Abstract:
An antenna is provided for the new combined GPS and GLONASS technologies in single port for tracking and navigation applications in wireless devices. The resonant mechanism is excited by an open loop structure at 1.575 GHz and 1.610 GHz, forcing the current distribution to remain at that particular portion of the antenna resulting as the primary resonator.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation in part of U.S. Ser. No. 14/049,186, filed Oct. 8, 2013; 
     which claims benefit of priority with U.S. Provisional Ser. No. 61/711,191, filed Oct. 8, 2012; 
     the contents of each of which are hereby incorporated by reference. 
    
    
     BACKGROUND 
     1. Field of the Invention 
     This invention relates to antennas; and more particularly to antennas configured for operability among GPS and GLONASS platforms. 
     2. Description of the Related Art 
     Satellite based location services are provided by Global Positioning System (GPS) and Global Navigation Satellite System (GLONASS). 
     GLONASS began worldwide operation in October of 2011. As such, consumer level devices are being developed which make use of the GLONASS platform. 
     There is a need for GLONASS antennas for integration with forthcoming devices. 
     There is a further need for a GPS and GLONASS compatible antenna, capable of servicing both platforms for providing robust and selectable satellite based location services. 
     SUMMARY 
     An antenna is provided for the new combined GPS and GLONASS technologies in single port for tracking and navigation applications in wireless devices. The resonant mechanism is excited by an open loop structure at 1.575 GHz and 1.610 GHz, forcing the current distribution to remain at that particular portion of the antenna resulting as the primary resonator. 
     When a metallic element becomes in close proximity to the antenna, instead of being highly de-tuned, the antenna only suffers minor mismatching but continues to provide a working resonance at similar frequency. 
     The antenna design has a very low profile of 0.15 mm of total thickness. The antenna has a good immunity to resist detuning by nearby metal parts such as RF connectors, I/O connectors, metal shielding, batteries, proximity with human body and other high dielectric elements. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows and electromagnetic open loop antenna with a self-coupling element fixed on a flexible substrate. 
         FIG. 2  shows a conductor portion of the electromagnetic open loop antenna. 
         FIG. 3  further shows an expanded view of the conductor portion associated with the antenna. 
         FIG. 4  shows details of the antenna and structural elements thereof. 
         FIG. 5  shows a section view of the antenna illustrating multiple layers thereof. 
         FIG. 6  shows a plot of return loss associated with the antenna in one embodiment. 
         FIG. 7  shows a plot of efficiency associated with the antenna in one embodiment. 
         FIG. 8  shows peak gain associated with the antenna in one embodiment. 
         FIG. 9  shows electromagnetic fields concentrated within a primary radiating portion of the antenna for enhanced isolation from nearby components or human detuning effects. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     In various embodiments, an antenna is described that provides stable radiation performance across a wide bandwidth when mounted in difficult scenarios or use cases. 
     In one embodiment, an effective technique comprises implementing an open loop structure to force the current distribution to be kept and isolated mainly in that portion of the antenna referred to herein as a “channel”. 
     In certain embodiments, the electromagnetic fields of the antenna resist coupling with nearby positioned elements, since the fields are kept at the open loop structure, and as a result the antenna is substantially consistent in frequency and not shifted, or detuned. 
     Forming the antenna on flexible body allows the antenna to conform to a surface of the device where the antenna can be placed or bent multiple times. However, in other embodiments the antenna may alternatively be developed in a rigid form. 
     A coax-cable may be provided for simple connectivity. Alternatively, other type of connections may be implemented such as pogo pins, spring contacts, and the like. 
     In certain embodiments, slots are incorporated in the antenna design for a better response and improved tuning when needed. 
       FIG. 1  shows and electromagnetic open loop antenna with a self-coupling element fixed on a flexible substrate. 
     The antenna  100  is shown coupled to a coaxial cable  30  having a feed wire and a ground wire. The antenna comprises a monolithic conductor  20  disposed on a flexible polymer substrate  10 . 
       FIG. 2  shows a conductor portion of the electromagnetic open loop antenna. 
     The conductor comprises a rounded peripheral edge extending about an outer periphery of the conductor; a center portion having four sides; a rectangular feed pad  25  extending from a first side of the center portion; a corner portion disposed adjacent to the rectangular feed pad and forming a right-angle about the first side of the center portion and a second side thereof; a first conductor portion  22  extending from a third side of the center portion opposite of the first side; a second conductor portion  21  extending from a fourth side of the center portion opposite of the second side, said second conductor portion arranged to overlap with the rectangular feed pad and the corner portion, and further configured to overlap with an edge of the first conductor portion. A channel  23  extends about three sides of the rectangular feed pad  25  and outwardly through the peripheral edge, said channel further extending around the corner portion and separating the second conductor portion  21  from the first conductor portion  22 . A tuning slot  24  extends outwardly from the center portion to the peripheral edge, the tuning slot is disposed between the first and second conductor portions  21 ;  22 , respectively. 
       FIG. 3  further shows an expanded view of the conductor portion associated with the antenna. 
     The conductor portion further comprises a first isolated region  33  disposed between the second conductor portion and the rectangular feed pad; a gap  32  disposed between the corner portion and a diagonal edge; and a second isolated region  31  disposed along the channel between the first and second conductor portions. 
     The conductor additionally comprises a tuning slot having a first tuning region  35  extending from the center portion, and a second tuning region  34  extending from the first tuning region  35  to the periphery of the conductor. The second tuning region is oriented at an angle with respect to the first tuning region; the angle is less than ninety degrees. 
       FIG. 4  shows details of the antenna and structural elements thereof. 
     The antenna  100  comprises a monolithic planar conductor comprising: a rounded peripheral edge  55 ;  56  extending about an outer periphery of the conductor; a center portion  43  having four sides; a rectangular feed pad  25  extending from a first side of the center portion; a corner portion  57  disposed adjacent to the rectangular feed pad and forming a right-angle about the first side  52  of the center portion and a second side thereof; a first conductor portion and a first radiating portion  42  associated therewith extending from a third side of the center portion opposite of the first side; a second conductor portion and a second radiating portion  41  associated therewith extending from a fourth side of the center portion opposite of the second side, said second conductor portion arranged to overlap with the rectangular feed pad  25  and the corner portion  57 , and further configured to overlap with an edge of the first conductor portion  45 . The conductor further comprises a channel extending about three sides of the rectangular feed pad  25  and outwardly through the peripheral edge  56 , said channel further extending around the corner portion  57  and separating the second conductor portion  44  from the first conductor portion  45  at respective first and second edges thereof. A tuning slot extends outwardly from the center portion to the peripheral edge, the tuning slot being disposed between the first and second conductor portions. 
       FIG. 5  shows a section view of the antenna illustrating multiple layers thereof. 
     In an embodiment, from the bottom going upward through the cross section, the antenna comprises a liner  501 ; an adhesive layer  502 ; a bottom solder mask  503 ; a flexible polymer  504 ; a first conductor  505 , for example copper; a top solder mask  506 ; and a second conductor  507 , for example tin or gold. 
       FIG. 6  shows a plot of return loss associated with the antenna in one embodiment. 
       FIG. 7  shows a plot of efficiency associated with the antenna in one embodiment. 
       FIG. 8  shows peak gain associated with the antenna in one embodiment. 
       FIG. 9  shows electromagnetic fields concentrated within a primary radiating portion of the antenna for enhanced isolation from nearby components or human detuning effects. 
     LIST OF REFERENCE CHARACTERS 
     
         
         ( 10 ) flexible polymer substrate 
         ( 20 ) monolithic planar conductor 
         ( 21 ) second conductor portion 
         ( 22 ) first conductor portion 
         ( 23 ) channel 
         ( 24 ) tuning slot 
         ( 25 ) rectangular feed pad 
         ( 26 ) ground pad 
         ( 30 ) coaxial cable 
         ( 31 ) second isolated region 
         ( 32 ) gap 
         ( 33 ) first isolated region 
         ( 34 ) second tuning slot region 
         ( 35 ) first tuning slot region 
         ( 41 ) second radiating portion 
         ( 42 ) first radiating portion 
         ( 43 ) center portion 
         ( 44 ) first edge 
         ( 45 ) second edge 
         ( 52 ) first side of center portion 
         ( 53 ) diagonal edge 
         ( 54 ) opposing edge 
         ( 55 ) second peripheral edge portion 
         ( 56 ) first peripheral edge portion 
         ( 57 ) corner 
         ( 58 ) terminal edge 
         ( 61 ) solder 
         ( 100 ) antenna 
         ( 501 ) liner 
         ( 502 ) adhesive 
         ( 503 ) bottom solder mask 
         ( 504 ) flexible polymer 
         ( 505 ) first conductor 
         ( 506 ) top solder mask 
         ( 507 ) second conductor