Abstract:
A portable, self contained, dual frequency external antenna configuration is provided for use with a phone, such as a cell phone having either an outwardly extending antenna or an internal antenna to enhance cell phone operation. The antenna configuration comprises a first antenna tuned to a first cell phone operating frequency and a second antenna tuned to a second cell phone operating frequency. A connector is provided, the connector adapted for making a connection to the cell phone and at least one transmission line connects the first and second antennas to the connector.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation-in-part of U.S. patent application Ser. No. 11/233,908 filed Sep. 23, 2005 and entitled “Personal Portable External Cell Phone Antenna”, now abandoned. This application claims the benefit of U.S. Provisional Patent Applications Nos. 60/643,377 filed Jan. 13, 2005; 60/650,581 filed Feb. 7, 2005; and 60/654,880 filed Feb. 22, 2005, the subject matter of each of which is hereby incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     This invention relates to a portable, self contained device which incorporates patterns of electrically conductive lines in the configuration of one or more antennas tuned to one or more of the operating frequencies of a cell phone which, when connected to the cell phone, enhances the performance of the cell phone.  
         [0003]     The need for reliable wireless communication essentially gave rise to two different ways of achieving this result. One such system utilized a set of low earth orbiting satellites and hand held transceivers. This system provided very highly reliable communication, but was too expensive to operate, the hand held devices were too large and expensive, and the two systems, Iridium and Globalstar filed for bankruptcy. The other system, utilizing small hand held devices that transmitted to a local antenna tower, outperformed the satellite systems in terms of size, cost and versatility. Now, only small hand held cell phones are in common use and antenna towers dot the landscape in order to provide the needed signal-to-noise ratio [S/N] for clear static free communication. The competition between the various suppliers of cell phones has resulted in cell phones becoming smaller and smaller. As size was reduced, the antenna attached to the cell phone also became smaller. To compensate for such smaller antennas, the power generated within the cell phone has been increasing. This trend has resulted in temperatures inside some cell phones becoming high enough to overheat the cell phone batteries, which have been reported exploding. There is a need to increase the Effective Radiated Power [ERP] of a small cell phone so that the RF power generated within the cell phones can be minimized and personal safety increased. The solution is to increase the effectiveness of the antenna system for the cell phone.  
         [0004]     Presently there are many external antennas for sale for just this purpose. A visit to the web site AlternativeWireless.com shows many antennas for sale that will improve the reception of a cellular phone. Wilson Electronics is a manufacturer of many models of such antennas. Some of these antennas are described in U.S. Pat. Nos. 6,788,261, 6,486,840 and 6,317,089 assigned to Wilson Electronics, Inc. and U.S. Pat. No. 6,714,164 assigned to Nippon Antenna Kabushiki Kaisha. These antennas are not intended to be carried around. There are numerous models for mounting on a vehicle or being placed upon a metallic surface in a home or office to improve operation. One such antenna is the “Wilson Mini Dual Band Magnetic Mount Antenna”. All these antennas have one characteristic in common. They are only 1 of the antenna. They rely on being mounted on a fairly large metallic surface in order to create an image below the metallic surface, thereby creating a virtual entire antenna structure tuned to the cell phone frequencies of operation. However, there are no portable antennas being offered for sale to significantly improve the performance of the cell phone of the average user that operate without the need for such a metallic surface.  
         [0005]     A visit to the Factory Direct Cellular web site reveals three small antennas that claim to provide some improvement in cell phone reception. One such device is called a “cellular Antenna Booster” that fits inside a cell phone case and claims to provide some improvement. The other devices shown are designed to attempt to transfer signals from inside a vehicle to the outside, thereby providing some measure of improvement. However, until now, there are no practical portable antennas that provide significant improvement in cell phone reception. Such an antenna must be easy to carry around and easy to connect to the cell phone when improved performance is desired/required.  
         [0006]     The present invention solves this problem by incorporating one or more full ½ wave dipole antennas into a small assembly that can be attached to a cell phone so that the user has the advantage of an external antenna to enhance the operation of the cell phone without the cumbersome problem of carrying around a bulky external antenna that must be mounted on a metallic surface in order to be utilized. Without an external antenna, a cell phone increases the RF energy generated within the cell phone in order to achieve a secure link to a nearby tower. If a secure link to the tower cannot be achieved, the call is lost. Use of an external antenna increases the probability of achieving a secure link to a tower, thereby allowing the call to be completed, as well as minimizing the RF energy generated within the cell phone, thereby diminishing any health risks associated with holding a cell phone directly to one&#39;s head. The present invention is the first use of such technology to enhance cell phone performance. Several field trials utilizing an embodiment of the present invention have been conducted. Reliable reception was achieved in places where in the absence of the present invention no service was obtainable, notably in the mountains in New Hampshire, on the beach in Southern New Jersey, in the mountains north of San Francisco, and in the vehicle of a traveling salesman, who claims to have, for the first time, never lost a call while traveling.  
         [0007]     There are several reasons why one skilled in the antenna art has not come up with an antenna configuration similar to the present invention. The existing antenna on a cell phone is obviously inadequate to provide a high gain link to a remote tower. So it was obvious that it made sense to bypass this antenna by connecting directly to the circuitry inside the phone, either via a coaxial connection provided by the manufacturer or by removing the cell phone antenna and plugging in a well-designed external antenna. Regarding the design of an external antenna, it was “obvious” that an omni-directional radiation pattern would be ideal since one does not know the direction to the nearest tower. Then there is the problem that the antenna must cover two separate frequency bands, separated by more than a 2:1 ratio. There are numerous classical methods of combining two frequency bands such as these into a single omni-directional configuration. It is complicated, but has been done for a long time. Once one has a dual frequency omni directional antenna in mind, utilizing a metallic ground plane to eliminate the need to fabricate the entire dipole structure appeared apparent, especially when it was the customer who had to supply the ground plane. Finally, there was the unknown effect of the human body on the operation of an antenna in close proximity. For these various reasons, external antennas currently for sale to the public are omni-directional and plug into the phone. The fact that each model phone requires a different type connection and that the customer must provide a metallic ground plane beneath the antenna are factors that the designers of external cell phone antennas felt they just had to live with.  
         [0008]     A portable external cell phone antenna in accordance with the present invention includes a small dual frequency antenna and a means to make a connection to a cell phone. The antenna incorporates a number of narrow lines capable of conducting an electrical signal. The configuration of the conductive lines forms an antenna or array of antennas which is tuned to the frequency or frequencies of cell phone operation. According to a particularly advantageous aspect of the invention, a means is provided to wirelessly couple the present antenna to the existing antenna of a cell phone. In another particularly advantageous aspect of the invention, a means is provided to reduce the size of the antenna assembly to make it convenient to carry it on one&#39;s person. Use of the present invention enhances the performance of a cell phone and increases personal safety by minimizing the RF power generated within said cell phone.  
         [0009]     Antennas tuned to the frequency of operation of a cell phone [806-894 MHz, referred to as the 850 MHz band, and 1850-1990 MHz, referred to as the 1950 MHz band, or some other frequency of operation] are incorporated in a small assembly. The assembly incorporates a means for the antennas to be connected to a cell phone. The user connects the assembly to a cell phone in order to improve the performance of the cell phone. In the preferred embodiment of the invention, the antenna couples directly to the cell phone antenna, thereby making it a more universal type connection, not depending upon the different means of making a direct connection to the various models of cell phones currently on the market. The present invention enhances signals in what is called the “quad-band” which includes the frequencies of 850, 900, 1800 and 1900 MHz.  
       BRIEF SUMMARY OF THE INVENTION  
       [0010]     Briefly stated, in one embodiment, the present invention comprises a portable, self contained, dual frequency external antenna configuration for use with a phone, such as a cell phone to enhance cell phone operation. The antenna configuration comprises a first antenna tuned to a first cell phone operating frequency and a second antenna tuned to a second cell phone operating frequency. A connector is provided, the connector being adapted for making a connection to the cell phone and at least one transmission line connects the first and second antennas to the connector.  
         [0011]     In another embodiment the present invention comprises a portable, self contained, external antenna configuration for use with a phone, such as a cell phone to enhance cell phone operation. The antenna configuration comprises at least a first antenna tuned to a cell phone operating frequency and a connector adapted for making a connection to the cell phone. At least one transmission line connects the first antenna to the connector. 
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0012]     The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.  
         [0013]     In the drawings:  
         [0014]      FIG. 1  is a simplified pictorial of a cell phone showing a typical cell phone external antenna;  
         [0015]      FIG. 2  is a detailed pictorial of an 850 MHz antenna combined with a 1950 MHz antenna according to a preferred embodiment of the present invention;  
         [0016]      FIG. 3  shows the antenna of  FIG. 2  connected to a multiple loop connector coil via a two wire transmission line;  
         [0017]      FIG. 4  shows the antenna configuration of  FIG. 3  connected to a cell phone antenna in a wireless manner, according to one embodiment of the present invention;  
         [0018]      FIG. 5  shows the antenna configuration of  FIG. 3  connected to a cell phone antenna, according to one embodiment of the present invention where the antenna is configured as a printed circuit;  
         [0019]      FIGS. 6A and 6B  show the antenna configuration of  FIG. 3  compressed and inserted into a container according to one embodiment of the invention;  
         [0020]      FIG. 7  shows an alternate embodiment of the antenna configuration of  FIG. 3  wherein the antenna and the coil are constructed as flat strips;  
         [0021]      FIG. 8  shows a preferred embodiment of the antenna assembly of  FIG. 7  wherein the antenna and connector coil are a printed circuit on a non-metallic material;  
         [0022]      FIG. 9  shows the antenna configuration of  FIG. 8  connected to the external antenna of a cell phone;  
         [0023]      FIG. 10  shows the antenna configuration of  FIGS. 6A and 6B  connected to a cell phone in one embodiment of the invention;  
         [0024]      FIGS. 11A and 11B  show a simplified pictorial of a cell phone employing an internal cell phone antenna;  
         [0025]      FIG. 12  shows the antenna configuration of  FIG. 7  where the antenna is configured as a printed circuit;  
         [0026]      FIGS. 13A, 13B ,  13 C,  13 D and  13 E show how the printed circuit antenna of  FIG. 12  can be folded so as to fit within the extremities of the cell phone shown in  FIG. 11 ;  
         [0027]      FIG. 14  shows the folded antenna configuration of  FIG. 13E  connected to the cell phone of  FIG. 11  in a wireless manner, according to one embodiment of the present invention;  
         [0028]      FIG. 15A  is a simplified pictorial showing a person holding a cell phone according to  FIG. 14  to his head according to one embodiment of the present invention;  
         [0029]      FIG. 15B  is a simplified pictorial showing a person holding a cell phone according to  FIG. 10  to his head according to a second embodiment of the present invention; and  
         [0030]      FIG. 15C  is a simplified pictorial showing a person holding a cell phone according to  FIG. 11  combined with the configuration of  FIG. 6  to his head according a third embodiment of the present invention; 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0031]     Referring to the drawings in detail, wherein like numerals indicate like elements throughout,  FIG. 1  shows a typical cell phone  12  with a typical external cell phone antenna  22 .  
         [0032]      FIG. 2  shows two different antennas  32  and  34 , arranged in an assembly  20  to provide greater cell phone performance enhancement than is available with a single frequency antenna. Antenna  32  is preferably tuned to the 850 MHz band and antenna  34  is preferably tuned to the 1950 MHz band. Dimensions d 2 , d 4  and d 2  when combined form a half wavelength [λ/2] in the 850 MHz band and dimension d 3  is a half wavelength [λ/2] in the 1950 MHz band. Since antenna  32  and antenna  34  operate at different cell phone frequencies, there is no phase relationship between them, except that dimension d 1  should preferably be as small as possible to realize the smallest possible overall size of the antenna configuration that incorporates the present invention. By setting dimension d 1  at approximately λ/4 at 1950 MHz, antenna  34  utilizes antenna  32  as a reflector, thereby increasing the gain of antenna  34  in the plane of the antenna assembly. The antennae are preferably made of metallic wire but some other material such as a printed circuit may be used. Preferably, two wire transmission lines  42  and  44  connect antennas  32  and  34  to transmission lines  36 ,  38  ( FIG. 3 ).  
         [0033]      FIG. 3  shows the antenna assembly  20 , connected to a multiple loop wireless connector  48  via transmission lines  36 ,  38 . The entire antenna assembly will be hereinafter referred to as antenna configuration  14 . The multiple loops of the wireless connector  48  are preferably made of insulated wire but some other material such as a printed circuit may be used. The transmission lines  36 ,  38  are also preferably made of wire but some other material such as a printed circuit may be used. The antenna assembly  20  may be connected to the cell phone  12  in some other manner if desired. For example, a coaxial connector (not shown) may be connected to the transmission lines  36 ,  38  for connection to a complementary coaxial connector (not shown) on the cell phone  12 . Alternatively, the external cell phone antenna  22  could be removable and a special connector (not shown) could be used to connect the antenna assembly  20  to the cell phone  12  where the cell phone antenna  22  had been connected. Other connectors and methods of connecting the antenna assembly  20  to a cell phone  12  will be apparent to those skilled in the art.  
         [0034]      FIG. 4  shows the antenna configuration  14  connected to cell phone  12  with the loops of the wireless connector  48  surrounding at least a portion of the cell phone external antenna  22 . In this manner, the antenna configuration  14  makes a wireless connection to the cell phone antenna  22 .  
         [0035]      FIG. 5  shows an antenna configuration  40  according to the present invention, mounted to the external antenna  22  of cell phone  12  via the loops of the wireless connector  48  and transmission line  36 ,  38 . Antenna configuration  40  is shown as a printed circuit  28  which incorporates the antenna configuration  20  of  FIG. 3 .  
         [0036]      FIGS. 6A and 6B  show one possible manner in which an external cell phone antenna in accordance with the present invention as described above can be packaged as antenna configuration  41  in a container or housing  16 . The dimensions of the container  16 , which in the present embodiment is generally cylindrically shaped, are shown as D 5  long and D 6  in diameter. Other container dimensions, shapes and configurations are within the spirit of the invention. Antenna configuration  41  is either folded, rolled or compressed in some manner in order for it to fit within the container  16 . Container  16  is small and is designed such that the user can carry it on their person, so that the cell phone antenna configuration  14 , according to the present invention, is readily available for use in any locality and at any time.  
         [0037]      FIG. 7  shows an antenna configuration  80  as a flat strip version of the antenna configuration  14  shown in  FIG. 3 .  
         [0038]      FIG. 8  shows an antenna configuration  82  fabricated as a printed circuit version of the antenna configuration  80  shown in  FIG. 7 . The slits  83   a  through  83   e  in the vicinity of the printed circuit coil allow the printed circuit coil to fit around an external cell phone antenna  22 . There may be a different number of slits and coils than shown without violating the spirit of the invention.  
         [0039]      FIG. 9  shows an antenna configuration  82  as a flat strip version of the antenna configuration  14  with the printer circuit coil surrounding at least a portion of the external antenna  22  of cell phone  12  for wirelessly connecting the antenna configuration  82  to the cell phone  12  according to the present invention.  
         [0040]      FIG. 10  shows the stored antenna configuration  41  of  FIGS. 6A and 6B  in the container  16  with the stored antenna configuration  41 , while still in the container  16 , connected to a cell phone  12  via the cell phone antenna  22 , (not shown).  
         [0041]      FIGS. 11A and 11B  show of a typical flip-type cell phone  130  comprising sections  124  and  140  with a typical internal cell phone antenna (not shown) located inside of section  124  and with no external cell phone antenna. It is recognized that there are one-piece cell phones with an internal antenna. All references to a flip-type cell phone applies equally to such one-piece cell phones.  
         [0042]      FIG. 12  shows an antenna configuration  132  which is similar to configuration  82  and has been fabricated as a printed circuit version of the antenna configuration  80  shown in  FIG. 7 . The slits  83   a  through  83   e  shown in  FIG. 8  are not needed in this version of the printed circuit coil. There may be a different number of coils than shown without violating the spirit of the invention.  
         [0043]      FIGS. 13A, 13B ,  13 C,  13 D and  13 E show how the printed circuit antenna configuration  132  can be folded along the dashed lines with sections  184 ,  186  and  188  overlying each other and with sections  190  and  192  overlying each other to produce a thin antenna configuration  200  that can be held against cell phone  130  to enhance the performance of cell phone  130 .  
         [0044]      FIG. 14  shows the folded antenna configuration  200  mounted to a cell phone  130  having an internal antenna.  
         [0045]      FIGS. 15A-15C  illustrates three ways that the present invention may be utilized to improve cell phone performance.  FIG. 15A  shows a user  10  holding a cell phone  130  which includes the thin folded antenna configuration  200 . This is one method, according to the present invention, of improving the performance of a cell phone  130  that incorporates an internal antenna.  FIG. 15B  shows a user  10  holding a cell phone  12  which includes antenna configuration  16 . This is a method, according to the present invention, of improving the performance of a cell phone  12  that incorporates an external antenna  22 .  FIG. 15C  shows a user  10  holding a cell phone  130  which utilizes antenna configuration  16 . This is a second method, according to the present invention, of improving the performance of a cell phone that incorporates an internal antenna.  
         [0046]      FIGS. 15A, 15B  and  15 C show several possible ways that an antenna configuration according to the present invention is intended to be utilized. Other ways to use the disclosed antenna configurations in accordance with the present invention will be apparent to those skilled in the art. The stored antenna configuration  41  shown in  FIGS. 6A and 6B  preferably has the size and shape of a pen so that it can be stored conveniently in a pocket or purse. This antenna configuration can be utilized with cell phones having either external or internal antennas. The antenna configuration  200  preferably has the size and shape of a credit card so that it can also be stored conveniently in a pocket or purse. This antenna configuration can be utilized with cell phones having an internal antenna.  
         [0047]     The use of an external antenna configuration according to the present invention is not intended solely for those geographic areas that cannot reliably connect to a cell tower for whatever reason. By utilizing an external antenna configuration according to the present invention in areas with a strong connection to a cell tower, the transmitter within the cell phone may reduce its RF power level making the cell phone less likely to cause health related problems.  
         [0048]     In the preferred embodiment of the invention, the following dimensions were selected:  
         [0049]     Dimension d 1 =3.0 inches  
         [0050]     Dimension d 2 =1.5 inches  
         [0051]     Dimension d 3 =3.5 inches  
         [0052]     Dimension d 4 =4.0 inches  
         [0053]     Dimension d 5 =6.0 inches  
         [0054]     Dimension d 6 =0.5 inches  
         [0055]     It will be recognized by those skilled in the art that changes may be made to the above described embodiments of the present invention without departing from the broad inventive concepts thereof. For example, the antenna connection to the cell phone may be made via a connector other than the coils which make a wireless connection. In addition, the configuration of the antenna assembly, shown as a generally planar assembly, may be changed to some other configuration while maintaining the portability aspect of the concept. Further, the antenna assembly  14  could be reconfigured and tuned to the frequency of a satellite radio, thus providing the user of such a service enhanced reception. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but is intended to cover all modifications to the particular configuration of an external cell phone antenna assembly or the means of connecting the antenna assembly electrically to the cell phone, which are within the scope and spirit of the invention as defined by the appended claims.