamped sheet metal structure or may be formed using other techniques (e.g., welding, soldering, machining, stamping, die-cutting, molding, etc.). As shown in
Conductive material 78 (e.g., solder, conductive adhesive, metal in a welded structure, etc.) may be used to electrically and mechanically couple lip 76 of antenna can 72 to ring-shaped ground traces 80 on flexible printed circuit 70. Ground traces 80 may surround the periphery of flexible printed circuit 70 (i.e., ground traces 80 may run along the peripheral edge of flexible printed circuit 70) and may therefore sometimes be referred to as peripheral ground traces. Ground traces 80 may be formed on the lower surface of printed circuit 70 (and, if desired, other layers of flexible printed circuit 70) to short antenna ground traces 80 to lip 76 and other portions of can 72 in antenna ground 56. Lip 76 may have openings such as opening 82 that mate with respective openings 84 in flexible printed circuit 70. Screws may pass through openings 82 and 84 (e.g., to screw antenna 32 to an antenna window and/or metal housing 12).
Lip 76 may have a curved shape that mates with the curved shape of bent flexible printed circuit 70. This allows can 72 and flexible printed circuit 70 to be mounted flush with the curved interior surface of antenna window 64 or other curved structures in device 10. If desired, lip 76 and flexible printed circuit 70 may have other shapes (e.g., undulating shapes with multiple bends, planar shapes with no bends, convex shapes, concave shapes, etc.).
Antenna resonating element 54 may be formed from patterned antenna traces 68 on flexible printed circuit 70. Metal can 72 may form a cavity such as cavity 88. Can 72 and cavity 88 may have an opening such as opening 100 that faces outwards in direction 102 towards antenna window 64.
Antenna can 72 may be coupled to ground using conductive material 98 (e.g., conductive adhesive, solder, a conductive gasket, or other conductive material). As shown in
A connector such as a cable connector may be mounted to flexible printed circuit 70. As shown in
Flexible printed circuit 70 may be mounted to lip 76 of can 74 so that flexible printed circuit connector tab 106 and connector 104 are aligned with notch 76N in lip 76. Notch 76N may be formed from a rectangular opening or other gap in lip portion 76 of can 74 to accommodate bending of tab 106 downwards in direction 108. The underside of tab 106 may be provided with a rectangular metal trace that forms a ground pad. The ground pad may be soldered to portion 110 of wall 74 in can 72 after tab 106 has been bent downwards in direction 108. Tab 106 may have a rectangular shape, a semicircular shape, a triangular shape, or other suitable shape.
As shown in
A transmission line path such as cable 34 may have a first end such as end 114 and an opposing second end such as end 116. Connector 118 at end 114 may be coupled to mating connector 120 on printed circuit board 122. Components 124 such as radio-frequency transceiver circuitry 44 and other integrated circuits and devices may be mounted on printed circuit board 122. Printed circuit board 122 may be a flexible printed circuit, a rigid printed circuit board, or other substrate for mounting electrical components. At end 116, cable 34 may have a connector such as connector 128. Connector 128 may mate with connector 104 on flexible printed circuit tab 106, thereby coupling radio-frequency transceiver circuitry 44 to antenna 32.
Transmission line structures such as transmission line 34 and transmission line 112 may be implemented using printed circuit transmission line structures, coaxial cable transmission line structures, or other types of transmission line structures.
As shown in the top view of antenna structures 32 of
If desired, tunable components, filter components, matching network components, and other circuit components may be mounted on flexible printed circuit 70, as illustrated by component 144 of
The flexible printed circuit on which antenna resonating element structures for antenna resonating element 54 are formed may be shared with other circuitry such as radio-frequency transceiver circuitry, switching circuitry, filter circuitry, sensor circuitry, impedance matching circuitry, and circuitry not directly associated with wireless operations (e.g., microphones, sensors, filters, etc.).
The use of flexible printed circuits in forming antenna structures 32 allows the antenna resonating element and ground plane structures to be flexed to accommodate a curved structure such as a curved antenna window. For slightly curved or planar windows, a thin rigid printed circuit board such as a fiberglass-filled epoxy board (e.g., an FR4 board) or other substrate may also be used.
If desired, portions of a printed circuit antenna structure such as tail 140 of
The foregoing is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention.
