Abstract:
Multiple-antenna configurations with at least one embedded antenna. At least one cable in a group of antenna cables functions as an embedded antenna by being configured with some or all of a second of coaxial cable shielding being removed. Multiple embedded antennae may be provided in a multiple-antenna configuration.

Description:
TECHNICAL FIELD 
       [0001]    Embodiments of the invention relate to multi-antenna configurations. More particularly, embodiments of the invention relate to multi-antenna devices in which one or more of the antennae are antennae embedded within cable within the device. 
       BACKGROUND 
       [0002]    Electronic devices such as computer systems and personal digital assistants (PDAs) commonly support wireless communication functionality. The wireless functionality may support multiple wireless protocols and/or multi-antenna, multiple input/multiple output (MIMO) protocols. As the number of antennae required increases the packaging and/or management of these antennae may become more complicated. 
         [0003]    For example, a computer system may have an antenna array for use in MIMO communications that may include three or more antennae. In order to provide satisfactory performance in terms of isolation and/or other parameters, the individual antennae may be spaced a significant distance apart. This may result in an antenna array enclosure that is relatively large, which may result in reduced user satisfaction. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]    Embodiments of the invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like reference numerals refer to similar elements. 
           [0005]      FIG. 1  is a block diagram of one embodiment of an electronic system. 
           [0006]      FIG. 2  is an illustration of one embodiment of a multi-antenna array having one embedded antenna. 
           [0007]      FIG. 3  is an illustration of one embodiment of a multi-antenna array having two embedded antennae. 
           [0008]      FIG. 4  is an illustration of one embodiment of a multi-antenna array having three embedded antennae. 
           [0009]      FIG. 5  illustrates one embodiment of an embedded antenna. 
           [0010]      FIG. 6  illustrates one embodiment of an embedded slot antenna. 
           [0011]      FIG. 7  illustrates one embodiment of an embedded planar inverted F antenna (PIFA). 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    In the following description, numerous specific details are set forth. However, embodiments of the invention may be practiced without these specific details. In other instances, well-known circuits, structures and techniques have not been shown in detail in order not to obscure the understanding of this description. 
         [0013]      FIG. 1  is a block diagram of one embodiment of an electronic system. The electronic system illustrated in  FIG. 1  is intended to represent a range of electronic systems (either wired or wireless) including, for example, desktop computer systems, laptop computer systems, cellular telephones, personal digital assistants (PDAs) including cellular-enabled PDAs, set top boxes. Alternative electronic systems may include more, fewer and/or different components. 
         [0014]    Electronic system  100  includes bus  105  or other communication device to communicate information, and processor  110  coupled to bus  105  that may process information. While electronic system  100  is illustrated with a single processor, electronic system  100  may include multiple processors and/or co-processors. Electronic system  100  further may include random access memory (RAM) or other dynamic storage device  120  (referred to as main memory), coupled to bus  105  and may store information and instructions that may be executed by processor  110 . Main memory  120  may also be used to store temporary variables or other intermediate information during execution of instructions by processor  110 . 
         [0015]    Electronic system  100  may also include read only memory (ROM) and/or other static storage device  130  coupled to bus  105  that may store static information and instructions for processor  110 . Data storage device  140  may be coupled to bus  105  to store information and instructions. Data storage device  140  such as a magnetic disk or optical disc and corresponding drive may be coupled to electronic system  100 . 
         [0016]    Electronic system  100  may also be coupled via bus  105  to display device  150 , such as a cathode ray tube (CRT) or liquid crystal display (LCD), to display information to a user. Alphanumeric input device  160 , including alphanumeric and other keys, may be coupled to bus  105  to communicate information and command selections to processor  110 . Another type of user input device is cursor control  170 , such as a mouse, a trackball, or cursor direction keys to communicate direction information and command selections to processor  110  and to control cursor movement on display  150 . 
         [0017]    Electronic system  100  further may include network interface(s)  180  to provide access to a network, such as a local area network. Network interface(s)  180  may include, for example, a wireless network interface having antenna  185 , which may represent one or more antenna(e). Network interface(s)  180  may also include, for example, a wired network interface to communicate with remote devices via network cable  187 , which may be, for example, an Ethernet cable, a coaxial cable, a fiber optic cable, a serial cable, or a parallel cable. 
         [0018]    In one embodiment, network interface(s)  180  may provide access to a local area network by conforming to IEEE 802.16 standards. IEEE 802.16 corresponds to IEEE 802.15-2005 entitled “Air Interface for Fixed Broadband Wireless Access Systems” approved Dec. 7, 2005 as well as related documents. 
         [0019]    In one embodiment, network interface(s)  180  may provide access to a local area network, for example, by conforming to IEEE 802.11b and/or IEEE 802.11g standards, and/or the wireless network interface may provide access to a personal area network, for example, by conforming to Bluetooth standards. Other wireless network interfaces and/or protocols can also be supported. 
         [0020]    IEEE 802.11b corresponds to IEEE Std. 802.11b-1999 entitled “Local and Metropolitan Area Networks, Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications: Higher-Speed Physical Layer Extension in the 2.4 GHz Band,” approved Sep. 16, 1999 as well as related documents. IEEE 802.11g corresponds to IEEE Std. 802.11g-2003 entitled “Local and Metropolitan Area Networks, Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications, Amendment  4 : Further Higher Rate Extension in the 2.4 GHz Band,” approved Jun. 27, 2003 as well as related documents. Bluetooth protocols are described in “Specification of the Bluetooth System: Core, Version 1.1,” published Feb. 22, 2001 by the Bluetooth Special Interest Group, Inc. Associated as well as previous or subsequent versions of the Bluetooth standard may also be supported. 
         [0021]    In addition to, or instead of, communication via wireless LAN standards, network interface(s)  180  may provide wireless communications using, for example, Time Division, Multiple Access (TDMA) protocols, Global System for Mobile Communications (GSM) protocols, Code Division, Multiple Access (CDMA) protocols, and/or any other type of wireless communications protocol. 
         [0022]      FIG. 2  is an illustration of one embodiment of a multi-antenna array having one embedded antenna. In one embodiment the multi-antenna array may be used to support IEEE 802.16 compliant communications, which included MIMO-based communications techniques. Other antenna types, for example, Bluetooth and/or WLAN antennae may also be included in the multi-antenna array. 
         [0023]    The multi-antenna array may include multi-antenna connector  200  that provides a physical interface to a host system. Multi-antenna connector  200  may be any type of interface that allows a host system to send and receive wireless signals. In one embodiment, the multi-antenna array may include three or more cables (e.g.,  220 ,  230 ,  240 ) that may carry signals between multi-antenna connector  200  and the respective antennae (e.g.,  225 ,  235 ,  245 ). Multi-antenna connector  200  may be, for example, an RJ-type connector, a USB connector, etc. 
         [0024]    In one embodiment, two cables ( 220  and  230 ) may be coupled between multi-antenna connector  200  and individual antennas ( 225  and  235 , respectively) in a multi-antenna array. Cable  220  may be any appropriate type of electrical connection between multi-antenna connector  200  and antenna  225 . Similarly, cable  230  may be any appropriate type of electrical connection between multi-antenna connector  200  and antenna  235 . 
         [0025]    Cable  240  may be a coaxial cable configured to include embedded antenna  245 . Example embodiments of an embedded antenna are described in greater detail below. In general, an embedded antenna is an antenna structure that part of a cable. 
         [0026]    In order to provide sufficient isolation (e.g., −30 db, −25 db, −27 db) and pattern coverage with three antennae, physical separation between the three or more antenna may be desirable. The separation required to achieve the desired isolation may be dependent on, for example, frequency range used, power levels, etc. In one embodiment, antenna  225  may be physically separated form antenna  235  by some distance (e.g., 6 inches, 8 inches, 4 inches) to provide sufficient isolation. 
         [0027]    In one embodiment, antenna  225 , antenna  235  and possibly additional antennae (not illustrated in  FIG. 2 ) may be housed in a single package that may be coupled to a host electronic system via cables  220  and  230 . In one embodiment, one or more of cables  220 ,  230  and  240  may be grouped together in a “ganged cable” arrangement. In one embodiment, antenna  225  and antenna  235  may have different polarities. For example, antenna  225  may have a horizontal polarity while antenna  235  may have a vertical polarity. 
         [0028]    The physical configuration of embedded antenna  245  in cable  240  may be selected to provide sufficient isolation. For example, embedded antenna  245  may be physically separated from antenna  225  and/or antenna  235 . Embedded antenna  245  may be several inches (e.g., 4 inches, 6 inches, 8 inches) from antenna  225  and antenna  235 . The separation between embedded antenna  245  and antenna  225  or antenna  235  may be selected based on, for example, the frequency range of signals transmitted and/or received, power levels, etc. 
         [0029]      FIG. 3  is an illustration of one embodiment of a multi-antenna array having two embedded antennae. In one embodiment the multi-antenna array may be used to support IEEE 802.16 compliant communications, which included MIMO-based communications techniques. Other antenna types, for example, Bluetooth and/or WLAN antennae may also be included in the multi-antenna array. 
         [0030]    The multi-antenna array may include multi-antenna connector  200  as described above. In one embodiment, the multi-antenna array may include three or more cables (e.g.,  320 ,  230 ,  240 ) that may carry signals between multi-antenna connector  200  and the respective antennae (e.g.,  325 ,  235 ,  245 ). 
         [0031]    Cable  320  may be a coaxial cable configured to include embedded antenna  325 . Cable  230  may be any appropriate type of electrical connection between multi-antenna connector  200  and antenna  235 . Cable  240  may be a coaxial cable configured to include embedded antenna  245 . Example embodiments of an embedded antenna are described in greater detail below. 
         [0032]    In one embodiment, antenna  235  and possibly additional antennae (not illustrated in  FIG. 4 ) may be housed in a single package that may be coupled to a host electronic system via cable  230 . In one embodiment, one or more of cables  320 ,  230  and  240  may be grouped together in a ganged cable arrangement. The physical configuration of embedded antenna  245  in cable  240  and embedded antenna  325  in cable  320  may be selected to provide desired isolation. For example, embedded antenna  245  may be physically separated from antenna  235 . Similarly, embedded antenna  325  may be physically separated form antenna  235  and embedded antenna  245 . Embedded antenna  325  may be several inches (e.g., 4 inches, 6 inches, 8 inches) from antenna  235  and embedded antenna  245 . The separation between embedded antenna  325  and embedded antenna  245  and/or antenna  235  may be selected based on, for example, the frequency range of signals transmitted and/or received, power levels, etc. 
         [0033]      FIG. 4  is an illustration of one embodiment of a multi-antenna array having three embedded antennae. In one embodiment the multi-antenna array may be used to support IEEE 802.16 compliant communications, which included MIMO-based communications techniques. Other antenna types, for example, Bluetooth and/or WLAN antennae may also be included in the multi-antenna array. 
         [0034]    The multi-antenna array may include multi-antenna connector  200  as described above. In one embodiment, the multi-antenna array may include three or more cables (e.g.,  320 ,  430 ,  240 ) that may carry signals between multi-antenna connector  200  and the respective antennae (e.g.,  325 ,  435 ,  245 ). 
         [0035]    Cable  430  may be a coaxial cable configured to include embedded antenna  435 . Cables  240  and  320  may be coaxial cables configured to include embedded antennae  245  and  325  as described above. Example embodiments of an embedded antenna are described in greater detail below. 
         [0036]    In one embodiment, one or more of cables  320 ,  430  and  240  may be grouped together in a ganged cable arrangement. The physical configuration of embedded antenna  435 , embedded antenna  245  in cable  240  and embedded antenna  325  in cable  320  may be selected to provide desired isolation. For example, embedded antenna  245  may be physically separated from embedded antenna  435 . Similarly, embedded antenna  325  may be physically separated form embedded antenna  435  and embedded antenna  245 . Each embedded antenna may be several inches (e.g., 4 inches, 6 inches, 8 inches) from other antennae. The separation between embedded antenna  435  and embedded antenna  245  and/or embedded antenna  325  may be selected based on, for example, the frequency range of signals transmitted and/or received, power levels, etc. 
         [0037]      FIG. 5  illustrates one embodiment of an embedded antenna. One or more of the embedded antennae described above may be implemented as the embedded antenna of  FIG. 5 . Coaxial cable  500  includes conductor  520 , which may be copper wire or other suitable conductive material, surrounded by insulating material  525 . Any appropriate insulating material known in the art may be used. 
         [0038]    Insulating material  525  may be surrounded by conductive layer  510  that may be, for example, a copper mesh or other suitable conductive material. In one embodiment, conductive layer  510  may include additional material  515  that may be used to tune the embedded antenna. Conductive layer  510  may be surrounded by outer insulation material  550 . Any material known in the art suitable for insulation and/or protection of the structure of coaxial cable  500  may be used for outer insulation material  550 . 
         [0039]    An embedded antenna may be created by removing insulating material  525 , conductive layer  510  and/or outer insulation material  550  to expose a portion of conductor  520 . The size of the exposed portion of conductor  520  may be determined based, at least in part, on the frequency used for wireless communications. In one embodiment, communications are in the 2.4 GHz and/or 5 GHz range; however, any frequency range can be supported with an embedded antennae. In one embodiment, current may be oscillated between conductor  520  and conductive layer  510  to cause the embedded antenna structure to function as an antenna. In various embodiments, the insulating, non-conductive portion of the cable may be retained for strength, shape and/or flexibility concerns. 
         [0040]    In alternate embodiments, one or more portions of multiple coaxial cables may be used to change the mode of the embedded antenna. For example, the structure of  FIG. 5  may be juxtaposed with another coaxial cable having a conductive layer that may be incorporated into the antenna design of the embedded antenna. Other alternative configurations may also be used. 
         [0041]      FIG. 6  illustrates one embodiment of an embedded slot antenna. One or more of the embedded antennae described above may be implemented as the embedded antenna of  FIG. 6 . Coaxial cable  600  includes conductor  620 , which may copper wire or other suitable conductive material, surrounded by insulating material  625 . Any appropriate insulating material known in the art may be used. 
         [0042]    Insulating material  625  may be surrounded by conductive layer  610  that may be, for example, a copper mesh or other suitable conductive material. Conductive layer  610  may be surrounded by outer insulation material  650 . Any material known in the art suitable for insulation and/or protection of the structure of coaxial cable  600  may be used for outer insulation material  650 . 
         [0043]    An embedded antenna may be created by removing insulating material  625 , conductive layer  610  and only a portion of outer insulation material  650  to create an aperture or slot to expose a portion of conductor  620 . This may result in a “slot” embedded antenna. The size of the aperture or exposed portion of conductor  620  may be determined based, at least in part, on the frequency used for wireless communications. In one embodiment, communications are in the 2.4 GHz and/or 5 GHz range; however, any frequency range can be supported with an embedded slot antennae. In one embodiment, current may be oscillated between conductor  620  and conductive layer  610  to cause the embedded antenna structure to function as an antenna. 
         [0044]    In alternate embodiments, one or more portions of multiple coaxial cables may be used to change the mode of the embedded antenna. For example, the structure of  FIG. 6  may be juxtaposed with another coaxial cable having a conductive layer that may be incorporated into the antenna design of the embedded antenna. Other alternative configurations may also be used. 
         [0045]      FIG. 7  illustrates one embodiment of an embedded planar inverted F antenna (PIFA). One or more of the embedded antennae described above may be implemented as the embedded antenna of  FIG. 7 . In one embodiment, at least three coaxial cables,  710 ,  720  and  730  are bundled within a single sheath  700 . Conductor  740  of coaxial cable  730  may function as a PIFA radiating element and the internal conductive layers of coaxial cables  710  and  720  may function as shield/ground planes that may allow the exposed portion of conductor  740  to function as a PIFA radiating element. Additional conductive material may be added, for example, as a sleeve that can be used to tune the PIFA antenna structure. 
         [0046]    Another type of embedded cable antenna may include multiple radiating elements with assigned frequencies of operation along the length of a single coaxial cable of bundle of coaxial cable or other impedance controlled cable. The position of the radiating elements corresponding to higher frequencies may be injected into the cable to reduce the cable loss at higher frequencies. The positioning of the radiating elements may be arranged to provide the desired isolation between elements or away from the driving components, which may be a source of interference. 
         [0047]    Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment. 
         [0048]    While the invention has been described in terms of several embodiments, those skilled in the art will recognize that the invention is not limited to the embodiments described, but can be practiced with modification and alteration within the spirit and scope of the appended claims. The description is thus to be regarded as illustrative instead of limiting.