Abstract:
A re-configurable RF architecture includes both a 2×2 MIMO mode and a 1×2 MIMO mode. The 2×2 MIMO mode includes a first RF chain coupled with a first dual band antenna and configured to both transmit (Tx) and receive (Rx) using two different RF protocols. The 2×2 MIMO mode also includes a second RF chain coupled with a second dual band antenna and configured to both Tx and Rx using a single RF protocol. The first RF chain may be coupled with a third antenna configured for near field proximity sensing. The RF architecture is reversibly switchable from the 2×2 MIMO mode to the 1×2 MIMO mode when near field proximity detection is required. In the 1×2 MIMO mode the Tx/Rx capabilities of the second chain using the second dual band antenna are retained and the first chain is configured for Rx only capability using the third antenna.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of co-pending U.S. patent application Ser. No. 13/957,337, filed on Aug. 1, 2013, having Attorney Docket No. ALI-233, and entitled, “RF Architecture Utilizing a Mimo Chipset for Near Field Proximity Sensing and Communication,” U.S. patent application Ser. No. 13/957,337 is related to the following applications: U.S. patent application Ser. No. 13/952,532, filed on Jul. 26, 2013, having Attorney Docket No. ALI-232, and entitled “Radio Signal Pickup From An Electrically Conductive Substrate Utilizing Passive Slits,” U.S. patent application Ser. No. 13/919,307, filed on Jun. 17, 2013, having Attorney Docket No. ALI-206, and entitled “Determining Proximity For Devices Interacting With Media Devices,” and U.S. patent application Ser. No. 13/802,646, filed on Mar. 13, 2013, having Attorney Docket No. ALI-230, and entitled “Proximity-Based Control Of Media Devices For Media Presentations,” all of which are hereby incorporated by reference in their entirety for all purposes. 
     
    
     FIELD 
       [0002]    These present application relates generally to the field of personal electronics, portable electronics, media presentation devices, audio systems, and more specifically to a RF architecture that is reversibly switchable between a 2×2 MIMO mode and a 1×2 MIMO mode while maintaining dual band RF communications in either mode and receive only near field proximity detection in the 1×2 MIMO mode. 
       BACKGROUND 
       [0003]    MIMO is an abbreviation for Multiple-Input Multiple Output RF devices that have the ability to simultaneously handle multiple RF data inputs and multiple RF data outputs. RF devices that include MIMO capability may use a RF antenna to send and receive more than one communication signal simultaneously. For example, transmitting a WiFi signal using a dual band antenna and receiving a Bluetooth (BT) signal using the same dual band antenna. A 2×2 MIMO architecture may provide two RF paths that use two RF chains with each chain configured for receiving and transmitting a RF signal. A 1×1 MIMO architecture, also called SISO, allows for one RF path with a single RF chain that is capable of transmitting or receiving a RF signal. MIMO systems that use multiple RF antennas can take advantage of multipath effects that result in improved range and capacity due to more reliable signal quality and increased bandwidth. 
         [0004]    The MIMO architectures may utilize one or more antennas or a dual band antenna to transmit and receive RF signals. Those antennas are typically optimized for the intended RF bands the MIMO will be in communications with, such as WiFi (2.4 GHz, 5 GHz) and Bluetooth, for example. However, some systems that incorporate a MIMO architecture may include features that requires an antenna optimized for another function, such as near field proximity detection. In some applications, the antenna to be used for near field proximity detection may be subject to design constraints such as imposed by industrial design considerations (e.g., esthetic requirements), chassis/enclosure design, just to name a few. In other applications, the antenna to be used for near field proximity detection may be configured to not be optimized for any of the frequency bands used by the MIMO. For example, it may be desirable to have an intentionally detuned antenna for antenna for near field proximity detection because it will be less sensitive to signal strength (e.g., RSSI) generated by transmitting devices in the far field region (e.g., &gt;0.5 meters from the antenna) and more sensitive to transmitting devices that are in the near field or very near field (e.g., &lt;0.5 meters from the antenna) or are in direct contact with the antenna. Therefore an antenna that is detuned and/or not optimized for RF bands such as those used for WiFi or Bluetooth, may be desirable for some applications that also include a MIMO architecture. 
         [0005]    Thus, there is a need for a RF architecture that takes advantage of MIMO while also incorporating antennas optimized for near field proximity detection into the MIMO architecture while maintaining the advantages of the MIMO architecture. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    Various embodiments or examples (“examples”) of the present application are disclosed in the following detailed description and the accompanying drawings. The drawings are not necessarily to scale: 
           [0007]      FIG. 1A  depicts a block diagram of one example of a RF frontend architecture, according to an embodiment of the present application; 
           [0008]      FIG. 1B  depicts a block diagram of the RF frontend architecture of  FIG. 1A  when set to a 2×2 MIMO mode, according to an embodiment of the present application; 
           [0009]      FIG. 1C  depicts a block diagram of the RF frontend architecture of  FIG. 1A  when set to a 1×2 MIMO mode, according to an embodiment of the present application; 
           [0010]      FIG. 1D  depicts a more detailed block diagram of one example of a RF frontend architecture, according to an embodiment of the present application; 
           [0011]      FIG. 1E  depicts a block diagram of the RF frontend architecture of  FIG. 1D  when set to a 2×2 MIMO mode, according to an embodiment of the present application; 
           [0012]      FIG. 1F  depicts a block diagram of the RF frontend architecture of  FIG. 1D  when set to a 1×2 MIMO mode, according to an embodiment of the present application; 
           [0013]      FIG. 2  depicts an exemplary computer system according to an embodiment of the present application; 
           [0014]      FIG. 3  depicts a flow diagram of one example of a method for multi-channel dual band wireless communication and wireless near field proximity detection, according to an embodiment of the present application; 
           [0015]      FIG. 4A  depicts a top plan view of one example of an antenna and passive slits formed in a substrate of an electrically conductive material, according to an embodiment of the present application; 
           [0016]      FIG. 4B  depicts a cross-sectional view along line AA-AA of  FIG. 4A  of an antenna and passive slits formed in a substrate of an electrically conductive material, according to an embodiment of the present application; 
           [0017]      FIG. 4C  depicts an example schematic diagram of electrical connections with the antenna, according to an embodiment of the present application; and 
           [0018]      FIGS. 4D-4E  depict examples of a live device generating a RF signal that may be detected by a system using an antenna and passive slits, according to an embodiment of the present application. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    Various embodiments or examples may be implemented in numerous ways, including as a system, a process, an apparatus, a user interface, or a series of program instructions on a non-transitory computer readable medium such as a computer readable storage medium or a computer network where the program instructions are sent over optical, electronic, or wireless communication links. In general, operations of disclosed processes may be performed in an arbitrary order, unless otherwise provided in the claims. 
         [0020]    A detailed description of one or more examples is provided below along with accompanying drawing FIGS. The detailed description is provided in connection with such examples, but is not limited to any particular example. The scope is limited only by the claims and numerous alternatives, modifications, and equivalents are encompassed. Numerous specific details are set forth in the following description in order to provide a thorough understanding. These details are provided for the purpose of example and the described techniques may be practiced according to the claims without some or all of these specific details. For clarity, technical material that is known in the technical fields related to the examples has not been described in detail to avoid unnecessarily obscuring the description. 
         [0021]      FIG. 1A  depicts a block diagram  100   a  of one example of a RF frontend architecture  100  (RF  100  hereinafter). Unless otherwise stated, elements in RF  100  may be implemented using a variety of technologies including but not limited to an integrated circuit (IC), a mixed-signal IC, an application specific integrated circuit (ASIC), a mixed signal ASIC, discrete electronic components, combinations of discrete electronic components and IC&#39;s or ASIC&#39;s, just to name a few. RF  100  includes RF circuitry  150  having circuitry for a 2×2 Multiple-Input Multiple-Output (MIMO) and a 1×2 MIMO. One or more signals (e.g.,  157 ,  155 ), either internal to RF  100 , external to RF  100 , or both may be used to set a 2×2 MIMO mode or 1×2 MIMO mode. For example, a mode signal  155  received by RF circuitry  150  may be used to determine with of the two MIMO modes is set. As one example, if the mode signal  155  is active high, then the 2×2 MIMO mode is set, and if the mode signal  155  is active low, then the 1×2 MIMO mode is set. In other examples, another signal or group of signals may set the MIMO mode or cause the mode signal  155  to be set to one of the two MIMO modes. For example, one or more signals on port  157  of RF circuitry  150  may be used to set the MIMO state or cause the mode signal  155  to be set to a particular value or voltage level (e.g., logic 1 or logic 0). 
         [0022]    RF circuitry  150  may include two separate RF chains and their associated circuitry and antennas. For purposes of explanation, a dashed line  143  will be used to visually demark a first RF chain  151  from a second RF chain  152  so that the functionality of the two RF chains may be described with clarity. In the first RF chain  151 , circuitry  129  may be electrically coupled ( 125 ,  127 ) with RF circuitry  150  and a RF switch  160 . Connections  125  and  127  may be for ports on RF circuitry  150  that support different RF bands such as 2.4 GHz, 5 GHz, and Bluetooth (BT), for example. Connections  125  and  127  may also be used to couple RF signals such as those associated with antenna  130  as will be described below. RF chain  151  may include two antennas such as antenna  120  and antenna  130 , both of which are electrically coupled ( 126 ,  136 ) with RF switch  160 . RF switch  160  may select between antennas  120  and  130  based on a signal  153  received by the switch  160  from RF circuitry  150 . Antenna  120  may be a dual band antenna or a dual band chip antenna. The dual band chip antenna may be monolithically integrated with a semiconductor die that include some or all of the circuitry in RF  100  and/or RF circuitry  150 . The dual band chip antenna may be positioned (e.g., floor planned) at a specific location on the die such as at a corner or a side of the die. There may be multiple dual band chip antennas and those antennas may be positioned at opposing corners of the die or at opposing sides or edges, for example. Antenna  130  may be an antenna specifically configured for near field detection of external sources of RF signals. For example, antenna  130  may be a near field proximity detection antenna configured to generate a RF signal when a transmitting RF device is placed directly on or in contact with antenna  130 , or positioned in near field proximity or very close near field proximity of antenna  130 . Very close near field proximity may comprise a distance from the antenna  130  that is approximately 0.5 meters or less. More preferably, 50 mm or less. Even more preferably, 30 mm or less. Near field proximity may comprise a distance that is greater than 0.5 meters. The foregoing are non-limiting examples of what may define near field proximity or very close near field proximity and actual values will be application dependent. Antenna  130  may be configured to be intentionally detuned (e.g., to a lower frequency) from a target frequency, such as the frequency or frequencies of the external sources of RF signals and/or one or more of the dual band frequencies of RF  100 . For example, if the target frequency is 2.4 GHz, then antenna  130  may be detuned to a lower frequency that may be approximately in a range from about 0.5 GHz to about 1.0 GHz. Antenna  130  will be described in greater detail below. Examples of target frequencies include but are not limited to: 2.4 GHz; 2.4 GHz-2.48 GHz; from about 2.4 GHz to about 2.48 GHz; 5 GHz; unlicensed bands, licensed bands, cellular bands, bands used by 2G, 3G, 4G, and 5G devices, Bluetooth bands, any of the 802.11 bands, military bands, just to name a few. Antenna  130  may be tuned to the target frequency or in some examples may be detuned to a frequency range that is below that (i.e., lower) of the target frequency or to a frequency range that is above (i.e., greater) that of the target frequency. 
         [0023]    RF chain  152  includes circuitry  119  that may be electrically coupled ( 115 ,  117 ) with RF circuitry  150 . Connections  115  and  117  may be for ports on RF circuitry  150  that support different RF bands such as 2.4 GHz, 5 GHz, and Bluetooth (BT), for example. RF chain  152  may include an antenna  110  that may be a dual band antenna or a dual band chip antenna as described above for antenna  120 . RF circuitry  150  may support multiple MIMO modes, such as a 2×2 MIMO mode and a 1×2 MIMO mode and RF circuitry  150  may reversibly switch between the multiple MIMO modes, such as between 2×2 MIMO and 1×2 MIMO modes (e.g., in response to signal  155  and/or  157 ). When the 2×2 MIMO mode is set, RF circuitry  150  is configured for dual band RF communication for both transmit (Tx) and receive (Rx) using both antennas ( 110 ,  120 ). Moreover, the dual band RF communications may occur simultaneously such that RF chain  151  may use its antenna  120  to Tx/Rx on dual RF bands, such as WiFi 2.4 GHz and/or WiFi 5 GHz or Bluetooth and/or WiFi 5 GHz. Similarly, RF chain  152  may use its antenna  110  to Tx/Rx on dual RF bands, such as WiFi 2.4 GHz and/or WiFi 5 GHz or Bluetooth and/or WiFi 5 GHz. RF circuitry  150  may be configured so both of the RF chains ( 151 ,  152 ) may Tx/Rx using Bluetooth, or only one of the RF chains ( 151 ,  152 ) may Tx/Rx using Bluetooth (e.g., BT on RF chain  152  only). Ports  115 ,  117 ,  125 , and  127  may be configured for different frequency bands. For example, ports  115  and  125  may be assigned for a RF band such as 2.4 GHz, and ports  117  and  127  may be assigned to another RF band such as 5 GHz. In some applications, all of the ports ( 115 ,  117 ,  125 , and  127 ) may be simultaneously Tx/Rx RF signals over their respective RF bands and in other application some or all of the ports ( 115 ,  117 ,  125 , and  127 ) may be idle. Actual port traffic may be determined by a system or device that incorporates RF  100 . 
       2×2 MIMO Mode 
       [0024]    In  FIGS. 1A and 1B , for purposes of explanation, assume mode signal  155  is set to the 2×2 MIMO mode. In the 2×2 MIMO mode, RF switch  160  electrically couples  161  the antenna  120  with circuitry  129  and dual bandwidth RF communication using antenna  120  is enabled such that dual RF bands denoted as B 1  and B 2  may both simultaneously Tx  122  and Rx  124  RF signals via electrical coupling  128  between circuitry  129  and antenna  120 . Here B 1  may be associated with port  125  and B 2  with port  127 . While in the 2×2 MIMO mode, antenna  130  is electrically decoupled from circuitry  129  by switch  160 . Antenna  130  may be tuned to a fifth RF signal denoted as Rx  134 . However, in the 2×2 MIMO mode, if Rx  134  is incident on antenna  130 , then a resulting signal is not electrically coupled  136  with circuitry  129  because RF switch  160  is set to electrically couple  161  with antenna  120  thereby switching out B 5  for Rx  134 . Furthermore, while in the 2×2 MIMO mode the circuitry  119  is electrically coupled with antenna  110  and dual RF bands denoted as B 3  and B 4  may both simultaneously Tx  112  and Rx  114  RF signals via electrical coupling  116  between circuitry  119  and antenna  110 . Therefore, four RF bands (B 1 -B 4 ) may be active for Tx and Rx in the 2×2 MIMO mode and RF signal reception over B 5  is blocked because antenna  130  is switched out. 
       1×2 MIMO Mode 
       [0025]    Moving now to  FIG. 1C , for purposes of explanation, assume mode signal  155  is set to the 1×2 MIMO mode. In the 1×2 MIMO mode, RF switch  160  electrically couples  163  the antenna  130  with circuitry  129  and dual bandwidth RF communication (B 1 , B 2 ) using antenna  120  is disabled because the antenna  120  is switched out. Here, when antenna  130  has Rx  134  incident on it a signal may be electrically communicated ( 136 ,  138 ) to circuitry  129  and that signal may be processed by RF circuitry  150  or other. The processing may be used to determine relative signal strength based on the signal, or to make received signal strength indicator (RSSI) measurements based on the signal. Furthermore, while in the 1×2 MIMO mode the circuitry  119  is electrically coupled with antenna  110  and dual RF bands (B 3 , B 4 ) and both bands may simultaneously Tx  112  and Rx  114  RF signals via electrical coupling  116  between circuitry  119  and antenna  110 . Therefore, two RF bands (B 3 -B 4 ) may be active for Tx and Rx in the 1×2 MIMO mode in RF chain  152  and RF signals may be received only in RF chain  151  via antenna  130 . Tx and Rx over B 1  and B 2  is blocked in the 1×2 MIMO mode because antenna  120  is switched out. 
         [0026]      FIG. 1D  depicts a more detailed block diagram  100   d  of one example of RF  100 . In RF chain  151 , circuitry  129  may include a band pass filter (BPF)  191  coupled ( 125 ,  195   a ) with the RF circuitry  150  and a diplexer  195 . Diplexer  195  may be electrically coupled  160   a  with an output of RF switch  160 . A matching circuit  193  may be electrically coupled ( 120   a ,  120   b ) with antenna  120  and an input to RF switch  160 . At least a portion of antenna  130  may be exposed (Exp) (see  FIGS. 4A-4E ) to facilitate near field detection of external RF transmitting devices (e.g., a smartphone, tablet, or pad). Additional circuitry may include an electrostatic discharge (ESD) protection circuit  190 , a matching circuit  192 , and an attenuator  194  electrically coupled ( 130   d ,  130   c ,  130   b , and  130   a ) between the antenna  130  and RF switch  160 . In RF chain  152 , BPF&#39;s  181  and  183  may be electrically coupled ( 115 ,  117 ,  180   a , and  180   b ) between a diplexer  185  and RF circuitry  150 , and a matching circuit  187  may be electrically coupled ( 110   a ,  110   b ) between the diplexer  185  and antenna  110 . 
         [0027]    In  FIG. 1E , setting the mode signal to the 2×2 MIMO mode is operative to generate a signal on  153  that causes RF switch  160  to deselect antenna  130  for B 5  (e.g., Rx on B 5  is switched out) as denoted by a dashed line for input  130   d  to RF switch  160 , and to select antenna  120  as denoted by a solid line for input  120   b . Therefore, in the 2×2 MIMO mode, B 5  is blocked and B 1 , B 2 , B 3  and B 4  are all available for Tx/Rx in RF chains  151  and  152 . 
         [0028]    In  FIG. 1F , setting the mode signal to the 1×2 MIMO mode is operative to generate a signal on  153  that causes RF switch  160  to deselect antenna  120  thereby switching out Tx/Rx on B 1  and B 2  as denoted by a dashed line for input  120   b  to RF switch  160 . Antenna  120  is selected as denoted by a solid line for input  130   d  to RF switch  160 . Therefore, in the 2×2 MIMO mode, B 5  is available for Rx only, B 1  and B 2  are blocked for both Tx and Rx, and B 3  and B 4  in RF chain  152  are both available for Tx and Rx. 
         [0029]      FIG. 2  depicts an exemplary computer system  200  suitable for use in the systems, methods, and apparatus described herein. In some examples, computer system  200  may be used to implement circuitry, computer programs, applications (e.g., APP&#39;s), configurations (e.g., CFG&#39;s), methods, processes, or other hardware and/or software to perform the above-described techniques. Computer system  200  includes a bus  202  or other communication mechanism for communicating information, which interconnects subsystems and devices, such as one or more processors  204 , system memory  206  (e.g., RAM, SRAM, DRAM, Flash), storage device  208  (e.g., Flash, ROM), disk drive  210  (e.g., magnetic, optical, solid state), communication interface  212  (e.g., modem, Ethernet, WiFi), display  214  (e.g., CRT, LCD, touch screen), one or more input devices  216  (e.g., keyboard, stylus, touch screen display), cursor control  218  (e.g., mouse, trackball, stylus), one or more peripherals  240 . Some of the elements depicted in computer system  200  may be optional, such as elements  214 - 218  and  240 , for example and computer system  200  need not include all of the elements depicted. 
         [0030]    According to some examples, computer system  200  performs specific operations by processor  204  executing one or more sequences of one or more instructions stored in system memory  206 . Such instructions may be read into system memory  206  from another non-transitory computer readable medium, such as storage device  208  or disk drive  210  (e.g., a HD or SSD). In some examples, circuitry may be used in place of or in combination with software instructions for implementation. The term “non-transitory computer readable medium” refers to any tangible medium that participates in providing instructions to processor  204  for execution. Such a medium may take many forms, including but not limited to, non-volatile media and volatile media. Non-volatile media includes, for example, optical, magnetic, or solid state disks, such as disk drive  210 . Volatile media includes dynamic memory, such as system memory  206 . Common forms of non-transitory computer readable media includes, for example, floppy disk, flexible disk, hard disk, SSD, magnetic tape, any other magnetic medium, CD-ROM, DVD-ROM, Blu-Ray ROM, USB thumb drive, SD Card, any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, RAM, PROM, EPROM, FLASH-EPROM, any other memory chip or cartridge, or any other medium from which a computer may read. 
         [0031]    Instructions may further be transmitted or received using a transmission medium. The term “transmission medium” may include any tangible or intangible medium that is capable of storing, encoding or carrying instructions for execution by the machine, and includes digital or analog communications signals or other intangible medium to facilitate communication of such instructions. Transmission media includes coaxial cables, copper wire, and fiber optics, including wires that comprise bus  202  for transmitting a computer data signal. In some examples, execution of the sequences of instructions may be performed by a single computer system  200 . According to some examples, two or more computer systems  200  coupled by communication link  220  (e.g., LAN, Ethernet, PSTN, or wireless network) may perform the sequence of instructions in coordination with one another. Computer system  200  may transmit and receive messages, data, and instructions, including programs, (i.e., application code), through communication link  220  and communication interface  212 . Received program code may be executed by processor  204  as it is received, and/or stored in a drive unit  210  (e.g., a SSD or HD) or other non-volatile storage for later execution. Computer system  200  may optionally include one or more wireless systems  213  in communication with the communication interface  212  and coupled ( 215 ,  223 ) with one or more antennas ( 217 ,  225 ) for receiving and/or transmitting RF signals ( 221 ,  227 ), such as from a WiFi network, BT radio, or other wireless network and/or wireless devices, for example. Examples of wireless devices include but are not limited to: a data capable strap band, wristband, wristwatch, digital watch, or wireless activity monitoring and reporting device; a smartphone; cellular phone; tablet; tablet computer; pad device (e.g., an iPad); touch screen device; touch screen computer; laptop computer; personal computer; server; personal digital assistant (PDA); portable gaming device; a mobile electronic device; and a wireless media device, just to name a few. Computer system  200  in part or whole may be used to implement one or more systems, devices, or methods using the antenna and passive slits as described herein. For example, a radio (e.g., a RF receiver) in wireless system(s)  213  may be electrically coupled  231  with an edge of the antenna. Computer system  200  in part or whole may be used to implement a remote server or other compute engine in communication with systems, devices, or method using the antenna and passive slits as described herein. RF  100  may be included in the wireless system(s)  213 . 
         [0032]      FIG. 3  depicts a flow diagram  300  of one example a method for multi-channel dual band wireless communication and wireless near field proximity detection. At a stage  301  a state of a MIMO mode signal (e.g., mode  153 ) is set to a 1×2 MIMO mode or a 2×2 MIMO mode. An external signal may be used to set and/or toggle a state of the MIMO mode signal. As one example, a user pressing or otherwise actuating a switch, button, capacitive switch, touch screen, or other device may trigger the generation and/or toggling of the MIMO mode signal. At a stage  303  a determination may be made as to whether or not the MIMO mode signal is set to a 1×2 MIMO mode. If the state of the MIMO mode signal is set to the 1×2 MIMO mode, then a YES branch is taken to a stage  305  where the RF chain  151  couples the antenna  130  for Rx only on B 5  and RF chain  152  couples antenna  110  for both Tx and Rx on B 3  and B 4 . At a stage  311  a determination may be made as to whether or not the MIMO mode signal has changed since being set to the 1×2 MIMO mode. If the MIMO mode signal has not changed, then a NO branch may be taken and flow  300  may end. If the MIMO mode signal has changed, then a YES branch may return flow back to a prior stage, such as the stage  303 , for example. 
         [0033]    Back at the stage  303 , if the 1×2 MIMO mode has not been set, then a NO branch may be taken to a stage  307  where a determination may be made as to whether or not the MIMO mode signal is set to a 2×2 MIMO mode. If the state of the MIMO mode signal is set to the 2×2 MIMO mode, then a YES branch is taken to a stage  309  where the RF chain  151  couples antenna  120  for Tx and Rx on B 1  and B 2 , antenna  130  is decoupled so that Rx on B 5  is blocked, and RF chain  152  couples antenna  110  for both Tx and Rx on B 3  and B 4 . If the 2×2 MIMO mode is not set, then a NO branch may be taken and the flow  300  may return to a prior stage, such as the stage  301 , for example. At the stage  311 , the flow  300  may end if there is no change in the MIMO mode signal or may flow back to a prior stage, such as the stage  303 , for example. 
         [0034]    Table 1 below lists examples of which bands (B 1 -B 5 ) may Tx or Rx depending on the state of the MIMO mode signal. 
         [0000]    
       
         
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 Band 
                 2X2 MIMO Mode 
                 1X2 MIMO Mode 
               
               
                   
                   
               
             
             
               
                   
                 B1 
                 Tx and Rx on 120 
                 NO Tx or Rx on 120 
               
               
                   
                 B2 
                 Tx and Rx on 120 
                 NO Tx or Rx on 120 
               
               
                   
                 B3 
                 Tx and Rx on 110 
                 Tx and Rx on 110 
               
               
                   
                 B4 
                 Tx and Rx on 110 
                 Tx and Rx on 110 
               
               
                   
                 B5 
                 NO Rx on 130 
                 Rx only on 130 
               
               
                   
                   
               
             
          
         
       
     
         [0035]    Table 2 below lists examples of frequencies for bands (B 1 -B 5 ) depending on the state of the MIMO mode signal. 
         [0000]    
       
         
               
               
               
               
             
           
               
                   
                 TABLE 2 
               
               
                   
                   
               
               
                   
                 Band 
                 2X2 MIMO Mode 
                 1X2 MIMO Mode 
               
               
                   
                   
               
             
             
               
                   
                 B1 
                 2.4 GHz WiFi on 120 
                 NO Tx or Rx on 120 
               
               
                   
                 B2 
                 5 GHz WiFi on 120 
                 NO Tx or Rx on 120 
               
               
                   
                 B3 
                 2.4 GHz WiFi on 110 
                 2.4 GHz WiFi on 110 
               
               
                   
                 B4 
                 5 GHz WiFi on 110 
                 5 GHz WiFi on 110 
               
               
                   
                 B1 
                 BT on 120 
                 NO Tx or Rx on 120 
               
               
                   
                 B2 
                 5 GHz WiFi on 120 
                 NO Tx or Rx on 120 
               
               
                   
                 B3 
                 BT on 110 
                 BT on 110 
               
               
                   
                 B4 
                 5 GHz WiFi on 110 
                 5 GHz WiFi on 110 
               
               
                   
                 B5 
                 NO Rx on 130 
                 Rx** only on 130 
               
               
                   
                   
               
             
          
         
       
     
         [0036]    Although Table 2 lists both B 1  and B 3  as being enabled for Bluetooth Tx and Rx, as was stated above, in some configurations, both B 1  and B 3  may Tx and Rx using Bluetooth, and in other configurations only B 1  or B 3  may Tx and Rx using Bluetooth. In some configurations B 1 , B 3 , or both may switch between Tx and Rx on 2.4 GHz WiFi to Tx and Rx on Bluetooth as needed. For example, in 2×2 MIMO mode, B 1  may initially Tx and Rx over 120 using 2.4 GHz WiFi and then switch to Tx and Rx on Bluetooth when a BT enabled device is paired with or otherwise establishes a BT communications link with RF  100 . While B 1  continues to Tx and Rx on Bluetooth in the 2×2 MIMO mode, B 3  may service the Tx and Rx 2.4 GHz WiFi traffic until B 1  again becomes available for 2.4 GHz WiFi communications. The “**” in the column for 1×2 MIMO mode for B 5  denotes that antenna  130  may be detuned for optimal performance at some frequency that is lower than those for (B 1 -B 4 ) as described above. 
         [0037]    Antenna Using Passive Slits 
         [0038]      FIG. 4A  depicts a top plan view  490   a  of a substrate of an electrically conductive material  450  in which a plurality of separate apertures (e.g., holes or openings) are formed. Here, those separate apertures are depicted looking down on a surface  451  of the substrate  450 . Therefore, the separate apertures may be described as through holes formed in the substrate  450  and extending all the way through the substrate  450  as will be described in greater detail in  FIG. 4B . 
         [0039]    One or more of the separate apertures comprises an antenna  130  having a length dimension L that is substantially larger that a width dimension H. For example, if antenna  130  has the shape of a rectangle as depicted in  FIG. 4A , then H is much less than L (e.g., H&lt;&lt;L), such that if L is 150 mm then H may be 10 mm or less (e.g., H=3.5 mm). Actual shapes and dimensions of the antenna  130  may be application dependent and are not limited to the configuration depicted in  FIG. 4A  or in any other figures herein. One edge  410  of antenna  130  is electrically coupled with a radio frequency (RF) system (e.g., RF  100 ) and an opposite edge  412  is electrically coupled with a ground potential (not shown) (e.g., a ground—GND or chassis ground). Edges  410  and  412  are along a length dimension of the antenna  130 . As one example, a node  411  on edge  410  may be electrically coupled with the RF system and another node  413  on the opposite edge  412  may be electrically coupled with the ground potential. In some examples, the electrical connections for nodes  411  and  413  may be reversed and node  413  electrically coupled with the RF system and node  411  electrical coupled with the ground potential. Although the position of the electrical connections to the edges  410  and  412  are depicted directly opposite each other, that is node  411  is directly opposite node  413 , the nodes may be positioned along their respective edges at other locations and the configuration depicted is a non-limiting example. Although one antenna  130  is depicted there may be a plurality of antennas as denoted by  421 . 
         [0040]    Substrate  450  also includes one or more apertures that define a passive slit denoted as  401  and  403 . Although two passive slits ( 401 ,  403 ) are depicted there may be just a single passive slit or more than two passive slits as denoted by  423 . Moreover, the relative position on the substrate  450  of the passive slit(s) and the antenna(s) are not limited to the configurations depicted in  FIG. 4A  or in other figures herein and the actual size, shape, dimensions, and positions of the passive slit(s) and/or antenna(s) may be application dependent. Passive slits ( 401 ,  403 ) are not electrically coupled with circuitry, the ground potential, or the RF system. Passive slits ( 401 ,  403 ) are passive structures formed in the substrate  450  and may operate to modify current flow along substrate  450  generated by interaction of an external RF signal (e.g., Rx  134 ) with antenna  130  as will be described below. Passive slits ( 401 ,  403 ) are not driven by circuitry nor do they generate a signal that is coupled with circuitry (e.g., circuitry in RF  100 ). 
         [0041]    Typically, dimensions of the passive slits ( 401 ,  403 ) may be much less than similar dimensions of the antenna  130 . For example, if the passive slits ( 401 ,  403 ) are rectangular in shape as depicted in  FIG. 4A , then a width dimension W of passive slits ( 401 ,  403 ) may be less than the width dimension H of the antenna  130 . For example, if H is 5 mm, then W may be 1.5 mm. Moreover, if the length L of the antenna  130  is 150 mm then length D may be 53 mm for the passive slits ( 401 ,  403 ). Passive slits ( 401 ,  403 ) may be placed at various positions along surface  451  of substrate  450 , such as opposite ends of antenna  130 , for example. In that the plurality of apertures are spatially separate from one another, passive slits ( 401 ,  403 ) may be spaced apart from antenna  130  by a distance S that may be the same or different for each passive slit ( 401 ,  403 ). 
         [0042]    In that the antenna  130  and passive slits ( 401 ,  403 ) are apertures formed in substrate  450 , a void in the opening defined by the apertures, denoted as  402   a  for the antenna  130  and  402   b  for the passive slits ( 401 ,  403 ), may be occupied by air or some other electrically non-conductive material, medium, dielectric material, or composition of matter. Examples of suitable materials includes but is not limited to rubber, plastics, glass, wood, stone, a gas, paper, inert organic or inorganic materials, cloth, leather, a liquid, Teflon, PVDF, minerals, just to name a few. A material that occupies the void/opening may be selected for a functional purpose, an esthetic purpose, or both. In some applications a functional element such as a switch, button, actuator, indicator (e.g., a LED), microphone, transducer, or the like may be positioned in void/opening ( 402   a ,  402   b ). In other applications the material disposed in the void/opening ( 402   a ,  402   b ) may include a logo, a trademark, a service mark, ASCII characters, graphics, patterns, one or more esthetic features, instructions, or the like. 
         [0043]    Moving on to  FIG. 4B , a cross-sectional view  490   b  of the substrate  450  depicts in greater detail the void/opening ( 402   a ,  402   b ) of the apertures for antenna  130  and passive slits ( 401 ,  403 ). Surfaces  451  and  453  of substrate  450  are depicted as being substantially parallel to each other; however, substrate  450  may have a thickness T that varies and need not be flat, planar, or smooth. Moreover, substrate  450  may have a shape including but not limited to an arcuate shape, curvilinear shape, an undulating shape, and a complex shape, just to name a few. Substrate  450  may be made from a perforate material such as a screen, mesh, or other material with perforations formed in it. 
         [0044]    Attention is now directed to  FIG. 4C  where a schematic diagram  190   c  depicts one example of how the opposing sides ( 410 ,  412 ) along the length L dimension of the antenna  130  may be electrically coupled. Node  411  on side  410  is electrically coupled (e.g.,  136 ,  130   d ,  463 ) with a RF  100 . The electrical coupling (e.g.,  136 ,  130   d ,  463  to RF Switch  160 ) may be made using a variety of connection techniques including but not limited to a RF feed, coaxial cable, a wire, a shielded connection, an unshielded connection, a partially shielded connection, an electrically conductive trace, just to name a few. A node  465  of RF  100  may include a termination device  461 , such as a SMA connector or the like, configured to make an impedance matching termination, such as 50 ohms, for example. Node  413  on side  412  is electrically coupled  471  with a ground potential  470 . The ground potential  470  may include but is not limited to a chassis ground, circuit ground, and power supply ground, just to name a few. The actual selection of the appropriate ground potential may be application dependent and is not limited to the ground potentials described herein. The electrical coupling  471  may use any suitable electrical connection medium including but not limited to wire, a conductive trace, a cable, and a coaxial cable, just to name a few. RF  100  may one or more RF devices including but not limited to RF transceivers for WiFi, Bluetooth, Ad Hoc WiFi, RF transceivers, RF receivers, and RF transmitters. RF  100  may include a RF device configured for and/or devoted to operation with antenna  130  (e.g., a RF receiver). RF  100  may generate one or more signals on an output  469  in response to RF signals received by antenna  130 . 
         [0045]    In  FIG. 4C , an axis X of the antenna  130  is depicted as being orthogonal to an axis Y of the passive slits ( 401 ,  403 ). However, the configuration depicted is just one non-limiting example and the axis of the antenna  130  and passive slits ( 401 ,  403 ), if any, need not have a particular angular orientation. For example, angle α as measured between the X and Y axes need not be 90 degrees (e.g., a right angle) and other angular relationships may be used. Furthermore, any angular relationship between axes of the antenna  130  and the passive slits ( 401 ,  403 ) may vary such that a for  403  may be different than a for  401 . 
         [0046]    Turning now to  FIGS. 4D-4E  were examples of a live device  477  transmitting  134  a RF signal that may be detected by a system (e.g., RF  100 ) using the antenna  130  and passive slits ( 401 ,  403 ) are depicted. In  FIGS. 4D-4E , nodes  411  and  413  may be connected as described in reference to  FIG. 4C  above. Live device  477  is transmitting Tx a RF signal  134 . There may also be other RF sources in an environment in which the live device  477  and/or substrate  450  (and its associated system) reside and those RF sources are denoted as transmitting Tx sources  461   a - 461   n . RF signals from antennas  110  and  120  (e.g., from B 1 -B 4 ) may also be present in the environment. For purpose of discussion, a live device is a device that is actively transmitting Tx a RF signal or may be activated (e.g., turned on, controlled or commanded) to transmit Tx a RF signal. 
         [0047]    In the cross-sectional view of  FIG. 4E , live device  477  is depicted in its most preferred placement, which is directly on the surface  451  of substrate  450 . Live device  477  may be positioned at a variety of locations on surface  451  and the position on surface  451  is not limited to the position(s) depicted herein. However, in some applications the live device  477  may be placed above the surface  451  at a distance  480   d  that is in very close near field proximity of the surface  451  of the substrate  450  and its associated antenna  130  and passive slits ( 401 ,  403 ). Although the received RF signal Rx  134  may be at its strongest when the live device  477  is at  480 =0 (e.g., directly on surface  451 ), there may be circumstances where the live device  477  is positioned in very close near field proximity of the surface  451 . In the very near field region, the power drop off of RF signal strength may be larger than the well understood 1/R 2  power drop off rate, and the power drop off may be 1/R 3  or even 1/R 4 . Therefore, even small distances from surface  451  may result in a large power drop off in RF signal strength as received by antenna  130  and detected by RF  100 . Distance  480  is preferably 0.5 meters or less, more preferably 50 mm or less, and even more preferably 30 mm or less. Actual distances for very close near field proximity will be application dependent and are not limited to the examples described herein. The live device  477  may comprise a wide variety of wirelessly enabled devices including but not limited to a smartphone, gaming device, tablet or pad, wireless headset or earpiece, a laptop computer, an image capture device, a wireless wristwatch or timepiece, a data capable strapband or wristband, just to name a few. In some examples, live device  477  may be positioned in near field proximity (e.g., from about 0.5 meters to about 1 meter) of surface  451  of the substrate  450  and its associated antenna  130  and passive slits ( 401 ,  403 ). Actual distances for near field proximity will be application dependent and are not limited to the examples described herein. Here, near field proximity may be represented by a distance  481  from surface  451 , where the distance for near field proximity is greater than the distance for very close near field proximity (e.g.,  481 &gt; 480 ). Therefore, near field proximity may be regarded as a distance that begins approximately were very close near field proximity ends, as denoted by dashed line  482 , and extending to an approximate distance denoted by dashed line  483 . 
         [0048]    In some examples, a user may trigger a mode switch from 2×2 MIMO mode to 1×2 MIMO mode by actuating or pressing a button or the like on a chassis or other structure that houses the substrate  450 , such as button  488  on surface  451 . Button  488  may be a capacitive touch switch or the like. Button  488  may be positioned at some other location and need not be on substrate  450 . The user may press button  488  to signal to a device or system that includes RF  100  that an attempt will presently be made to position a live device (e.g., device  477 ) directly on top of substrate  450  or into very close near field proximity of substrate  450 . RF switch  160  may be signaled  153  to decouple antenna  120  and couple antenna  130  (e.g., in 1×2 MIMO mode) in preparation for detecting Rx  134  from the live device (e.g., device  477 ). In other examples, an application (APP) or other form of software running on the live device  477  may signal RF  100  using one of its radios (e.g., WiFi or BT) that the live device will presently be positioned directly on or in very close near field proximity of substrate  450 . A user may activate the APP using a GUI or other interface provide on a touch screen display or the like on the live device  477  (e.g., a smartphone, tablet, or pad). 
         [0049]    In some examples, RF  100  may be configured to switch between 2×2 MIMO mode and 1×2 MIMO mode upon occurrence of some event that may be detected using antennas  110  and/or  120 . For example, RF  100  may recognize a RF signature (e.g., via packet sniffing or the like) of a previously recognized wireless device that is typically placed on the substrate  450 . RF  100  may upon recognizing the RF signature begin switching back and forth between 2×2 MIMO mode and 1×2 MIMO mode to see antenna  130  detects the proximity of the wireless device while the 1×2 MIMO mode is active. RF  100  or some other system or device in communication with RF  100  may take some action upon detection of a live device (e.g., device  477 ) including but not limited to establishing a wireless link with the live device, transferring content handling from the live device to another device or system, BT pairing with the live device, just to name a few. 
         [0050]    The systems, wireless media devices, apparatus and methods of the foregoing examples may be embodied and/or implemented at least in part as a machine configured to receive a non-transitory computer-readable medium storing computer-readable instructions. The instructions may be executed by computer-executable components preferably integrated with the application, server, network, website, web browser, hardware/firmware/software elements of a user computer or electronic device, or any suitable combination thereof. Other systems and methods of the embodiment may be embodied and/or implemented at least in part as a machine configured to receive a non-transitory computer-readable medium storing computer-readable instructions. The instructions are preferably executed by computer-executable components preferably integrated by computer-executable components preferably integrated with apparatuses and networks of the type described above. The non-transitory computer-readable medium may be stored on any suitable computer readable media such as RAMs, ROMs, Flash memory, EEPROMs, optical devices (CD, DVD or Blu-Ray), hard drives (HD), solid state drives (SSD), floppy drives, or any suitable device. The computer-executable component may preferably be a processor but any suitable dedicated hardware device may (alternatively or additionally) execute the instructions. 
         [0051]    As a person skilled in the art will recognize from the previous detailed description and from the drawing FIGS. and claims set forth below, modifications and changes may be made to the embodiments of the present application without departing from the scope of this present application as defined in the following claims. 
         [0052]    Although the foregoing examples have been described in some detail for purposes of clarity of understanding, the above-described inventive techniques are not limited to the details provided. There are many alternative ways of implementing the above-described techniques or the present application. The disclosed examples are illustrative and not restrictive.