Abstract:
The present invention is a device which includes an antenna and circuitry. The antenna may receive a circularly-polarized signal as first and second linearly-polarized signals. The circuitry is connected to the antenna and is configured for combining the first and second linearly-polarized signals to produce at least two reception patterns. The reception patterns are created by summing the first and second linearly-polarized signals via phase shifting. The reception patterns are optimized for at least two substantially different directional orientations. Further, the antenna may simultaneously allow/provide spec-compliant Global Positioning System operation and spec compliant Height of Burst operation.

Description:
FIELD OF THE INVENTION 
     The present invention relates to the field of Radio Frequency (RF) devices/advanced sensors and particularly to a low profile, conformal Global Positioning System (GPS) antenna array for artillery. 
     BACKGROUND OF THE INVENTION 
     A number of current RF device arrays may not provide a desired level of performance. 
     Thus, it would be desirable to provide an array/assembly which obviates the problems associated with current RF device arrays. 
     SUMMARY OF THE INVENTION 
     Accordingly, an embodiment of the present invention is directed to an assembly, including: a housing; a substrate, the substrate being connected to the housing to form a cavity; a plurality of chip antennas, the plurality of chip antennas being connected to the substrate and being at least substantially disposed within the cavity; circuitry, the circuitry being connected to the substrate, the circuitry further being connected to the plurality of antennas; and potting material, the potting material being disposed within the cavity and at least substantially filling the cavity, wherein the assembly is configured for implementation on-board a satellite navigation system-guided munition. 
     A further embodiment of the present invention is directed to an antenna assembly, including: a radome; a Radio Frequency flexible substrate, the substrate being connected to the housing to form a cavity; a plurality of chip antennas, the plurality of chip antennas being connected to the substrate and being at least substantially disposed within the cavity; circuitry, the circuitry being connected to the substrate, the circuitry further being connected to the plurality of antennas; and at least one Radio Frequency connector, the at least one Radio Frequency connector being connected to the substrate, the at least one Radio Frequency connector being connected, via the circuitry, to at least one chip antenna included in the plurality of chip antennas, wherein the antenna assembly is configured for implementation on-board a satellite navigation system-guided munition. 
     An additional embodiment of the present invention is directed to a side-mounted GPS patch antenna assembly for implementation on-board a GPS-guided munition, the assembly including: a radome, wherein the radome is formed of an injection-molded potting material; a Radio Frequency flexible substrate, the substrate being connected to the radome to form a cavity; a plurality of GPS-resonant chip antennas, the plurality of chip antennas being connected to the substrate and being at least substantially disposed within the cavity; circuitry, the circuitry being connected to the substrate, the circuitry further being connected to the plurality of antennas; and at least one Radio Frequency connector, the at least one Radio Frequency connector being connected to the substrate, the at least one Radio Frequency connector being connected, via the circuitry, to at least one chip antenna included in the plurality of chip antennas, wherein the cavity is at least substantially filled by the injection-molded potting material. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not necessarily restrictive of the invention as claimed. The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and together with the general description, serve to explain the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The numerous advantages of the present invention may be better understood by those skilled in the art by reference to the accompanying figures in which: 
         FIG. 1A  is an isometric exploded view of an antenna assembly in accordance with an exemplary embodiment of the present invention; 
         FIG. 1B  is a cross-sectional view of the antenna assembly of  FIG. 1A  in accordance with an exemplary embodiment of the present invention; 
         FIG. 2  is an isometric view of a chip antenna implemented in the antenna assembly shown in  FIG. 1A  and  FIG. 1B  in accordance with an exemplary embodiment of the present invention; 
         FIG. 3A  is a top plan view of an antenna assembly (without the housing/radome being shown) in accordance with a further exemplary embodiment of the present invention; 
         FIG. 3B  is a top plan view of an antenna assembly (without the housing/radome being shown) in accordance with a first alternative exemplary embodiment of the present invention; 
         FIG. 3C  is a top plan view of an antenna assembly (without the housing/radome being shown) in accordance with a second alternative exemplary embodiment of the present invention; 
         FIG. 3D  is a top plan view of an antenna assembly (without the housing/radome being shown) in accordance with a third alternative exemplary embodiment of the present invention; 
         FIG. 3E  is a top plan view of an antenna assembly (without the housing/radome being shown) in accordance with a fourth alternative exemplary embodiment of the present invention; 
         FIG. 4A  is a cutaway view of an artillery shell having previously available antenna assemblies implemented on-board said artillery shell in accordance with a prior art embodiment; and 
         FIG. 4B  is a cutaway view of an artillery shell having antenna assemblies implemented on-board said artillery shell, said antenna assemblies being in accordance with an exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. 
     Side-mounted, gun-hard Global Positioning System (GPS) patch antennas may be implemented with/on-board GPS-guided artillery/munitions/artillery applications/artillery platforms. For example, when space is unavailable on/within the nose of an artillery shell for a Dielectric Resonator Antenna (DRA), such side-mounted patch antennas may provide a desirable/viable alternative to embedding an edge slot antenna within the artillery shell. Alternatively, even when a nose-mounted DRA is implemented with/within/on-board an artillery shell, it may be desirable to implement a side-mounted patch antenna array in addition to/in tandem with the nose-mounted DRA for providing Anti-Jamming (AJ) functionality for the artillery shell. 
     However, currently available side-mounted, gun-hard GPS patch antennas are bulky. For example, currently available side-mounted, gun-hard GPS patch antennas/patches may include/may be configured inside of bulky housings (ex.—aluminum housings) in order to make the patches gun-hard. A further problem with currently available side-mounted, gun-hard GPS patch antennas  500  (see  FIG. 4A ) is that, when implemented on-board an artillery shell  400 , they may extend at least 0.5 inches into the body of the artillery shell  400  (ex.—into the interior of the artillery shell volume), as shown in  FIG. 4A . This extension/protrusion into the body/interior of the artillery shell may place costly constraints on currently available gun-hard receivers which are/may be implemented with GPS-guided artillery/munitions. 
     The exemplary embodiments of the present invention disclosed herein provide a low profile, conformal, gun-hard GPS antenna array/assembly which may be less expensive, lower profile (ex.—80% thinner and up to 50% shorter) and lighter weight than currently available solutions. Also, the exemplary embodiments of the present invention disclosed herein may provide low profile, conformal, gun-hard GPS antenna arrays/assemblies which are more versatile than currently available solutions (ex.—the arrays of the present invention may fit on several platforms upon which currently available solutions cannot). Further, the exemplary antenna array/assembly embodiments of the present invention described herein may promote increased compatibility with GPS receivers which may be implemented with GPS-guided artillery/munitions. Still further, the exemplary antenna array/assembly embodiments of the present invention described herein may provide supplemental AJ functionality on space-constrained platforms. 
     Referring generally to  FIGS. 1A ,  1 B and  3 A, an assembly in accordance with exemplary embodiments of the present invention is shown. The assembly  100  may be an antenna assembly/antenna array  100  (ex.—a band antenna assembly  100 ) which may be configured for implementation within/on-board/with a satellite navigation system-guided munition. For instance, the antenna assembly  100  may be configured for implementation on-board a Global Positioning System (GPS)-guided munition (ex.—a GPS-guided artillery shell  400 , as shown in  FIG. 4B ). In the embodiment illustrated in  FIG. 4B , the antenna assemblies  100  are implemented on-board the GPS-guided munition  400  as a side-mounted GPS patch antenna assembly  100 . The antenna assembly  100  may be configured for receiving satellite navigation system (ex.—GPS) signals for promoting/providing navigation functionality for the munition  400 . 
     In exemplary embodiments of the present invention, the antenna assembly  100  may include a housing  102 . For example, the housing  102  may be a radome  102 , such as a thin-walled radome  102  for an artillery shell  400 . The antenna assembly  100  may further include a substrate  104 . The substrate  104  may be connected to the housing/radome  102  to form a cavity/enclosure  106 . In current embodiments of the present invention, the substrate  104  may be a flexible substrate/Radio Frequency (RF) flexible substrate  104 . For instance, the substrate  104  may be formed of flexible circuit board material  104 . 
     In further embodiments of the present invention, the antenna assembly  100  may include a plurality of chip antennas  108 . In exemplary embodiments, the chip antennas  108  may be Commercial-Off-The-Shelf (COTS) chip antennas  108  (such as the chip antenna  108  shown in  FIG. 2 ). For instance, the chip antennas  108  may be COTS radiators (ex.—chip antennas designed for cell phones) which may be very inexpensive. The chip antennas  108  may be connected to the substrate  104  and may be at least substantially disposed within the cavity  106  formed by the housing  102  and the substrate  104  (as shown in  FIG. 1B ). For example, the cavity  106  formed by the housing  102  and the substrate  104  may provide a protective enclosure for the chip antennas  108 . 
     In exemplary embodiments of the present invention, the antenna assembly  100  may include circuitry  110 . The circuitry  110  may be connected to the substrate  104  and may also be connected to the antennas  108 . In further embodiments, the circuitry  110  may include one or more combiners  112  (ex.—a combiner network). For instance, each combiner  112  may be a coplanar waveguide (CPW) combiner  112 . In still further embodiments, the circuitry  110  may include an active circuitry portion  114  (as shown in  FIG. 3C ). 
     In further embodiments, the antenna assembly  100  may include one or more RF connectors  116 . Each RF connector  116  may be connected to the substrate  104  and may also be connected, via the circuitry  110 , to one or more of the chip antennas  108 . 
     In exemplary embodiments of the present invention, the antenna assembly  100  may include potting material  118 . The potting material  118  may be disposed within the cavity  106  formed by the housing/radome  102  and the substrate/RF flexible substrate  104 . For instance, the potting material  118  may at least substantially fill the cavity  106  (ex.—may fill the remaining unoccupied portion of the cavity/may fill the portion of the cavity not occupied by the antennas  108 ), thereby making the assembly  100  a gun-hard assembly  100 . 
     In further embodiments, the chip antennas  108  of the assembly  100  are sized to allow the assembly  100  to provide a lower profile, lighter weight alternative to previously available patch antenna solutions and may occupy a much smaller footprint along the length of the artillery shell  400  (see  FIG. 4B ) then previously available patch antenna solutions (shown in  FIG. 4A ). For example, one or more of the chip antenna(s)  108  may occupy a footprint which measures 10 millimeters by 3.2 millimeters (10.0 mm×3.2 mm) on the substrate/flex circuit/flex circuit board  104  and may have a thickness which measures 2.0 millimeters (2.0 mm). The cavity  106  may be sized to accommodate the chip antennas  108 . For instance, to accommodate/to allow sufficient clearance space for a chip antenna  108  having the above-referenced exemplary thickness dimension (ex.—2.0 mm), the cavity  106  may have a depth measurement/vertical axis depth measurement of 2.8 millimeters (2.8 mm) (as shown in  FIG. 1B ). In additional embodiments, the thickness/vertical axis depth measurement of the overall antenna assembly  100  may, for instance, be a measurement value ranging from 0.110 inches to 0.120 inches. In further embodiments, an exemplary footprint occupied by the substrate/flex circuit  104  may measure 180 millimeters by 15 millimeters (180 mm×15.0 mm). By being sized as described above, the antennas  108 /antenna assembly  100  of the exemplary embodiments of the present invention may be much thinner (ex.—80% thinner) and much shorter (ex.—50% shorter) than currently available antennas/antenna assemblies, thereby allowing the antenna assembly  100  of the exemplary embodiments of the present invention to fit on several platforms where existing gun-hard side mounted patch antennas/patches will not. 
     In the exemplary embodiment of the antenna assembly  100  shown in  FIGS. 1A ,  1 B and  3 A, four chip antennas  108  may be implemented, each of the four chip antennas  108  being L 1  GPS-resonant chip antennas  108  (shown as L 1  in  FIG. 3A ). Further, the embodiment of the antenna assembly  100  shown in  FIGS. 1A ,  1 B and  3 A implements a single combiner  112  connected to the four chip antennas  108 , and further implements a single RF connector  116  connected to the combiner  112  and the four chip antennas  108 . However, the antenna assembly  100  may be configured in/reconfigured into/adapted into a variety of alternative embodiments, as shown in  FIGS. 3B ,  3 C,  3 D and  3 E, thereby promoting ease of applying a consistent/flexible antenna design across multiple artillery platforms. For instance, an antenna assembly  200  in accordance with a first alternative exemplary embodiment of the present invention (as shown in  FIG. 3B ) may implement four chip antennas  108 . However, two of the four chip antennas  108  may be L 2  GPS-resonant chip antennas (shown as L 2  in  FIG. 3B ), while the remaining two of the four chip antennas  108  are L 1  GPS-resonant chip antennas (shown as L 1  in  FIG. 3B ). Further, the assembly  200  of  FIG. 3B  may implement two combiners  112 , a first combiner of said two combiners  112  connecting the L 1  GPS-resonant chip antennas  108 , a second of said two combiners connecting the L 2  GPS-resonant chip antennas  108 . The assembly  200  further implements two RF connectors  116 , a first RF connector of said two RF connectors  116  being connected to the L 1  GPS-resonant chip antennas via the first combiner  112 , a second RF connector of said two RF connectors  116  being connected to the L 2  GPS-resonant chip antennas via the second combiner  112 . 
     An antenna assembly  250  in accordance with a further alternative exemplary embodiment of the present invention (as shown in  FIG. 3C ) may implement two chip antennas  108  (ex.—two L 1  GPS-resonant chip antennas), one combiner  112  connected to the antennas  108 , and an RF connector  116  connected to the antennas  108  via the combiner  112 . Further, an active circuitry portion  114  may be connected between the combiner  112  and the RF connector  116 . An antenna assembly  300  in accordance with a further alternative exemplary embodiment of the present invention (as shown in  FIG. 3D ) may implement two chip antennas  108  (ex.—two L 1  GPS-resonant chip antennas), one combiner  112  connected to the antennas  108 , and an RF connector  116  connected to the antennas  108  via the combiner  112 . An antenna assembly  350  in accordance with a further alternative exemplary embodiment of the present invention (as shown in  FIG. 3E ) may implement four chip antennas  108  (ex.—four L 1  GPS-resonant chip antennas) and four RF connectors  116 , each RF connector being connected to the chip antennas  108  in a dedicated manner (ex.—a first chip antenna included in the four chip antennas being connected to a first RF connector included in the four RF connectors, a second chip antenna included in the four chip antennas being connected to a second RF connector included in the four RF connectors, etc.). 
     The above-referenced exemplary embodiments of the antenna assembly ( 100 ,  200 ,  250 ,  300 ,  350 ) illustrate the flexibility of the antenna assembly of the present invention and how it may be configured/adapted to provide any one of various multiple antenna offerings in a single footprint. This flexibility may allow for accommodation of many different programs via a single form factor with short turnaround times when a new requirement arises. Further, such flexibility, and the above-referenced low profile characteristics of the antenna assembly  100  of the exemplary embodiments of the present invention may promote improved (ex.—universal) compatibility with various GPS electronics (ex. GPS receivers) and Inertial guidance electronics. 
     In further exemplary embodiments, the antenna assembly  100 /chip antennas  108  may be configured for being switched. For example, if the antenna assembly  100  is implemented on-board a GPS-guided munition, the antenna assembly/array  100  may be switched from/may transition from a first operating mode (ex.—Mode 1) to a second operating mode (ex.—Mode 0) when the GPS-guided munition is in mid-flight. 
     In additional embodiments, the antenna assembly  100 /chip antennas  108  may provide similar gain characteristics as linearly-polarized edge slot antennas. Further, the antenna assembly  100  may work well as a secondary antenna assembly in an Anti-Jamming (AJ) system, said AJ system implementing a nose-mounted Dielectric Resonator Antenna (DRA) as the primary signal reference. For instance, the antenna assembly  100  may provide additional/supplemental anti-jamming capability on space-constrained platforms. 
     In further embodiments, the potting material  118  may be injection-molded potting material for filling/partially filling/at least substantially filling the cavity  106 . In still further embodiments, the radome  102  may be formed of the injection-molded potting material. 
     It is believed that the present invention and many of its attendant advantages will be understood by the foregoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely an explanatory embodiment thereof, it is the intention of the following claims to encompass and include such changes.