Patent Publication Number: US-8988291-B2

Title: Mobile wireless communications device comprising a satellite positioning system antenna with active and passive elements and related methods

Description:
RELATED APPLICATION 
     This application is a continuation of Ser. No. 12/638,093 filed Dec. 15, 2009, now U.S. Pat. No. 8,063,836, which, in turn, is a continuation of Ser. No. 11/288,896 filed Nov. 29, 2005 now U.S. Pat. No. 7,656,353 issued Feb. 2, 2010, the entire disclosures of which are hereby incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to the field of communications devices, and, more particularly, to mobile wireless communications devices and related methods. 
     BACKGROUND OF THE INVENTION 
     Cellular communications systems continue to grow in popularity and have become an integral part of both personal and business communications. Cellular telephones allow users to place and receive voice calls most anywhere they travel. Moreover, as cellular telephone technology has increased, so too has the functionality of cellular devices. For example, many cellular devices now incorporate personal digital assistant (PDA) features such as calendars, address books, task lists, etc. Moreover, such multi-function devices may also allow users to wirelessly send and receive electronic mail (email) messages and access the Internet via a cellular network and/or a wireless local area network (WLAN), for example. 
     Another feature which is being coupled with cellular communications capabilities is satellite positioning. That is, certain devices now incorporate both cellular and satellite positioning devices, such as global positioning system (GPS) devices, for example. One such device is described in U.S. Pat. No. 6,857,016 to Motoyama et al., which is directed to a computer remote position reporting device which includes a global positioning system (GPS) receiver, monitoring software and an Internet access module for tracking and mapping a position of a mobile object. In one embodiment, the obtained positions are collected, logged and communicated to a desired location by a store-and-forward protocol (e.g., Internet e-mail) or a direct-connection protocol (e.g., file transfer protocol (FTP)) via a wireless cellular transceiver. 
     As the functionality of cellular communications devices continues to increase, so too does the demand for smaller devices which are easier and more convenient for users to carry. As such, incorporating GPS capabilities in ever-smaller cellular phones becomes increasingly difficult, as smaller GPS antenna designs are required due to space constraints. Thus, one challenge for designers is to provide GPS antennas with adequate signal reception characteristics yet in a relatively small size. 
     Various attempts have been made improve mobile device satellite positioning antennas. An antenna arrangement for a GPS signal processing device is disclosed in U.S. Pat. No. 6,720,923 to Hayward et al. in which an antenna member is mounted on a circuit board. The antenna member includes first, second, and third surfaces. The third surface adjoins the first and second surfaces. The first, second and third surfaces define a cavity within which is disposed dielectric material. At least one conductive connector comprising first and second ends is in communication with the antenna member first surface, and an amplifier is in communication with each conductive connector second end. 
     Another example is set forth in PCT publication no. WO 02/29988 A1, which discloses a folded inverted F antenna (FIFA) which includes an L-shaped receiving element having a first planar portion and a second planar portion connected along a fold edge. A printed circuit board (PCB) is disposed perpendicular to the second planar portion forming a PCB ground plane. The FIFA includes a second ground plane disposed below and in parallel with the second planar portion. Shorting conductors couple the receiving element to the PCB and the second ground plane, and a receive conductor couples a receiver circuit to the receiving element. The FIFA is for use in a wireless communications device, such as a cellular phone, for receiving position signals from a GPS satellite. 
     Despite the availability of such GPS antenna configurations, other GPS antenna configurations may be desirable which are relatively compact yet still provide desired beam direction or shaping for optimizing OPS satellite signal reception, for example. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic block diagram of a mobile wireless communications device. 
         FIG. 2  is a schematic block diagram of an alternate embodiment of the mobile wireless communication device of  FIG. 1 . 
         FIG. 3  is a schematic perspective view of a PCB and satellite positioning antenna arrangement for the wireless communications device of  FIG. 1 . 
         FIG. 4  is a schematic diagram of an alternate embodiment of the satellite positioning antenna of  FIG. 3 . 
         FIGS. 5-8  are schematic diagrams of alternate embodiments of satellite positioning antennas for a mobile wireless communications device. 
         FIG. 9  is a schematic block diagram of the wireless communications device of  FIG. 1  illustrating satellite positioning information display features thereof. 
         FIG. 10  is a schematic block diagram of an exemplary mobile wireless communications device arrangement for use with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present description is made with reference to the accompanying drawings, in which preferred embodiments are shown. However, many different embodiments may be used, and thus the description should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete. Like numbers refer to like elements throughout, and prime and multiple prime notation are used to indicate similar elements in alternate embodiments. 
     Generally speaking, a mobile wireless communications device is disclosed herein which may include a portable housing, at least one wireless transceiver carried by the portable housing, and a satellite positioning signal receiver carried by the portable housing. Moreover, a satellite positioning antenna may be carried by the portable housing. The satellite positioning antenna may include an active element connected to the satellite positioning signal receiver, and a passive element connected to a voltage reference and positioned in spaced apart relation from the active element and operatively (e.g., operatively or capacitively) coupled thereto for directing a beam pattern thereof. 
     More particularly, at least one of the active and passive elements may include a tuning feature. Additionally, the passive element may define a U-shaped portion, and a portion of the active element may be positioned within the U-shaped portion of the active element. The passive element may also include a pair of parallel branches, and a portion of the active element may be positioned between the parallel branches of the passive element. Furthermore, the active and passive elements may each include first end portions that are substantially parallel. 
     The mobile wireless communications device may also include a printed circuit board (PCB) carried by the portable housing, and the satellite positioning antenna and the PCB may be relatively positioned so that the PCB further directs the beam pattern of the antenna. By way of example, the active and passive elements may include electrically conductive traces on the PCB. Moreover, a dielectric extension may extend outwardly from the PCB, and the active and passive elements may be carried by the dielectric extension. The active and passive elements may be monopole antenna elements, for example. 
     The portable housing may have an upper portion and a lower portion, and the satellite positioning antenna may be positioned adjacent the upper portion of the portable housing. Furthermore, the at least one wireless transceiver may be a cellular transceiver, and a cellular antenna may also be carried by the portable housing and connected to the cellular transceiver. The mobile wireless communications device may additionally include a controller carried by the portable housing and connected to the satellite positioning signal receiver, and a display carried by the portable housing and cooperating with the controller for displaying satellite positioning information. 
     A method aspect for making a mobile wireless communications device generally includes positioning a satellite positioning signal receiver and at least one wireless transceiver in a portable housing, and connecting an active element of a satellite positioning antenna and carried by the portable housing to the satellite positioning signal receiver. The method may further include positioning a passive element of the satellite positioning antenna connected to a voltage reference in spaced apart relation from the active element and operatively coupled thereto for directing a beam pattern thereof. 
     Referring initially to  FIGS. 1 and 2 , a mobile wireless communications device  20  illustratively includes a portable housing  21  and one or more wireless transceivers  22  carried by the portable housing. In the example illustrated in  FIG. 2 , a cellular transceiver  22 ′ cooperates with a cellular antenna  23 ′ to communicate over a cellular network  24 ′ via a base station(s)  25 ′, which is shown as a cell tower for clarity of illustration. In other embodiments, the wireless transceiver  22  may be a wireless local or personal area network (LAN/PAN) transceiver for communicating via a wireless LAN/PAN, for example. In still further embodiments, both cellular and wireless LAN/PAN transceivers may be included, as will be appreciated by those skilled in the art. 
     The device  20  further illustratively includes a satellite positioning signal receiver  26  carried by the portable housing. By way of example, the satellite positioning signal receiver  26  may be a GPS receiver, although receivers compatible with other satellite positioning systems such as Galileo, for example, may also be used. A satellite positioning antenna  35  is also carried by the portable housing  21  and is connected to the satellite positioning signal receiver  26  for receiving positioning signals from GPS satellites  28 , as will be appreciated by those skilled in the art. 
     More particularly, the satellite positioning antenna  35  illustratively includes an active element  27  connected to the satellite positioning signal receiver  26 , and a passive element  29  connected to a voltage reference (e.g., ground) and positioned in spaced apart relation from the active element and operatively (e.g., inductively or capacitively) coupled thereto for directing a beam pattern thereof. That is, passive element  29  advantageously helps to direct or shape the beam pattern of the active element  27  skyward toward the GPS satellites  28  when the mobile wireless communications device  20  is held in an operating position, as will be discussed further below. 
     Turning now additionally to  FIG. 3 , the mobile wireless communications device  20  may further include a printed circuit board (PCB)  30  carried by the portable housing  21 . Moreover, a dielectric extension  33  illustratively extends outwardly from the PCB  30 , and the active and passive elements  27 ,  29  are carried on an upper surface of the dielectric extension. In the illustrated embodiment, the satellite positioning signal receiver  26  is schematically shown as a signal source on the PCB  30  for clarity of illustration, and the active and passive elements  27 ,  29  are monopole antenna elements comprising printed conductive traces on an upper surface of the dielectric extension  33 . However, other types of antenna elements may be used in other embodiments. 
     The active and passive elements  27 ,  29  and the PCB  30  are relatively positioned, for example in a laterally spaced apart relation, so that the PCB further directs the beam pattern of the active element  27 . More particularly, the PCB  30  will be oriented in a generally vertical direction when held in an operating position by a user. Accordingly, the upper surface of the dielectric extension  33 , which is preferably positioned adjacent the upper portion (i.e., top) of the housing  21 , will therefore be pointing upward or skyward toward the satellites  28 , which along with the generally vertically oriented PCB  30  and the passive element  29  advantageously directs the beam pattern of the active element  27  in this direction, as will be appreciated by those skilled in the art. 
     In an alternate embodiment of the satellite positioning antenna  35 ′ illustrated in  FIG. 4 , the active and passive elements  27 ′,  29 ′ each include respective first end portions  36 ′,  37 ′ that are substantially parallel, similar to the active and passive elements  27 ,  29  illustrated in  FIG. 3 . However, these two embodiments differ in that the feed points for the active and passive elements  27 ,  29  are on opposite ends of the elements, whereas the feed points for the active and passive elements  27 ′,  29 ′ are located at the same end of the elements as shown. Moreover, the passive element  29 ′ includes a tuning feature, namely a U-shaped loop-back portion  38 ′. 
     Other embodiments in which the active element  27  and/or the passive element  29  includes a tuning feature are now described with reference to  FIGS. 5-8 , in which similar elements are indicated with reference numerals incremented by intervals of ten (e.g., the active element  27  is labeled as  57 ,  67 ,  77 , and  87  in  FIGS. 5 ,  6 ,  7 , and  8 , respectively). Generally speaking, a tuning feature may be used to change the electrical length of a conductive element and, thus, the operational characteristics of the antenna, as will be appreciated by those skilled in the art. The various tuning features used in a given embodiment will depend upon the particular configuration of the device and antenna, particularly the amount of space and/or surface area available for implementing the antenna, as will be appreciated by those skilled in the art. 
     In the exemplary embodiments illustrated in  FIGS. 5 and 6 , the active and passive elements  57 ,  59  each has a generally sinusoidal tuning feature. The passive element  79  defines a U-shaped portion, and a portion of the active element  77  is positioned within the U-shaped portion of the passive element. The passive element  89  includes a pair of parallel branches, and a portion of the active element  87  is positioned between the parallel branches of the passive element as shown. Of course, it will be appreciated by those skilled in the art that numerous other tuning features and configurations may be used in different embodiments. 
     Turning now additionally to  FIG. 9 , the device  20  further illustratively includes a controller  31  carried by the portable housing  21  and connected to the satellite positioning signal receiver  26 , and a display  32  carried by the portable housing and cooperating with the controller for displaying satellite positioning information. By way of example, the controller  31  may include a microprocessor and associated circuitry/memory, and the display  32  may be a liquid crystal display (LCD), although other suitable components or displays may also be used. While not shown in  FIG. 9 , the controller  31  may be carried by the PCB  30 , as will be appreciated by those skilled in the art. It should be noted that those components which are within the portable housing and not externally viewable are shown with dashed lines for clarity of illustration in  FIG. 9 . Moreover, while the satellite positioning antenna is illustratively at the bottom of the device  20  in  FIG. 9  also for clarity of illustration, this antenna may be positioned adjacent the top of the device (i.e., behind the display in the illustrated embodiment), as noted above. 
     When using the GPS function of the device  20  a user may hold the device in an upright position in which the display  32  is viewable to the user. In the exemplary embodiment, the controller  31  executes a mapping program which translates the positioning data received from the satellite positioning signal receiver  26  into location coordinates which are displayed at a corresponding location on a map, as will be readily appreciated by those skilled in the art. Thus, when the user holds the device  20  so that the display  32  faces him in the upright position, the PCB  30  serves as a reflector for directing the antenna beam pattern skyward for improved satellite positioning signal reception performance, as noted above. 
     The passive element  29  not only helps direct/shape the beam pattern in the desired direction, it may also provide desired antenna efficiency, as will be appreciated by those skilled in the art. By way of example, the performance of the  35 ′ illustrated in  FIG. 4  was tested at various frequencies and provided the results listed in Table 1 below. 
     
       
         
           
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 1565.42 MHZ 
                 1575.42 MHZ 
                 1585.42 MHZ 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 Average Gain 
                 −3.34526 dB 
                 −2.95445 dB 
                 −2.65694 dB 
               
               
                   
               
            
           
         
       
     
     As noted above, the dielectric extension  33  and antenna  35  are advantageously positioned adjacent an upper portion or top of the portable housing  21  to advantageously direct or shape the beam pattern skyward when a user holds the device  20  so that he can see the display  32 , as will be appreciated by those skilled in the art. Moreover, this allows the cellular (or other wireless) antenna  23  to be carried adjacent the bottom portion of the portable housing  21 , as schematically illustrated in  FIG. 2 . This not only provides for reduced interference between the two antennas, but it may also help with specific absorption ratio (SAR) compliance by moving the cellular antenna  23  further away from a user&#39;s brain when he places the input audio transducer of the device  20  (not shown) adjacent his ear, as will also be appreciated by those skilled in the art. 
     A method aspect of the invention is for making the mobile wireless communications device  20  and may include positioning a satellite positioning signal receiver  26  and at least one wireless transceiver  22  in a portable housing  21 , and connecting an active element  27  of a satellite positioning antenna  35  and carried by the portable housing to the satellite positioning signal receiver. The method may further include positioning a passive element  29  of the satellite positioning antenna  35  connected to a voltage reference (e.g., ground) in spaced apart relation from the active element  27  and operatively coupled thereto for directing a beam pattern thereof, as discussed further above. 
     Advantages of the above-described satellite positioning antenna structure may include allowing for downsizing of an overall antenna design where implementation area is relatively small. Moreover, the antenna structure provides for an effective use of the device&#39;s PCB board to improve efficiency. In addition, the antenna structure accommodates numerous geometries to thereby provide flexibility of implementation. 
     Additional features and components of a mobile wireless communication device in accordance with the present invention will be further understood with reference to  FIG. 10 . The device  1000  includes a housing  1200 , a keyboard  1400  and an output device  1600 . The output device shown is a display  1600 , which is preferably a full graphic LCD. Other types of output devices may alternatively be utilized. A processing device  1800  is contained within the housing  1200  and is coupled between the keyboard  1400  and the display  1600 . The processing device  1800  controls the operation of the display  1600 , as well as the overall operation of the mobile device  1000 , in response to actuation of keys on the keyboard  1400  by the user. 
     The housing  1200  may be elongated vertically, or may take on other sizes and shapes (including clamshell housing structures). The keyboard may include a mode selection key, or other hardware or software for switching between text entry and telephony entry. 
     In addition to the processing device  1800 , other parts of the mobile device  1000  are shown schematically in  FIG. 10 . These include a communications subsystem  1001 ; a short-range communications subsystem  1020 ; the keyboard  1400  and the display  1600 , along with other input/output devices  1060 ,  1080 ,  1100  and  1120 ; as well as memory devices  1160 ,  1180  and various other device subsystems  1201 . The mobile device  1000  is preferably a two-way RF communications device having voice and data communications capabilities. In addition, the mobile device  1000  preferably has the capability to communicate with other computer systems via the Internet. 
     Operating system software executed by the processing device  1800  is preferably stored in a persistent store, such as the flash memory  1160 , but may be stored in other types of memory devices, such as a read only memory (ROM) or similar storage element. In addition, system software, specific device applications, or parts thereof, may be temporarily loaded into a volatile store, such as the random access memory (RAM)  1180 . Communications signals received by the mobile device may also be stored in the RAM  1180 . 
     The processing device  1800 , in addition to its operating system functions, enables execution of software applications  1300 A- 1300 N on the device  1000 . A predetermined set of applications that control basic device operations, such as data and voice communications  1300 A and  1300 B, may be installed on the device  1000  during manufacture. In addition, a personal information manager (PIM) application may be installed during manufacture. The PIM is preferably capable of organizing and managing data items, such as e-mail, calendar events, voice mails, appointments, and task items. The PIM application is also preferably capable of sending and receiving data items via a wireless network  1401 . Preferably, the PIM data items are seamlessly integrated, synchronized and updated via the wireless network  1401  with the device user&#39;s corresponding data items stored or associated with a host computer system. 
     Communication functions, including data and voice communications, are performed through the communications subsystem  1001 , and possibly through the short-range communications subsystem. The communications subsystem  1001  includes a receiver  1500 , a transmitter  1520 , and one or more antennas  1540  and  1560 . In addition, the communications subsystem  1001  also includes a processing module, such as a digital signal processor (DSP)  1580 , and local oscillators (LOs)  1601 . The specific design and implementation of the communications subsystem  1001  is dependent upon the communications network in which the mobile device  1000  is intended to operate. For example, a mobile device  1000  may include a communications subsystem  1001  designed to operate with the Mobitex™, Data TAC™ or General Packet Radio Service (GPRS) mobile data communications networks, and also designed to operate with any of a variety of voice communications networks, such as AMPS, TDMA, CDMA, PCS, GSM, etc. Other types of data and voice networks, both separate and integrated, may also be utilized with the mobile device  1000 . 
     Network access requirements vary depending upon the type of communication system. For example, in the Mobitex and DataTAC networks, mobile devices are registered on the network using a unique personal identification number or PIN associated with each device. In GPRS networks, however, network access is associated with a subscriber or user of a device. A GPRS device therefore requires a subscriber identity module, commonly referred to as a SIM card, in order to operate on a GPRS network. 
     When required network registration or activation procedures have been completed, the mobile device  1000  may send and receive communications signals over the communication network  1401 . Signals received from the communications network  1401  by the antenna  1540  are routed to the receiver  1500 , which provides for signal amplification, frequency down conversion, filtering, channel selection, etc., and may also provide analog to digital conversion. Analog-to-digital conversion of the received signal allows the DSP  1580  to perform more complex communications functions, such as demodulation and decoding. In a similar manner, signals to be transmitted to the network  1401  are processed (e.g. modulated and encoded) by the DSP  1580  and are then provided to the transmitter  1520  for digital to analog conversion, frequency up conversion, filtering, amplification and transmission to the communication network  1401  (or networks) via the antenna  1560 . 
     In addition to processing communications signals, the DSP  1580  provides for control of the receiver  1500  and the transmitter  1520 . For example, gains applied to communications signals in the receiver  1500  and transmitter  1520  may be adaptively controlled through automatic gain control algorithms implemented in the DSP  1580 . 
     In a data communications mode, a received signal, such as a text message or web page download, is processed by the communications subsystem  1001  and is input to the processing device  1800 . The received signal is then further processed by the processing device  1800  for an output to the display  1600 , or alternatively to some other auxiliary I/O device  1060 . A device user may also compose data items, such as e-mail messages, using the keyboard  1400  and/or some other auxiliary I/O device  1060 , such as a touchpad, a rocker switch, a thumb-wheel, or some other type of input device. The composed data items may then be transmitted over the communications network  1401  via the communications subsystem  1001 . 
     In a voice communications mode, overall operation of the device is substantially similar to the data communications mode, except that received signals are output to a speaker  1100 , and signals for transmission are generated by a microphone  1120 . Alternative voice or audio I/O subsystems, such as a voice message recording subsystem, may also be implemented on the device  1000 . In addition, the display  1600  may also be utilized in voice communications mode, for example to display the identity of a calling party, the duration of a voice call, or other voice call related information. 
     The short-range communications subsystem enables communication between the mobile device  1000  and other proximate systems or devices, which need not necessarily be similar devices. For example, the short-range communications subsystem may include an infrared device and associated circuits and components, or a Bluetooth communications module to provide for communication with similarly-enabled systems and devices. 
     Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included within the scope of the appended claims.