Abstract:
A portable radiotelephone includes a transceiver, a processor, a speaker, a microphone, and a patch antenna. The transceiver transmits and receives radiotelephone communications, and the processor processes the radiotelephone communications transmitted and received by the transceiver. The speaker generates sound responsive to the received radiotelephone communications, the microphone generates electrical signals for the transmitted radiotelephone communications responsive to outside sound, and the patch antenna includes a conductive layer coupled to at least one of the processor and the transceiver. More particularly, the patch antenna can be a global position patch antenna that receives electromagnetic global position signals from a global position satellite.

Description:
FIELD OF THE INVENTION 
     The present invention relates to the field of communications and more particularly to radiotelephone communications. 
     BACKGROUND OF THE INVENTION 
     It has been proposed to provide global positioning features in cellular radiotelephones. For example, U.S. Pat. No. 5,235,633 to Dennison et al. discusses a cellular telephone system that uses the position of a mobile unit to make call management decisions. In particular, each mobile unit includes a global positioning system (GPS) receiver that receives information from a constellation of satellites to determine the precise location of the mobile unit. This position information is relayed to the cell site initially managing the mobile unit, and the mobile unit is handed off to a cell site that is most appropriate for the call. 
     In addition, U.S. Pat. No. 5,625,668 to Loomis et al. discusses a positioning reporting cellular telephone. The cellular telephone of this patent includes a global positioning system (GPS) receiver and a cellular transceiver. In addition, a data processing facility converts latitude, longitude, velocity, and bearing information provided by the GPS receiver into meaningful descriptors that are spoken with a speech synthesizer. The disclosures of both of these patents are hereby incorporated herein in their entirety by reference. 
     Portable radiotelephones including GPS receivers have typically used an additional antenna to provide GPS reception. For example, quadrafilar helix antennas extending from the radiotelephone body have been used. The size constraints on these antennas, however, may reduce the gain available using quadrafilar helix antennas. Moreover, these antennas may be oriented at less than ideal angles and/or may be too close to the user&#39;s body when used during telephone communications further reducing gain. Accordingly, there continues to exist a need in the art for improved antennas for GPS receivers incorporated into radiotelephones. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide improved antennas for cellular radiotelephones. 
     It is another object of the present invention to provide improved antennas for cellular radiotelephones including GPS receivers. 
     These and other objects are provided according to the present invention by a radiotelephone including a patch antenna including a conductive layer for receiving electromagnetic signals. In particular, the patch antenna can be used to receive global position signals in a radiotelephone including global position (GPS) features. Accordingly, the patch antenna can be included in/on the radiotelephone body without significantly affecting the dimensions thereof. 
     In the past, patch antennas have not generally been used in portable radiotelephones because the vertical orientation of the radiotelephone against the user&#39;s head, as occurs during normal radiotelephone use, is not desirable for patch antenna reception and gain. The inventors have realized, however, that a patch antenna can be used advantageously during radiotelephone GPS operations because the radiotelephone can be held horizontally away from the user&#39;s head. Moreover, the patch antenna can be added to the radiotelephone without significantly affecting the dimensions of the radiotelephone because the patch antenna can be incorporated substantially parallel to a face of the radiotelephone body. 
     In particular, a portable radiotelephone according to the present invention can include a transceiver, a processor, a speaker, a microphone, and a patch antenna. The transceiver transmits and receives radiotelephone communications, and the processor processes the radiotelephone communications transmitted and received by the transceiver. The speaker generates sound responsive to the received radiotelephone communications, and the microphone generates electrical signals for the transmitted radiotelephone communications responsive to outside sound. The patch antenna includes a conductive layer coupled to at least one of the processor and the transceiver. 
     More particularly, the patch antenna can be a global position patch antenna that receives electromagnetic global position signals from global position satellites, and the processor can include a global position receiver that determines a position of the radiotelephone based on the received electromagnetic global position signals. 
     The portable radiotelephone can include a radiotelephone body housing the speaker, the microphone, the transceiver, and the processor. In addition, an opening can be provided through the radiotelephone body adjacent the speaker to allow the generated sound from the speaker to pass therethrough, and the patch antenna can be located adjacent the speaker with an opening therein aligned with the opening in the face of the radiotelephone body to allow the generated sound from the speaker to pass therethrough. 
     Alternately, the patch antenna can have an opening therein aligned with another opening in the radiotelephone body to allow outside sound to pass through to the microphone. According to another alternative, the patch antenna can be adjacent to a keypad and have an opening therein aligned to allow a key of the keypad to move therethrough. 
     The radiotelephone can also include a display coupled to the processor wherein the processor generates a message on the display during global position calculations to encourage a horizontal orientation of the patch antenna. For example, the display might instruct the user to wait with the radiotelephone in a horizontal position held away from the user&#39;s body until the global position calculations have been completed. 
     The patch antenna can be provided, for example, by a conductive layer on a dielectric substrate inside the radiotelephone body. Alternately, the conductive layer can be provided on a surface of the radiotelephone body thereby eliminating the need for a separate dielectric layer. In other words, the radiotelephone body can be formed of a plastic that does not significantly attenuate the global position signals received from the global position satellites, and the conductive layer of the patch antenna can be formed as a part of the radiotelephone body. Furthermore, the conductive layer can be formed on either an inside or outside surface of the radiotelephone body. Furthermore, the patch antenna can be provided on a flip portion of the radiotelephone body. 
     The radiotelephones, and methods of the present invention can thus be used to provide a global position antenna within a portable radiotelephone without significantly affecting the dimensions of the radiotelephone. The radiotelephones, and methods of the present invention can also provide improved reception of GPS signals. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram of a radiotelephone including a patch antenna according to the present invention. 
     FIG. 2A is a perspective view of a radiotelephone including a patch antenna adjacent to a speaker according to the present invention. 
     FIGS. 2B-C are cross sectional views of alternate patch antenna structures for the patch antenna of FIG.  2 A. 
     FIG. 3A is a perspective view of a radiotelephone including a patch antenna adjacent to a keypad according to the present invention. 
     FIGS. 3B-C are cross sectional views of alternate patch antenna structures for the patch antenna of FIG.  3 A. 
     FIG. 4A is a perspective view of a radiotelephone including a patch antenna on a flip portion according to the present invention. 
     FIGS. 4B-C re cross sectional views of alternate patch antenna structures for the patch antenna of FIG.  4 A. 
    
    
     DETAILED DESCRIPTION 
     The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and 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, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the thicknesses of layers and regions of the cross sections are exaggerated for clarity. Like numbers refer to like elements throughout. It will also be understood that when a layer is referred to as being “on” another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present. 
     A cellular radiotelephone including a global positioning system (GPS) receiver according to the present invention is illustrated in FIG.  1 . As shown, the cellular radiotelephone includes a transceiver  21  for transmitting and receiving cellular radiotelephone communications through antenna  23 , and a processor  25  for processing the communications transmitted and received by the transceiver  21 . In addition, a user interface  27  is coupled with the processor, and the user interface can include a keypad  29 , a display  31 , a microphone  33 , and a speaker  35 . Accordingly, the radiotelephone can accept user speech through the microphone  33  for transmission to a radiotelephone communications system, and reproduce speech received from a distant party over the radiotelephone communications system using the speaker  35 . Radiotelephone information can be provided to the user through the display  31 , and user input can be accepted through the keypad  29 . 
     In addition, the radiotelephone of the present invention includes a GPS receiver  37  and a GPS patch antenna  39 . The GPS receiver  37  can thus accurately determine the geographic position of the radiotelephone, and provide the geographic information to the radiotelephone processor  25 . Accordingly, this geographic information can be provided to the radiotelephone user either visually through the display  31  or audibly through the speaker  35 . The geographic information can also be transmitted through the transceiver  21  and the antenna  23  to the radiotelephone communications system. For example, the geographic information can be transmitted during a “ 911 ” call to assist an emergency response by police, fire, and/or rescue personnel. The geographic information can also be used, for example, to make call management decisions as discussed in U.S. Pat. No. 5,235,633, spoken with a speech synthesizer as discussed in U.S. Pat. No. 5,625,668, or otherwise communicated to the user of the radiotelephone. 
     As will be understood by those having skill in the art, the GPS receiver  37 , the transceiver  21 , and the processor  25  can be provided separately as shown in FIG.  1 . Alternately, two or more of these elements can be provided together. For example, the processor can be defined as including one or both of the GPS receiver and the transceiver, and/or the transceiver can be defined as including the GPS receiver. These elements are shown separately for the sake of clarity of this disclosure and not for purposes of limitation. Moreover, these elements can be provided individually or in combination as one or more custom and/or standard integrated circuit and/or discrete devices running firmware and/or software. 
     The radiotelephone of the present invention can include the GPS patch antenna without significantly affecting the dimensions of the radiotelephone. As shown in FIG. 2A, the radiotelephone includes a body  41  housing the GPS patch antenna  39 A, the display  31 , the keypad  29 , the microphone  33 , and the antenna  23  as shown. In particular, the GPS patch antenna can include a conductive layer, such as a metal layer on a dielectric layer, wherein the conductive layer is approximately 1.0 inch square and the metal layer and the dielectric layer together have a thickness of approximately 0.2 inches. The housing also encloses the GPS receiver  37 , the transceiver  21 , the processor  25 , and the speaker  35  which are not visible in the perspective view of FIG.  2 A. 
     The radiotelephone body includes a front face  43  which is held to the user&#39;s head when talking. Accordingly, the speaker  35  is mounted adjacent the front face  43 , and holes  45  are provided in the front face adjacent the speaker to allow sound from the speaker to pass therethrough. Moreover, the microphone can be provided adjacent the front face with holes  47  being provided through the front face to allow sound to pass through to the microphone. 
     More particularly, the radiotelephone body of FIG. 2A includes a moveable flip portion  49  which extends the front face  43  when opened as shown, and the microphone  33  can be included in the main portion of the radiotelephone body. A channel  51  through the flip portion  49  can be used to conduct sound from the holes  47  to the microphone  33 . When closed, the flip portion  49  covers a portion of the radiotelephone body. The front face of the radiotelephone body can also include the display  31  and the keypad  29 . Accordingly, the flip portion  49  can cover the keypad and/or the display when closed. 
     According to the present invention, the patch antenna  39 A includes a conductive layer substantially parallel to the front face of the radiotelephone body. With dimensions of approximately 1.0 inches square and 0.2 inches thick, the patch antenna can be incorporated in the radiotelephone of the present invention without significantly affecting the dimensions of the radiotelephone. As shown in FIG. 2A, the patch antenna can be located adjacent the speaker with openings therein aligned with the openings  45  in the front face of the radiotelephone body to allow sound to pass therethrough. These relatively small openings (or holes) in the patch antenna can be provided without significantly affecting the antenna performance. Furthermore, the antenna can be tuned to compensate for the addition of these holes. Alternate arrangements of the patch antenna  39 A are illustrated in the cross sections of FIGS. 2B-2C. 
     In FIG. 2B, the patch antenna includes a conductive layer  53  on a dielectric layer  55  mounted between the speaker  35  and the front face  43  of the radiotelephone body. As shown, the openings  45  extend through the front face  43  of the radiotelephone body, the conductive antenna layer  53 , the dielectric layer  55 , and conductive ground layer  56 . Accordingly, a conventional patch antenna can be used without significantly affecting the dimensions of the radiotelephone. Preferably, the front face of the radiotelephone body is formed from a plastic or other material which does not significantly attenuate the GPS signals (typically 1575.42 MHz) received by the patch antenna. A typical connection to a patch antenna is made with coaxial cable  58 . The center conductor of  58  electrically connects to conductive antenna layer  53  and the ground shield of  58  electrically connects to conductive ground layer  56 . It is usually good practice (but not necessary) to make the ground layer  56  of the patch as large as is convenient. The exact size and shape of layer  53  tunes the antenna. The exact placement of the connection between the patch antenna and coaxial cable  58  determines impedance matching and antenna polarization. 
     Accordingly to another alternative, shown in FIG. 2C, the patch antenna can include a conductive antenna layer  53 ″ formed on the outside surface of the front face of the radiotelephone body opposite the speaker  35 . In addition, a protective layer  57  can be formed on the conductive antenna layer  53 ″ to reduce wear of the conductive layer. Here, the openings  45  extend through the protective layer  57 , the conductive antenna layer  53 ″, the front face  43 , and conductive ground layer  56 ″, allowing sound from the speaker to pass therethrough. The material and thickness of front face  43  should be consistent with the electrical characteristics of a patch antenna. The dielectric constant and thickness affect the size of layer  53 ″ and the useable bandwidth of the antenna. 
     The GPS patch antenna  39 A discussed above is thus oriented substantially parallel to the front face of the radiotelephone body. Accordingly, the radiotelephone is preferably held with the front face substantially parallel to the ground when receiving GPS signals from GPS satellites. This orientation can provide a circular polarization for the patch antenna that matches the circular polarization of signals transmitted by the GPS satellites. This orientation can be facilitated during GPS operations using messages on the display  31 . For example, the processor can generate explicit instructions on the display to hold the telephone in the desired orientation (front face up and away from the user&#39;s body) while the location is being determined. 
     Alternately, this orientation can be encouraged more subtly so that the user is less likely to notice the delay of determining the location. In particular, the processor can generate any message on the display that will hold the user&#39;s attention. Because the phone is held in approximately the desired orientation when the user is reading the display, the patch antenna can receive the GPS signals used for location determination. Once the location has been determined, the processor can generate a message on the display instructing the user to continue with normal operations. 
     An alternate arrangement of the patch antenna  39 B is illustrated in FIG.  3 A. In FIG. 3A, the patch antenna  39 B provided adjacent the keypad  29  including a plurality of keys  29   a , key contacts  29   b , PC board substrate  29   c , and openings are provided through the front face  43  of the radiotelephone body and the patch antenna  39 B to allow movement of the keys  29   a  therethrough and to allow contact between the keys  29   a  and the key contacts  29   b  inside the radiotelephone body. As before, the radiotelephone also includes an antenna  23 , openings  45  in the radiotelephone body allowing sound from the speaker to pass therethrough, a display  31 , a microphone  33 , a flip portion  49 , and openings  47  and channel  51  allowing passage of sound to the microphone. Various patch antenna structures for patch antenna  39 B are illustrated in FIGS. 3B-C. 
     As shown in FIG. 3B, the patch antenna  39 B can include a conductive antenna layer  63  on a dielectric layer  65 , along with conductive ground layer  64  and coaxial cable  58  attached to layers  63  and  64 , and the patch antenna can be mounted along the inside surface of the front face  43  of the radiotelephone body adjacent the keypad  29  including keys  29   a . Openings through the front face  43 , the conductive layer  63 , the dielectric layer  65 , and the ground layer  64  provide movement of the keys  29   a  therethrough as well as contact between the keys and the keypad PC board substrate  29   c . The ground layer  64  of the patch antenna can be disrupted by keypad contacts. (and traces)  29   b  with little impact. The center conductor of coaxial cable  58  connects to layer  63  and the shield of cable  58  connects to layer  64 . 
     According to another alternative, the conductive layer  63 ″ can be formed on the outside surface of the front face  43  of the radiotelephone body as shown in FIG.  3 C. In particular, the conductive layer  63 ″ can be formed on the outside surface of the front face, and a protective layer  67  can be formed on the conductive layer  63 ″ . Openings through the front face, the conductive layer, the protective layer, and the conductive ground layer  64 ″ provide for movement of the keys  29   a  and/or keypad contacts  29   b  therethrough. 
     Another alternate arrangement of the patch antenna  39 C is illustrated in FIG.  4 A. In FIG. 4A, the patch antenna  39 C is provided on the flip portion  49  of the front face of the radiotelephone body, and openings are provided through the patch antenna  39 C to allow passage of sound therethrough to the microphone  33 . As before, the radiotelephone also includes an antenna  23 , openings  45  in the radiotelephone body allowing sound from the speaker to pass therethrough, a display  31 , a microphone  33 , a flip portion  49 , and openings  47  and channel  51  allowing passage of sound to the microphone. Various patch antenna structures for patch antenna  39 C are illustrated in the cross sectional views of FIGS. 4B-C. 
     As shown in FIG. 4B, the patch antenna  39 C can include a conductive antenna layer  73 , a dielectric layer  75 , and a conductive ground layer  76  adjacent the front face of the flip portion  49  of the radiotelephone body. Moreover, the openings  47  extend through the front face  43 , the conductive layer  73 , the dielectric layer  75 , and conductive ground layer  76  allowing the conduction of sound therethrough to the channel  51  and the microphone  33 . The electrical connection to patch antenna  39   c  is via coaxial cable  58 . The center conductor of cable  58  connects to layer  73  and the shield of  58  connects to layer  76 . Cable  58  can be routed physically in cavity  51 . 
     As shown in FIG. 4C, the conductive layers  73 ″ and  76 ″ along with dielectric layer  75  can be formed on the surface of the front face of the flip portion, and a protective layer  77  can be formed on the conductive layer. Again, the openings  47  through the protective layer  77 , the conductive layers.  73 ″ and  76 ″ and dielectric layer  75 , and the front face of the flip portion allow conduction of sound therethrough to the channel  51  and the microphone  33 . 
     In each of the patch antennas discussed above, the patch antenna can be provided without significantly affecting the dimensions of the radiotelephone. Moreover, holes in the patch antenna allow placement of the antenna adjacent the speaker, the microphone, or the keypad, and any affect of the holes on the performance of the patch antenna can be reduced by tuning the antenna. In addition, the patch antenna in the radiotelephone can provide circular polarization matching that of GPS signals transmitted by GPS satellites. The patch antenna of the present invention can thus provide improved performance over GPS antennas previously used in radiotelephones including GPS functions. 
     In the drawings and specification, there have been disclosed typical preferred embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth in the following claims. Furthermore, while radiotelephones including patch antennas according to the present invention have been discussed with reference to cellular radiotelephones, the patch antennas of the present invention can be used with other radiotelephones such as satellite radiotelephones or dual mode radiotelephones capable of communicating with terrestrial and satellite communications systems, as well as radiotelephones capable of communicating with other types of terrestrial communications systems.