Patent Application
20140225805
The present disclosure relates to phased array antennas, and more particularly, to conformal phased array antennas with integrated transceivers.
Electronic devices, such as laptops, notebooks, netbooks, personal digital assistants (PDAs) and mobile phones, for example, increasingly tend to include a variety of wireless communication capabilities. The wireless communication systems used by these devices are expanding into the higher frequency ranges of the communication spectrum, such as, for example, the millimeter wave region and, in particular, the 60 GHz band. Propagation losses and attenuation tend to increase at these higher frequencies, however, and it can become difficult to implement antenna systems on the device platform in a manner that provides the desired spatial coverage, for example, omni-directional or nearly omni-directional coverage.
Existing approaches to solve this problem generally rely on the deployment of multiple active antenna modules on various sides of the device to increase spatial coverage. This approach, however, increases cost and power consumption and becomes increasingly impractical as platform sizes shrink or take on unusual form factors with a variety of surface contours and angles.
Features and advantages of embodiments of the claimed subject matter will become apparent as the following Detailed Description proceeds, and upon reference to the Drawings, wherein like numerals depict like parts, and in which:
Although the following Detailed Description will proceed with reference being made to illustrative embodiments, many alternatives, modifications, and variations thereof will be apparent to those skilled in the art.
Generally, this disclosure provides systems and methods for achieving increased spatial coverage of wireless communications by deploying conformal phased array antennas, with integrated transceivers, on a platform. The antenna elements may be disposed on a flexible substrate capable of conforming to the contours of the platform, allowing the antenna elements to be deployed at suitable locations on the platform, for example the sides and top of the platform, to achieve multi-directional radio frequency (RF) spatial coverage. Additionally, some or all of the antenna elements may be coupled to integrated transceivers with phase shifting capabilities that enable those antenna elements to form a phased array antenna (also referred to as an active antenna). The phased array antenna may perform beam scanning to further increase RF spatial coverage. In some embodiments, the transceivers and any additional RF circuitry may be included in a single RF integrated circuit (RFIC) and the RFIC may be integrated with the conformal phased array antennas to decrease power and space consumption. The system may be configured to operate in the millimeter wave (mm-wave) region of the RF spectrum and, in particular, the 60 GHz region associated with the use of wireless personal area network (WPAN) and wireless local area network (WLAN) communication systems.
The term Personal basic service set Control Point (PCP) as used herein, is defined as a station (STA) that operates as a control point of the mm-wave network.
The term access point (AP) as used herein, is defined as any entity that has STA functionality and provides access to the distribution services, via the wireless medium (WM) for associated STAs.
The term wireless network controller as used herein, is defined as a station that operates as a PCP and/or as an AP of the wireless network.
The term directional band (DBand) as used herein is defined as any frequency band wherein the Channel starting frequency is above 45 GHz.
The term DBand STA as used herein is defined as a STA whose radio transmitter is operating on a channel that is within the DBand.
The term personal basic service set (PBSS) as used herein is defined as a basic service set (BSS) which forms an ad hoc self-contained network, operates in the DBand, includes one PBSS control point (PCP), and in which access to a distribution system (DS) is not present but an intra-PBSS forwarding service is optionally present.
The term scheduled service period (SP) as used herein is scheduled by a quality of service (QoS) AP or a PCP. Scheduled SPs may start at fixed intervals of time, if desired.
The terms “traffic” and/or “traffic stream(s)” as used herein, are defined as a data flow and/or stream between wireless devices such as STAs. The term “session” as used herein is defined as state information kept or stored in a pair of stations that have an established a direct physical link (e.g., excludes forwarding); the state information may describe or define the session.
The term “wireless device” as used herein includes, for example, a device capable of wireless communication, a communication device capable of wireless communication, a communication station capable of wireless communication, a portable or non-portable device capable of wireless communication, or the like. In some embodiments, a wireless device may be or may include a peripheral device that is integrated with a computer, or a peripheral device that is attached to a computer. In some embodiments, the term “wireless device” may optionally include a wireless service.
It should be understood that the present invention may be used in a variety of applications. Although the present invention is not limited in this respect, the circuits and techniques disclosed herein may be used in many apparatuses such as stations of a radio system. Stations intended to be included within the scope of the present invention include, by way of example only, WLAN stations, wireless personal network (WPAN), and the like.
Types of WPAN stations intended to be within the scope of the present invention include, although are not limited to, stations capable of operating as a multi-band stations, stations capable of operating as PCP, stations capable of operating as an AP, stations capable of operating as DBand stations, mobile stations, access points, stations for receiving and transmitting spread spectrum signals such as, for example, Frequency Hopping Spread Spectrum (FHSS), Direct Sequence Spread Spectrum (DSSS), Complementary Code Keying (CCK), Orthogonal Frequency-Division Multiplexing (OFDM) and the like.
Some embodiments may be used in conjunction with various devices and systems, for example, a video device, an audio device, an audio-video (A/V) device, a Set-Top-Box (STB), a Blu-ray disc (BD) player, a BD recorder, a Digital Video Disc (DVD) player, a High Definition (HD) DVD player, a DVD recorder, a HD DVD recorder, a Personal Video Recorder (PVR), a broadcast HD receiver, a video source, an audio source, a video sink, an audio sink, a stereo tuner, a broadcast radio receiver, a display, a flat panel display, a Personal Media Player (PMP), a digital video camera (DVC), a digital audio player, a speaker, an audio receiver, an audio amplifier, a data source, a data sink, a Digital Still camera (DSC), a Personal Computer (PC), a desktop computer, a mobile computer, a laptop computer, a notebook computer, a tablet computer, a server computer, a handheld computer, a handheld device, a Personal Digital Assistant (PDA) device, a handheld PDA device, an on-board device, an off-board device, a hybrid device, a vehicular device, a non-vehicular device, a mobile or portable device, a consumer device, a non-mobile or non-portable device, a wireless communication station, a wireless communication device, a wireless AP, a wired or wireless router, a wired or wireless modem, a wired or wireless network, a wireless area network, a Wireless Video Are Network (WVAN), a Local Area Network (LAN), a WLAN, a PAN, a WPAN, devices and/or networks operating in accordance with existing WirelessHD™ and/or Wireless-Gigabit-Alliance (WGA) specifications and/or future versions and/or derivatives thereof, devices and/or networks operating in accordance with existing IEEE 802.11 (IEEE 802.11-2007: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications) standards and amendments (“the IEEE 802.11 standards”), IEEE 802.16 standards, and/or future versions and/or derivatives thereof, units and/or devices which are part of the above networks, one way and/or two-way radio communication systems, cellular radio-telephone communication systems, Wireless-Display (WiDi) device, a cellular telephone, a wireless telephone, a Personal Communication Systems (PCS) device, a PDA device which incorporates a wireless communication device, a mobile or portable Global Positioning System (GPS) device, a device which incorporates a GPS receiver or transceiver or chip, a device which incorporates an RFID element or chip, a Multiple Input Multiple Output (MIMO) transceiver or device, a Single Input Multiple Output (SIMO) transceiver or device, a Multiple Input Single Output (MISO) transceiver or device, a device having one or more internal antennas and/or external antennas, Digital Video Broadcast (DVB) devices or systems, multi-standard radio devices or systems, a wired or wireless handheld device (e.g., BlackBerry, Palm Treo), a Wireless Application Protocol (WAP) device, or the like.
Some embodiments may be used in conjunction with one or more types of wireless communication signals and/or systems, for example, Radio Frequency (RF), Infra Red (IR), Frequency-Division Multiplexing (FDM), Orthogonal FDM (OFDM), Time-Division Multiplexing (TDM), Time-Division Multiple Access (TDMA), Extended TDMA (E-TDMA), General Packet Radio Service (GPRS), extended GPRS, Code-Division Multiple Access (CDMA), Wideband CDMA (WCDMA), CDMA 2000, single-carrier CDMA, multi-carrier CDMA, Multi-Carrier Modulation (MDM), Discrete Multi-Tone (DMT), Bluetooth®, Global Positioning System (GPS), Wi-Fi, Wi-Max, ZigBee™, Ultra-Wideband (UWB), Global System for Mobile communication (GSM), 2 G, 2.5 G, 3 G, 3.5 G, Enhanced Data rates for GSM Evolution (EDGE), or the like. Other embodiments may be used in various other devices, systems and/or networks.
Some embodiments may be used in conjunction with suitable limited-range or short-range wireless communication networks, for example, “piconets”, e.g., a wireless area network, a WVAN, a WPAN, and the like.
In a preferred embodiment, a single RFIC 104 may drive all conformal antennas 106, 108 and 110 as will be explained in greater detail below. The use of a single RFIC 104 may permit reduction in cost, power consumption and space consumption. The RFIC may be implemented in silicon complementary metal-oxide semiconductor (Si CMOS) technology or other suitable technologies.
Conformal antennas 106, 108 and 110 may comprise antenna elements that are printed onto a substrate that has sufficient flexibility for the conformal antenna to conform to the contours of the platform 102. The substrate may be a single layer or multiple layers, which, in some embodiments, may be configured as a laminate structure. The layers may comprise a dielectric material with a low tangent loss, i.e., configured to reduce dissipation of electromagnetic energy associated with mm-wave RF signal propagation and thus increase antenna performance. Examples of suitable materials for the layers include, but are not limited to, liquid crystal polymer (LCP) such as Ultralam 3000®, polyimide and Teflon.
Beam patterns 208a, 208b, 208c may be generated by beam scanning of phased array antenna elements in conformal antenna 108 as will be explained in greater detail below. The scanned beams 208a, 208b, 208c may be directed to cover a spatial area over the top of the platform 102. Although only 3 beams 208a, 208b, 208c are shown for illustrative purposes, in practice, the phased array antenna may generate a beam that is scanned or steered through many more positions by incrementally adjusting the relative phases of the antenna elements to repeatedly sweep the beam through an arc of desired coverage.
Additional beams, not shown, may also be directed outward in other directions as needed. For example, antenna elements may be located on either or both sides of the ninety degree bends in the conformal antennas 106, 108, 110 to provide beams in substantially orthogonal directions. These example antenna configurations and beam patterns are provided for illustrative purposes. In practice, however, any suitable arrangement may be implemented.
In some embodiments, the antenna elements that are configured in a phased array 306, 314 may comprise dummy antenna elements 318 at some or all of the edges of the phased array. The edge antenna elements 318 may generally be located at the end of the transmission line that couples the RFIC 104 to the antenna elements 306, 314. The dummy antenna elements 318 may be termination load resistors that reduce reflections of the RF signal at the end of the transmission line by providing termination impedance that is matched to the characteristic impedance of the transmission line. This may increase the stability of the frequency and bandwidth properties of the phased array as it scans the beam through different angles.
Signal routing layer 414 includes electrical traces or transmission lines (not shown) coupling RFIC 104 to each of the antenna elements 314, 304, 306 disposed on the flexible substrate 412. Since phased array beam scanning is based, in part, on the difference in reception times (or transmission times) of the RF signal at each of the phased array antenna elements 314, 306, it may be advantageous to reduce other sources of timing differences between signals at each of the those antenna elements 314, 306. In some embodiments, therefore, the electrical traces may be routed through the signal routing layer 414 in a variety of meandering patterns to achieve an equalized trace length, and thus an equalized signal delay time, between the RFIC 104 and each of the phased array antenna elements 314, 306. The term “equalized” as used herein, means that the difference in lengths between each of the traces is reduced to a sufficiently small value such that a desired level of beam scanning performance may be achieved. This is illustrated in
Alternatively, the electrical traces may be routed through the signal routing layer 414 in a manner that results in known timing differences between the RFIC 104 and each of the phased array antenna elements 314, 306, such that corrections for those known timing differences may be applied in subsequent processing stages to compensate for those differences.
Returning now to
The RFIC 104 may be a bidirectional circuit, configured to both transmit and receive. In the transmit direction, an IF signal 604 may be provided to RFIC 104 from BBIC 402. An RF carrier is generated by RF carrier generator 608 and mixed with IF signal 604 by mixer 606 to up-convert the IF signal 604 to an RF signal. Mixer 606 may be a passive bi-directional mixer. The RF signal may be amplified by bi-directional amplifier 610 and then coupled to one or more single element antennas 304 (only one shown) and/or one or more phased array antenna systems 622 (only one shown). The single element antenna 304 transmits the RF signal in a fixed beam pattern. The phased array antenna system 622 transmits the RF signal in a scanned beam pattern, the direction of which is adjustable. To accomplish this, the RF signal is split by splitter/summer 614 and fed to a plurality of transceivers 616. Each transceiver 616 is configured with a phase shifter 618 capable of independently adjusting the phase of the split RF signal being fed to that transceiver 616. The phase shifted RF signal is further amplified by power amplifier (PA) 620 and fed to the antenna element 314 associated with the transceiver 616.
The phase shifter 618 may be under the control of phased array controller 624, which controls the amount and timing of the phase shift adjustments for each transceiver 616. By independently adjusting the phase of each of the split RF signals transmitted through each antenna element 314, a pattern of constructive and destructive interference may be generated between the antenna elements 314 that results in a beam pattern of a desired shape that can be steered to a particular direction. By varying the phase adjustments in real-time, the resultant transmit beam pattern can be scanned through a desired range of directions. In some embodiments the phased array controller 624 may be a general purpose processor, a digital signal processor (DSP), programmable logic or firmware.
A similar process may operate in the receive direction. Each antenna element 314 receives an RF signal which is processed by associated transceiver 616, where it is amplified by low noise amplifier (LNA) 620 and phase shifted by phase shifter 618 under control of phased array controller 624. The outputs of each transceiver 616 are summed by splitter/summer 614. Received RF signals arriving from different directions generally reach each of antenna elements 314 at different times. Phase shifting, which is equivalent to time shifting, may be employed to time align the received RF signals arriving from a particular direction while leaving received RF signals arriving from other directions unaligned. The summation of these RF signals by splitter/summer 614 results in a gain for the time aligned components associated with signals arriving from that particular direction. This results in a beam pattern gain in that direction. By varying the phase adjustments in real-time, the resultant receive beam pattern can be scanned through a desired range of directions.
The received RF signal, from either phased array antenna system 622 or single element antenna 304, may be further amplified by bi-directional amplifier 610 and then mixed by mixer 606 with the RF carrier generated by RF carrier generator 608 to down-convert the RF signal to an output IF signal 604 which is sent to BBIC 402 for baseband processing.
In some embodiments, the system is configured to operate on RF signals in the frequency range from 57-60 GHz and IF signals in the frequency range from 11.4-13.2 GHz. Baseband signals may be in the approximate range of 2 GHz.
Embodiments of the methods described herein may be implemented in a system that includes one or more storage mediums having stored thereon, individually or in combination, instructions that when executed by one or more processors perform the methods. Here, the processor may include, for example, a system CPU (e.g., core processor) and/or programmable circuitry. Thus, it is intended that operations according to the methods described herein may be distributed across a plurality of physical devices, such as processing structures at several different physical locations. Also, it is intended that the method operations may be performed individually or in a subcombination, as would be understood by one skilled in the art. Thus, not all of the operations of each of the flow charts need to be performed, and the present disclosure expressly intends that all subcombinations of such operations are enabled as would be understood by one of ordinary skill in the art.
The storage medium may include any type of tangible medium, for example, any type of disk including floppy disks, optical disks, compact disk read-only memories (CD-ROMs), compact disk rewritables (CD-RWs), digital versatile disks (DVDs) and magneto-optical disks, semiconductor devices such as read-only memories (ROMs), random access memories (RAMs) such as dynamic and static RAMs, erasable programmable read-only memories (EPROMs), electrically erasable programmable read-only memories (EEPROMs), flash memories, magnetic or optical cards, or any type of media suitable for storing electronic instructions.
“Circuitry”, as used in any embodiment herein, may comprise, for example, singly or in any combination, hardwired circuitry, programmable circuitry, state machine circuitry, and/or firmware that stores instructions executed by programmable circuitry.
The terms and expressions which have been employed herein are used as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described (or portions thereof), and it is recognized that various modifications are possible within the scope of the claims. Accordingly, the claims are intended to cover all such equivalents. Various features, aspects, and embodiments have been described herein. The features, aspects, and embodiments are susceptible to combination with one another as well as to variation and modification, as will be understood by those having skill in the art. The present disclosure should, therefore, be considered to encompass such combinations, variations, and modifications.
| Number | Date | Country | Kind |
|---|---|---|---|
| 61452754 | Mar 2011 | US | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US11/54491 | 10/1/2011 | WO | 00 | 11/15/2013 |
