RF radiohead with optical interconnection to baseband processor

A portable electronic device includes a baseband integrated circuit configured to generate communication data and control signals. The portable electronic device also includes an optical path configured to be coupled to the baseband integrated circuit to transmit the data signals from the baseband integrated circuit. The portable electronic device additionally includes a radiohead configured to be coupled to the optical path to receive the data signals transmitted along the optical path from the baseband integrated circuit.

BACKGROUND

The present disclosure relates generally to use of transmitters in electronic devices.

Wireless communication devices (e.g., smartphones, wearable devices, etc.) are proliferating. Many wireless communication devices support multiple communication protocols on the same platform. For example, wireless communication devices may use Long-Term Evolution (LIE), Wideband Code Division Multiple Access (WCDMA), wireless local area networks (WLAN), Bluetooth, Global Positioning System (PPS), Near-Field Communication (NFC), and/or other suitable wireless communication protocols in addition to cellular/connectivity transceivers, such as radio frequency transceivers. Typically, radio frequency transceivers are located close to the cellular/connectivity baseband integrated circuits to avoid long routing lines between the transceivers and the baseband integrated circuits. However, the close proximity of the radio frequency transceiver to the baseband integrated circuit can lead to long RF routing lines across a device to one or more antenna(s) of the device (e.g., which are typically located at the opposite sides of the device) and, therefore, causes performance degradation (e.g., receive sensitivity degradation and/or increased current drain) and increased device cost (e.g., due to wiring complexities).

SUMMARY

In some embodiments, selective positioning of one or more radio frequency transceivers in a user device is undertaken. For example, placement of the one or more radio frequency transceivers may be adjacent or directly adjacent to one or more antennas of the device. As result, radio frequency performance impact (e.g., degradation) is reduced and/or minimized. Additionally, a single path may be utilized between any radio frequency transceiver and the baseband integrated circuit. In some embodiments, an optical path (e.g., a fiber optic or other optical path) may be utilized. In some embodiments, an optical connection (e.g., interface) may also be utilized at one or more of the radio frequency transceiver and the baseband integrated circuit. Use of the optical path may operate to reduce both interference to and from additional subsystems of the device. Additionally, the optical path may have sufficient bandwidth so that one optical interconnection between the radio frequency transceiver and the baseband integrated circuit is utilized. Moreover, the number of the interconnections between the radio frequency transceiver and the baseband integrated circuit can be reduced with accompanying gains in both reduced complexity and cost related to the interconnections.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

Typically a cellular/connectivity radio frequency transceiver is located close to the cellular/connectivity baseband integrated circuit (IC) to avoid long routing lines between the IC and the transceiver. In general, the routing lines include multiple metal wires, and may produce electromagnetic interference. However, when the radio frequency transceiver is located close to the cellular/connectivity baseband IC, transmission lines must travel the remaining distance to the antennas (which are typically located at the opposite sides of the device). These relatively long transmission lines may cause performance issues such as increased current drain and reception sensitivity degradation.

Accordingly, placement of the radio frequency transceiver in close proximity to the device antennas may instead be undertaken. As result, the radio frequency (RF) performance degradation may be reduced. An optical interconnection to the respective transceivers (each located proximate to a respective antenna) and the baseband IC may be used to reduce electromagnetic interference to other devices and subsystems. Similarly the sensitivity to interference coupling from other device subsystems is minimized through the use of optical fiber wire between the respective RF transceivers (each located proximate to a respective antenna) and the baseband IC.

With the foregoing in mind and referring first toFIG. 1, an electronic device10according to an embodiment of the present disclosure may include, among other things, one or more processor(s)12, memory14, nonvolatile storage16, a display18, input structures20, an input/output (I/O) interface22, a power source24, and network interface(s)26. The various functional blocks shown inFIG. 1may include hardware elements (e.g., including circuitry), software elements (e.g., including computer code stored on a computer-readable medium) or a combination of both hardware and software elements. It should be noted thatFIG. 1is merely one example of a particular implementation and is intended to illustrate the types of components that may be present in electronic device10.

In the electronic device10ofFIG. 1, the processor(s)12and/or other data processing circuitry may be operably coupled with the memory14and the nonvolatile storage16to perform various algorithms. Such programs or instructions, including those for executing the techniques described herein, executed by the processor(s)12may be stored in any suitable article of manufacture that includes one or more tangible, computer-readable media at least collectively storing the instructions or routines, such as the memory14and the nonvolatile storage16. The memory14and the nonvolatile storage16may include any suitable articles of manufacture for storing data and executable instructions, such as random-access memory, read-only memory, rewritable flash memory, hard drives, and/or optical discs. Also, programs (e.g., an operating system) encoded on such a computer program product may also include instructions that may be executed by the processor(s)12to enable the electronic device10to provide various functionalities.

In certain embodiments, the display18may be a liquid crystal display (e.g., LCD), which may allow users to view images generated on the electronic device10. In some embodiments, the display18may include a touch screen, which may allow users to interact with a user interface of the electronic device10. Furthermore, it should be appreciated that, in some embodiments, the display18may include one or more light emitting diode (e.g., LED) displays, or some combination of LCD panels and LED panels.

The input structures20of the electronic device10may enable a user to interact with the electronic device10(e.g., pressing a button to increase or decrease a volume level). The I/O interface22may enable the electronic device10to interface with various other electronic devices. The I/O interface22may include various types of ports that may be connected to cabling. These ports may include standardized and/or proprietary ports, such as USB, RS232, Apple's Lightning® connector, as well as one or more ports for a conducted RF link.

As further illustrated, the electronic device10may include a power source24. The power source24may include any suitable source of power, such as a rechargeable lithium polymer (e.g., Li-poly) battery and/or an alternating current (AC) or direct current (DC) power converter/inverter. The power source24may also be removable, such as a replaceable battery cell.

The network interface(s)26enable the electronic device10to connect to one or more network types and one or more other devices. The network interface(s)26may also include, for example, interfaces for a personal area network (e.g., PAN), such as a Bluetooth connection, for a local area network (e.g., LAN) or wireless local area network (e.g., WLAN), such as an 802.11x Wi-Fi network or an 802.15.4 network, and/or for a wide area network (e.g., WAN), such as a 3rd generation (e.g., 3G) cellular network, 4th generation (e.g., 4G) cellular network, or long term evolution (e.g., LTE) cellular network. The network interface(s)26may also include interfaces for, for example, broadband fixed wireless access networks (e.g., WiMAX), mobile broadband Wireless networks (e.g., mobile WiMAX), and so forth and/or an NFC communication interface. The network interface(s)26may also include antenna(s)27that detect and/or transmit wireless signals around the electronic device10and passes the received signals to/from transceiver/receiver(s)28. The transceiver/receiver(s)28may include one or more receivers and/or transmitters that are configured to send and/or receive information via one or more respective antennas of the antenna(s)27. Each transceiver/receiver28may be connected to its own antenna27. Alternatively, at least some of the transceiver/receiver(s)28may share an antenna27.

By way of example, the electronic device10may represent a block diagram of the notebook computer depicted inFIG. 2, the handheld device depicted in either ofFIG. 3orFIG. 4, the desktop computer depicted inFIG. 5, the wearable electronic device depicted inFIG. 6, or similar devices. It should be noted that the processor(s)12and/or other data processing circuitry may be generally referred to herein as “data processing circuitry.” Such data processing circuitry may be embodied wholly or in part as software, firmware, hardware, or any combination thereof. Furthermore, the data processing circuitry may be a single contained processing module or may be incorporated wholly or partially within any of the other elements within the electronic device10.

In certain embodiments, the electronic device10may take the form of a computer, a portable electronic device, a wearable electronic device, or other type of electronic device. Such computers may include computers that are generally portable (e.g., such as laptop, notebook, and tablet computers) as well as computers that are generally used in one place (e.g., such as conventional desktop computers, workstations and/or servers). In certain embodiments, the electronic device10in the form of a computer may be a model of a MacBook®, MacBook® Pro, MacBook Air®, iMac®, Mac® mini, or Mac Pro® available from Apple Inc. By way of example, the electronic device10, taking the form of a notebook computer30A, is illustrated inFIG. 2in accordance with one embodiment of the present disclosure. The depicted computer30A may include a housing or enclosure32, a display18, input structures20, and ports of the I/O interface22. In one embodiment, the input structures20(e.g., such as a built in keyboard and/or touchpad) may be used to interact with the computer30A, such as to start, control, or operate a graphical user interface (GUI) or applications running on computer30A. For example, a keyboard and/or touchpad may allow a user to navigate a user interface or application interface displayed on display18.

FIG. 3depicts a front view of a handheld device30B, which represents one embodiment of the electronic device10. The handheld device30B may represent, for example, a portable phone, a media player, a personal data organizer, a handheld game platform, or any combination of such devices. By way of example, the handheld device30B may be a model of an iPod® or iPhone® available from Apple Inc. of Cupertino, Calif.

The handheld device30B may include an enclosure32to protect interior components from physical damage and to shield them from electromagnetic interference. The enclosure32may surround the display18, which may display indicator icons34. The indicator icons34may indicate, among other things, a cellular signal strength, Bluetooth connection, and/or battery life. Likewise, the handheld device30B may include graphical icons36that may be part of a GUI, which allow a user to interact with the handheld device30B. Additionally, the illustrated I/O interface22may open through the enclosure32and may include, for example, an I/O port for a hard wired connection for charging and/or content manipulation using a connector and protocol, such as the Lightning connector provided by Apple Inc., a universal serial bus (e.g., USB), one or more conducted RF connectors, or other connectors and protocols.

User input structures20, in combination with the display18, may allow a user to control the handheld device30B. For example, one of the input structures20may activate or deactivate the handheld device30B, one of the input structures20may navigate user interface to a home screen, a user-configurable application screen, and/or activate a voice-recognition feature of the handheld device30B, while other of the input structures20may provide volume control, or may toggle between vibrate and ring modes. Additional input structures20may also include a microphone may obtain a user's voice for various voice-related features, and a speaker to allow for audio playback and/or certain phone capabilities. The input structures20may also include a headphone input (not illustrated) to provide a connection to external speakers and/or headphones and/or other output structures.

FIG. 4depicts a front view of another handheld device30C, which represents another embodiment of the electronic device10. The handheld device30C may represent, for example, a tablet computer, or one of various portable computing devices. By way of example, the handheld device30C may be a tablet-sized embodiment of the electronic device10, which may be, for example, a model of an iPad® available from Apple Inc. of Cupertino, Calif.

Turning toFIG. 5, a computer30D may represent another embodiment of the electronic device10ofFIG. 1. The computer30D may be any computer, such as a desktop computer, a server, or a notebook computer, but may also be a standalone media player or video gaming machine. By way of example, the computer30D may be an iMac®, a MacBook®, or other similar device by Apple Inc. It should be noted that the computer30D may also represent a personal computer (e.g., PC) by another manufacturer. A similar enclosure32may be provided to protect and enclose internal components of the computer30D such as the display18. In certain embodiments, a user of the computer30D may interact with the computer30D using various peripheral input devices as the input structures20, such as the keyboard38or mouse40, which may connect to the computer30D via an I/O interface22.

Similarly,FIG. 6depicts a wearable electronic device30E representing another embodiment of the electronic device10ofFIG. 1that may be configured to operate using the techniques described herein. By way of example, the wearable electronic device30E, which may include a wristband42, may be an Apple Watch® by Apple, Inc. However, in other embodiments, the wearable electronic device30E may include any wearable electronic device such as, for example, a wearable exercise monitoring device (e.g., pedometer, accelerometer, heart rate monitor), or other device by another manufacturer. The display18of the wearable electronic device30E may include a touch screen (e.g., LCD, an organic light emitting diode display (OLED), an active-matrix organic light emitting diode (AMOLED) display, and so forth), which may allow users to interact with a user interface of the wearable electronic device30E.

The embodiments ofFIGS. 2-6are examples of mobile and stationary electronic devices that may include one or more network interfaces26to transmit or receive signals wirelessly. Such wireless communication may use Long-Term Evolution (LIE), Wideband Code Division Multiple Access (WCDMA), Wi-Fi, wireless local area networks (WLAN), Bluetooth, Global Positioning System (GPS), Near-Field Communication (NFC), Radio Frequency Identification (RFID), and/or other suitable wireless communication protocols using one or more transceiver/receiver(s)28. Further details regarding embodiments of the network interface26are described below with respect toFIGS. 7 and 8.

FIG. 7depicts a general electronic device10utilizing a baseband integrated circuit (BBIC)44for signal and data processing and a radiohead46to transmit and receive wireless signals. The BBIC44, radiohead46, antenna(s)27, or a combination thereof may be included, in whole or in part, as part of the network interface26and may be utilized, for example, in RF communications. Additionally,FIGS. 7 and 8are for illustration purposes only, and it should be understood, that the placement of the antenna27may be a design parameter and that antenna27placement may be external to, affixed to, internal to, or coupled to the enclosure32of the electronic device.

In some embodiments, the BBIC44may include one or more processors coupled to one or more of memory and/or nonvolatile storage devices and may operate in conjunction with the memory and/or nonvolatile storage devices to perform various algorithms and/or data/signal processing. The radiohead46may include one or more transceiver/receiver(s)28, a RF frontend48, and/or a power management IC. The transceiver/receiver(s)28may receive one or more data and control signals and operate to generate a signal for transmission from the device or receive a communication signal and transmit the results to the BBIC44. The RF frontend48may operate to, for example, convert a signal into a format for transmission via the antenna(s)27and/or convert a signal received from the antenna(s)27into a format for transmission to the transceiver/receiver(s)28. The power management IC may be used to regulate and/or amplify the RF signals transmitted or received via the antenna(s)27and/or to supply current to the other radiohead46components (e.g., the transceiver/receiver(s)28, the RF frontend48).

The radiohead46may be capable of any of the above described suitable wireless communication protocols or a combination thereof. For example, if more than one radiohead46is used in a single electronic device10, each of the radioheads46may be the same (e.g., to generate and transmit signals on a common frequency band) or different (e.g., to generate and transmit signals on differing frequency bands). In some embodiments, transmission of a signal from the electronic device10may be based upon signals sent from the BBIC44via one or more routing lines to the transceiver/receiver28of the radiohead46. These routing lines may include designated or shared lines for control, data, clock, or other appropriate signals to the radiohead46. Control and clock signals may facilitate transmission and/or reception of wireless signals by the radiohead46(e.g., control the operation and timing of the radiohead46) while the data signals may include information to be transmitted from the electronic device10or received at the electronic device10. In a transmission mode, data may be transmitted from the transceiver/receiver28to the RF front end48, which may translate the signals (e.g., may apply digital to analog conversion of the data signals). Additionally, the data signals may be routed through the power management IC to amplify the data signals prior to their transmission. From the RF front end48and/or the power management IC, the data signals are carried along transmission lines50to the antenna(s)27and wirelessly transmitted therefrom. In a reception mode, the reverse process may occur.

For example, when the electronic device10is receiving communications, a signal may be received by the antenna(s)27and travel down transmission lines50to the radiohead46. The RF front end48in the radiohead46may convert the received (e.g., analog) signal to a digital signal and send the digital signal to the BBIC44via the transceiver/receiver28and routing lines. The BBIC44may further interpret the received data signal and/or pass the data onto additional circuitry of the electronic device10. As would be appreciated by one skilled in the art, the RF front end48and the power management IC may be incorporated as a single IC, as shown inFIG. 7, or may be physically separate components. Additionally, the transceiver/receiver28, RF front end48, and/or power management IC may all be combined in a single chip.

In general, routing lines between the BBIC44and the radiohead46may include of multiple metal wires (e.g., solid wire, stranded wire, ribbon cable, or other suitable metal medium), and, accordingly, may produce unwanted electromagnetic interference as signals are transmitted across the routing lines. The digital clock signal, for example, having a relatively fast and possibly constant frequency, represents a significant source of electromagnetic interference to other subsystems in the electronic device10when transmitted over a metal wire. Likewise, data lines of the routing lines may transmit a large volume of information relative to, for example, control lines of the routing lines and therefore, may also generate a significant source of electromagnetic interference. In an attempt to minimize this interference, the routing lines have been kept short by placing the radiohead46in close proximity to the BBIC44, but the metal routing lines still produce electromagnetic interference.

As depicted inFIG. 7, in one embodiment, to alleviate the electromagnetic interference caused by the use of metallic routing lines, fiber optic connections may be used in place of metal connections to create the routing lines. In general, fiber optic connections have much higher bandwidth than metal wires, and therefore a single fiber optic routing line52may replace multiple metal routing lines. Utilizing a fiber optic routing line52may also save space on a printed circuit board (PCB) by reducing the footprint associated with metallic routing lines. Additionally, the fiber optic routing line52may generate very little, if any, electromagnetic interference, as compared to the metal routing lines. Replacement of the metallic connections at the BBIC44and the radiohead46may also be undertaken.

For example, in some embodiments, optical interfaces may be utilized in place of metal inputs (e.g., pins, pads, and the like). These optical interfaces may be located on-chip and may include, for example, optical field programmable gate arrays (FPGAs), a diamond micro interface (DMI), or other suitable optical interfaces. Using such on-chip methods, the optical interfaces and/or controllers may be integrated directly onto the BBIC44and radiohead46(e.g., the transceiver/receiver(s)28) or may be coupled externally to the BBIC44and radiohead46.

Additionally, the fiber optic routing line52may be used alone or in conjunction with traditional metal routing lines. For example, the fiber optic routing line52may be used in conjunction with a single or two-wire control line54, whereby the fiber optic routing line52transmits data or data and clock signals. In this embodiment, the control line54carries control signals instead of data signals to minimize traffic, and thus minimize electromagnetic interference, while the fiber optic routing line52carries data signals between the BBIC44and the radiohead46. In another embodiment, a multimode optical fiber (e.g., multimode plastic optical fiber (POF)) may be utilized to allow separate modes for data and control signal transmission, which may allow for the removal of the control line54.

By employing a fiber optic routing line52, electromagnetic interference to and from other circuitry within the electronic device10(e.g., processor12, memory14, storage16, etc.) may be reduced. Additionally, the use of a fiber optic routing line52may allow the repositioning of the radiohead46. Generally, the radiohead46is located in close proximity to the BBIC44to reduce the electromagnetic interference associated with the traditional metal routing lines by shortening (e.g., reducing) the physical length of the metal routing lines. By utilizing a fiber optic routing line52, the radiohead46may be relocated to a position in close proximity to the antenna27. This may provide an advantage of signals transmitted from the RF front end48having a shorter path to their respective antenna27prior to transmission, thus decreasing degradation of the RF front end48generated signal prior to its transmission.

FIG. 8illustrates an electronic device10with radioheads46located millimeters (mm), as opposed to centimeters (cm), from the antennas27. In one embodiment, the radiohead46may be located proximate to the outer edge of the enclosure32, such that the transmission lines50from the radiohead(s)46to the antenna(s)27are less than or equal to approximately 25 mm, 10 mm, or 5 mm in length. The close proximity of the radioheads46and the antennas27allows for significantly shortened transmission lines50. Shorter transmission lines50may lead to performance efficiency improvements such as decreased current drain and increased reception sensitivity as well as decreased cost associated with long RF cables (e.g., coax). Additionally, the shorter transmission lines50may have a lower susceptibility to electromagnetic interference from other circuitry56, and, in turn, produce less electromagnetic interference to affect other circuitry of the electronic device10.

In order to maintain two antennas27on opposing sides of the enclosure32, while also keeping the transmission lines50relatively short, the embodiment ofFIG. 8includes two radioheads46. However, it should be understood that additional antennas27may be employed and arranged at different positions about the enclosure32, each with their own respective radiohead46. Each of the illustrated radioheads46may be connected to the BBIC44via separate fiber optic routing lines52or may utilize a common fiber optic routing line52, thus requiring just one optical controller on the BBIC44. In some embodiments, if a common fiber optic routing line52is utilized, a fiber optic splitter or junction may be employed either at the BBIC44, a radiohead46, or elsewhere in the electronic device10. As stated above, the radioheads46may be of the same variety, or geared toward different frequency bands and/or communication protocols.

The use of multiple radioheads46, either using a common fiber optic routing line52or separate fiber optic routing lines52, may be controlled by one or more control lines54connected to the BBIC44. In both cases, the control lines54may carry control signals, that may, for example, indicate which radiohead46is to transmit/receive which RF signals. Other control signals may be transmitted to synchronize data transmission/reception between multiple radioheads46and/or transmit/receive different RF signals on the separate radioheads46simultaneously. Furthermore, as shown inFIG. 8, the control lines54to each of the radioheads46may be grouped together as a control bus. Additionally, as stated above, a multimode fiber optic (e.g., a plastic optical fiber (POF)) may be employed to transfer both data and control signals without the use of traditional metal routing lines or any separate control line54.

The radiohead(s)46may be physically closer to the antenna(s)27than the BBIC44and/or may be positioned such that at least one of the transmission lines50is shorter than the respective fiber optic routing line52. In some embodiments, the radiohead(s)46may be located at a position that is approximately, for example, 75%, 85%, or 95% of the total distance from the BBIC44to the antenna(s)27. Furthermore, the radiohead(s)46may be located within approximately, for example, 0.1 in, 0.5 in, 1 in, 2 in, or 5 in of their respective antenna(s). As explained above, employing one or more radioheads46in such locations, shortening the transmission lines50, and utilizing fiber optic routing lines52may help increase transmission and/or reception performance, decrease current draw, and reduce the electromagnetic interference to and from other circuitry56within or in close proximity to the electronic device10.