Abstract:
A Tapered Slot Antenna Cylindrical Array (NC#97194). The apparatus includes a base and a tapered slot antenna array. The base is capable of retaining a plurality of tapered slot antenna pairs. The tapered slot antenna array is operatively coupled to the base in a cylindrical configuration. The tapered slot antenna array comprises at least two tapered slot antenna pairs. Each tapered slot antenna pair of the at least two tapered slot antenna pairs is capable of operating independently of or in conjunction with other tapered slot antenna pairs of the at least two tapered slot antenna pairs to enable direction finding, acquisition, communication and electronic attack capabilities.

Description:
FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT 
   This invention (Navy Case No. 97194) is assigned to the United States Government and is available for licensing for commercial purposes. Licensing and technical inquiries may be directed to the Office of Research and Technical Applications, Space and Naval Warfare Systems Center, San Diego, Code 2112, San Diego, Calif., 92152; voice (619) 553-2778; email T2@spawar.navy.mil. Reference Navy Case Number 97194. 

   CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is related to U.S. Pat. No. 7,009,572, issued on Mar. 7, 2006, entitled “Tapered Slot Antenna”, by Rob Horner et al., Navy Case No. 96507, which is hereby incorporated by reference in its entirety herein for its teachings on antennas. This application is also related to U.S. Ser. No. 10/932,646 filed on Aug. 31, 2004, entitled “Concave Tapered Slot Antenna” by Rob Horner et al., Navy Case No. 96109, which is hereby incorporated by reference in its entirety herein for its teachings on antennas. 
   BACKGROUND OF THE INVENTION 
   The present invention is generally in the field of antennas. 
   Typical antenna arrays require at least one separate antenna or antenna set for each of the following capabilities: direction finding (DF), acquisition (ACQ), communication (COM) and information operations (IOP). Thus, typical antenna arrays that have multiple capabilities are large, bulky and expensive. In addition, typical antenna arrays lack ultra broad band frequency capabilities and lack high gain/directivity. 
   A need exists for a small, inexpensive antenna array having DF, ACQ, COM and IOP capabilities, as well as, ultra broad band frequency capabilities and high gain/directivity. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     All FIGURES are not drawn to scale. 
       FIG. 1A  is a top and side view of one embodiment of a TSACA. 
       FIG. 1B  is a top and side view of one embodiment of a TSACA. 
       FIG. 2  is a top and partial side view of one embodiment of a TSACA. 
       FIG. 3A  is a top view of one embodiment of a TSACA. 
       FIG. 3B  is a top view of several embodiments of a TSACA. 
       FIG. 4  is a block diagram of one embodiment of a TSACA system. 
       FIG. 5  is a side view of one embodiment of a TSACA system. 
       FIG. 6  is a top view of one embodiment of a TSACA system. 
       FIG. 7A  is a side and top view of some of the features of an exemplary TSA formed in accordance with one embodiment of a TSACA. 
       FIG. 7B  is a side view of some of the features of an exemplary TSA formed in accordance with one embodiment of a TSACA. 
       FIG. 8  is a flowchart of an exemplary method of manufacturing one embodiment of a TSACA. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The present invention is directed to Tapered Slot Antenna Cylindrical Arrays. 
   DEFINITIONS 
   The following acronyms and definition(s) are used herein: 
   Acronym(s): 
   ACQ—Acquisition 
   COM—Communication 
   DF—Direction Finding 
   I/O—Input/Output 
   IOP—Information Operations 
   RF—Radio Frequency 
   TSA—Tapered Slot Antenna 
   TSACA—Tapered Slot Antenna Cylindrical Array 
   Tx/Rx—Transmitter/Receiver 
   Definition(s): 
   Information Operations—Radio Frequency Jamming and/or Electronic Attack 
   The tapered slot antenna cylindrical array (TSACA) includes a base and a tapered slot antenna (TSA) array operatively coupled to the base. The TSACA includes at least two tapered slot antenna pairs. In one embodiment, at least one angle formed between adjacent tapered slot antenna pairs with respect to a transverse plane is different than the remaining angles formed between adjacent tapered slot antenna pairs with respect to a transverse plane. In one embodiment, each tapered slot antenna pair forms approximately equal angles with respect to adjacent tapered slot antenna pairs with respect to a transverse plane. In addition, each TSA pair is capable of operating independently of or in conjunction with other TSA pairs of the TSACA. Thus, the TSACA is capable of DF, ACQ, COM and IOP. In one embodiment, the TSACA includes two TSA pairs. In one embodiment, the TSACA includes three TSA pairs. In one embodiment, the TSACA includes four TSA pairs. In one embodiment, the TSACA includes five TSA pairs. In one embodiment, the TSACA includes six TSA pairs. In one embodiment, the TSACA includes eight TSA pairs. In one embodiment, the TSACA includes sixteen TSA pairs. In one embodiment, the TSACA includes thirty-two TSA pairs. In one embodiment, the TSACA includes a radome to enclose the TSA pairs. In one embodiment, the base comprises a single cylindrical element. In one embodiment, the base comprises two hemi-cylindrical elements. In one embodiment, the TSACA is operatively coupled to a mast of a ship via the base of the TSACA. In one embodiment, the TSACA is operatively coupled to a pole mounted on a building, antenna tower, bridge or other tall structure via the base of the TSACA. 
     FIG. 1A  is a top and side view of one embodiment of a tapered slot antenna cylindrical array. As shown in  FIG. 1A , TSACA  102  includes base element  104 , TSA pair  120  and TSA pair  150 . Base element  104  comprises a material capable of supporting TSA pairs  120 ,  150 . In one embodiment, base element  104  comprises a substantially nonconductive material such as, for example, plastic and G 10 , wherein TSA pairs  120 ,  150  directly connect to base element  104 . In one embodiment, base element  104  comprises a substantially conductive material such as, for example, aluminum and steel, wherein TSA pairs  120 ,  150  are operatively coupled to base element  104  using a substantially non-conductive brace (see brace  740  of  FIG. 7A ). Base element  104  has a cylindrical configuration. Base element  104  is adapted to be operatively coupled to a cylindrical structure such as a ship mast or a pole mounted to a tall structure. Base element  104  is adapted to retain TSA pairs  120 ,  150 . 
   TSA pairs  120 ,  150  form a TSA array having a cylindrical configuration. TSA pairs  120 ,  150  are operatively coupled to base element  104 . As shown in the top view of  FIG. 1A , TSACA  102  is configured so that angles θ 1  and θ 2  formed between adjacent TSA pairs (i.e., TSA pairs  120 ,  150 ) with respect to a transverse plane form approximately equal angles. Thus, approximately 180 degree angles (θ 1  and θ 2 ) are formed between adjacent TSA pairs of TSACA  102  with respect to a transverse plane. It should be appreciated, however, that TSACA  102  is can be configured so that angles formed between adjacent TSA pairs with respect to a transverse plane form unequal angles. For example, TSA pair  120  and TSA pair  150  shown at  FIG. 1  could be arranged so that θ 1 =140 degrees and θ 2  equals 220 degrees. Each TSA pair (i.e., TSA pair  120 , TSA pair  150 ) includes two TSA elements situated in a TSA configuration. As shown in  FIG. 1A , TSA pair  120  includes TSA element  122  and TSA element  124 ; and TSA pair  150  includes TSA element  152  and TSA element  154 . TSA elements  122 ,  124 ,  152 ,  154  comprise a substantially conductive material such as, for example, stainless steel and aluminum. TSA elements  122 ,  124 ,  152 ,  154  are capable of transmitting and receiving radio frequency (RF) energy. 
   TSA elements  122 ,  124 ,  152 ,  154  have feed ends (ends closer to base element  104 ) and launch ends (ends farther from base element  104 ). The feed ends can be operatively coupled to an input/output (I/O) feed such as a coaxial cable. The I/O feed can be used to transmit and receive RF signals to and from TSACA  102 . RF signals can be transmitted from the feed end toward the launch end, wherein the RF signals launch from an antenna pair at a point between the feed end and the launch end depending upon the signal frequency. RF signals having higher frequencies launch closer to the feed end and RF signals having lower frequencies launch closer to the launch end. TSA pairs  120 ,  150  are capable of operating independently of or in conjunction with each other. Thus, TSACA  102  is capable of DF, ACQ, COM and IOP. 
     FIG. 1B  is a top and side view of one embodiment of a tapered slot antenna cylindrical array. As shown in  FIG. 1B , TSACA  100  includes first base element  110 , second base element  140 , TSA pair  120 , TSA pair  130 , TSA pair  150  and TSA pair  160 . First base element  110  and second base element  140  comprise a substantially nonconductive material such as, for example, plastic and G 10 . First base element  110  and second base element  140  each have a hemi-cylindrical (i.e., half-pipe) configuration. First base element  110  is operatively coupled to second base element  140  to form a cylinder having a cylindrical cavity. First base element  110  and second base element  140  are adapted to be operatively coupled to a cylindrical structure such as a ship mast. First and second base elements  110 ,  140  are adapted to retain TSA pairs  120 ,  130 ,  150 ,  160 . 
   TSA pairs  120 ,  130 ,  150 ,  160  form a TSA array having a cylindrical configuration. TSA pairs  120 ,  130  are operatively coupled to first base element  110 . TSA pairs  150 ,  160  are operatively coupled to second base element  140 . As shown in the top view of  FIG. 11B , TSACA  100  is configured so that angles formed between adjacent TSA pairs (e.g., TSA pairs  120 ,  130 ,  150 ,  160 ) form approximately equal angles with respect to a transverse plane. Thus, approximately 90 degree angles are formed between adjacent TSA pairs of TSACA  100  with respect to a transverse plane. Each TSA pair (i.e., TSA pair  120 , TSA pair  130 , TSA pair  150  and TSA pair  160 ) includes two TSA elements situated in a TSA configuration. As shown in  FIG. 1B , TSA pair  120  includes TSA element  122  and TSA element  124 ; TSA pair  130  includes TSA element  132  and another TSA element (not shown in  FIG. 1B ); TSA pair  150  includes TSA element  152  and TSA element  154 ; and TSA pair  160  includes TSA element  162  and TSA element  164 . TSA elements  122 ,  124 ,  132 ,  152 ,  154 ,  162 ,  164  comprise a substantially conductive material such as, for example, stainless steel and aluminum. TSA elements  122 ,  124 ,  132 ,  152 ,  154 ,  162 ,  164  are capable of transmitting and receiving radio frequency (RF) energy. 
   TSA elements  122 ,  124 ,  132 ,  152 ,  154 ,  162 ,  164  have feed ends (ends closer to first and second base elements  110 ,  140 ) and launch ends (ends farther from first and second base elements  110 ,  140 ). The feed ends can be operatively coupled to an input/output (I/O) feed such as a coaxial cable. The I/O feed can be used to transmit and receive RF signals to and from TSACA  100 . RF signals can be transmitted from the feed end toward the launch end, wherein the RF signals launch from an antenna pair at a point between the feed end and the launch end depending upon the signal frequency. RF signals having higher frequencies launch closer to the feed end and RF signals having lower frequencies launch closer to the launch end. TSA pairs  120 ,  130 ,  150 ,  160  are capable of operating independently of or in conjunction with each other. Thus, TSACA  100  is capable of DF, ACQ, COM and IOP. 
   In one embodiment, TSA elements  122 ,  124  have curvatures that can each be represented by the following Equation 1:
 
 Y ( x )= a ( e   bx −1);  (Equation 1)
         where, a and b are parameters selected to produce a desired curvature. In one embodiment, parameters “a” and “b” are approximately equal to 0.2801 and 0.1028, respectively, and x is the length of the element and Y is the width of the element.       

     FIG. 2  is a top and partial side view of one embodiment of a tapered slot antenna cylindrical array. TSACA  200  of  FIG. 2  is substantially similar to TSACA  100  of  FIG. 1B , and thus, similar components are not described again in detail hereinbelow. As shown in  FIG. 2 , TSACA  200  includes first base element  110 , second base element  140  and eight TSA pairs corresponding to TSA elements  122 ,  132 ,  142 ,  152 ,  162 ,  172 ,  182 ,  192  (e.g., TSA pair  120  corresponds to TSA element  122 ). 
   TSA pairs corresponding to TSA elements  122 ,  132 ,  142 ,  152 ,  162 ,  172 ,  182 ,  192  form a TSA array having a cylindrical configuration. TSA pairs corresponding to TSA elements  122 ,  132 ,  142 ,  152  are operatively coupled to first base element  110 . TSA pairs corresponding to TSA elements  162 ,  172 ,  182 ,  192  are operatively coupled to second base element  140 . As shown in the top view of  FIG. 2 , TSACA  200  is configured so that angles formed between adjacent TSA pairs form approximately equal angles with respect to a transverse plane. Thus, approximately 45 degree angles are formed between adjacent TSA pairs of TSACA  200  with respect to a transverse plane. Each TSA pair includes two TSA elements situated in a TSA configuration. As shown in  FIG. 2  with regard to the partial side view along line  190 , TSA pair  120  includes TSA element  122  and TSA element  124 . TSA pairs corresponding to TSA elements  122 ,  132 ,  142 ,  152 ,  162 ,  172 ,  182 ,  192  comprise a substantially conductive material such as, for example, stainless steel and aluminum and are capable of transmitting and receiving RF energy. TSA pairs corresponding to TSA elements  122 ,  132 ,  142 ,  152 ,  162 ,  172 ,  182 ,  192  are capable of operating independently of or in conjunction with each other. Thus, TSACA  200  is capable of DF, ACQ, COM and IOP. 
     FIG. 3A  is a top view of one embodiment of a tapered slot antenna cylindrical array. TSACA  300  of  FIG. 3A  is substantially similar to TSACA  100 ,  102  of  FIGS. 1A and 1B , and thus, similar components are not described again in detail hereinbelow. As shown in  FIG. 3A , TSACA  300  includes first base element  10 , second base element  140  and six TSA pairs corresponding to TSA elements  122 ,  132 ,  142 ,  152 ,  162 ,  172 . 
   TSA pairs corresponding to TSA elements  122 ,  132 ,  142 ,  152 ,  162 ,  172  form a TSA array having a cylindrical configuration. TSA pairs corresponding to TSA elements  122 ,  132 ,  142  are operatively coupled to first base element  110 . TSA pairs corresponding to TSA elements  152 ,  162 ,  172  are operatively coupled to second base element  140 . As shown in  FIG. 3A , TSACA  300  is configured so that angles formed between adjacent TSA pairs form approximately equal angles with respect to a transverse plane. Thus, approximately 60 degree angles are formed between adjacent TSA pairs of TSACA  300  with respect to a transverse plane. Each TSA pair includes two TSA elements situated in a TSA configuration. TSA pairs corresponding to TSA elements  122 ,  132 ,  142 ,  152 ,  162 ,  172  comprise a substantially conductive material such as, for example, stainless steel and aluminum and are capable of transmitting and receiving RF energy. TSA pairs corresponding to TSA elements  122 ,  132 ,  142 ,  152 ,  162 ,  172  are capable of operating independently of or in conjunction with each other. Thus, TSACA  300  is capable of DF, ACQ, COM and IOP. 
     FIG. 3B  is a top view of several embodiments of a tapered slot antenna cylindrical array. All figures of  FIG. 3B  are not drawn to scale. TSACA  302 ,  304 ,  306 ,  308  of  FIG. 3B  are substantially similar to TSACA  100 ,  102  of  FIGS. 1A and 1B , and thus, similar components are not described again in detail hereinbelow. As shown in  FIG. 3B , TSACA  302  includes a base element having a cylindrical configuration and three TSA pairs operatively coupled to the base element. TSACA  302  is configured so that angles formed between adjacent TSA pairs with respect to a transverse plane form at least one unequal angle relative to the other angles. 
   As shown in  FIG. 3B , TSACA  304  includes a base element having a cylindrical configuration and five TSA pairs operatively coupled to the base element. TSACA  304  is configured so that angles formed between adjacent TSA pairs with respect to a transverse plane form at least one unequal angle relative to the other angles. 
   As shown in  FIG. 3B , TSACA  306  includes a base element having a cylindrical configuration and sixteen TSA pairs operatively coupled to the base element. TSACA  306  is configured so that angles formed between adjacent TSA pairs with respect to a transverse plane form at least one unequal angle relative to the other angles. 
   As shown in  FIG. 3B , TSACA  308  includes a base element having a cylindrical configuration and thirty-two TSA pairs operatively coupled to the base element. TSACA  308  is configured so that angles formed between adjacent TSA pairs with respect to a transverse plane form at least one unequal angle relative to the other angles. 
     FIG. 4  is a block diagram of one embodiment of a TSACA system. As shown in  FIG. 4 , TSACA system  400  includes TSACA  410 , RF link  420 , Transmitter/Receiver (Tx/Rx)  430 , communication link  440  and microprocessor  450 . TSACA  410  is capable of DF, ACQ, COM and IOP. Exemplary embodiments of TSACA  410  include TSACA  100 ,  200 ,  300  of  FIGS. 1 ,  2 ,  3 , respectively. TSACA  410  is operatively coupled to Tx/Rx  430  via RF link  420 . RF link  420  is capable of providing RF signals to and from TSACA  410  and Tx/Rx  430 . In one embodiment, RF link  420  comprises a plurality of coaxial cables, wherein each TSA pair of TSACA  410  is operatively coupled to a separate coaxial cable. RF link  420  is also capable of providing electronics control signals for one or more electronics devices operatively coupled to TSACA  410 . For example, RF link  420  is capable of providing electronics control signals for commutators (i.e., switch matrices), RF amplifiers, limiters and filters that are operatively coupled to TSACA  410 . 
   Tx/Rx  430  of  FIG. 4  is capable of generating, transmitting and receiving RF signals. Tx/Rx  430  is capable of receiving multiple RF signals from TSACA  410 . Tx/Rx  430  is capable of contemporaneously receiving RF signals from two or more TSA pairs of TSACA  410 . Tx/Rx  430  is capable of generating and transmitting multiple RF signals to TSACA  410 . Tx/Rx  430  is capable of contemporaneously transmitting RF signals to two or more TSA pairs of TSACA  410  in response to microprocessor  450 . Tx/Rx  430  is operatively coupled to microprocessor  450  via communication link  440 . Microprocessor  450  is capable of receiving RF signals from Tx/Rx  430 . Microprocessor  450  is capable of controlling the output of Tx/Rx  430  so that multiple RF signals can be transmitted to two or more TSA pairs of TSACA  410 . 
     FIG. 5  is a side view of one embodiment of a TSACA system. The TSACA system of  FIG. 5  includes a TSACA operatively coupled to a structure and encased in a radome. As shown in  FIG. 5 , TSACA system  500  includes a TSACA operatively coupled to structure  504  and encased by radome  502 . The TSACA includes four TSA pairs. One TSA pair comprises TSA elements  122 ,  124 . Another TSA pair comprises TSA elements  152 ,  154 . In one embodiment, structure  504  comprises a mast of a ship. In one embodiment, structure  504  comprises a pole fixed to a stationary object such as a building. Radome  502  comprises dielectric material capable of substantially encapsulating the TSACA of  FIG. 5 . In one embodiment, radome  502  is capable of substantially sealing the TSACA from an external environment. In one embodiment, radome  502  is electrically transparent to all RF energy. In one embodiment, radome  502  is electrically transparent to a band of RF energy. In one embodiment, radome  502  comprises frequency selective surface material. In one embodiment, radome  502  comprises durable material. In one embodiment, radome  502  comprises fiberglass cloth with polyester resin. 
     FIG. 6  is a top view of one embodiment of a TSACA system of  FIG. 5 . As shown in  FIG. 6 , TSA pairs corresponding to TSA elements  122 ,  132 ,  152 ,  162  are enclosed by radome  502 . The TSACA of  FIG. 6  is operatively coupled to structure  504 . In one embodiment, the TSACA of  FIG. 6  is operatively coupled by attaching first base element  110  and second base element  140  around structure  504  in a cylindrical fashion. 
     FIGS. 7A-7B  show some of the features of an exemplary TSA formed in accordance with one embodiment of a TSACA.  FIG. 7A  is a side, front and bottom view of some of the features of an exemplary TSA  700  formed in accordance with one embodiment of a TSACA.  FIG. 7A  is a side, front and bottom view of one embodiment of brace  740 . Brace  740  comprises a substantially nonconductive material such as, for example, plastic and G 10 . As shown in  FIG. 7A , brace  740  includes slots  747 ,  748 , apertures  742 ,  744  and receiver aperture  746 . Slots  747 ,  748  are adapted to snugly receive TSA elements in a tapered slot antenna configuration. Apertures  742 ,  744  are adapted to substantially align with apertures formed within TSA elements so that a fastener such as a threaded screw can operatively couple TSA elements to brace  740 . Apertures  742 ,  744  are adapted to decrease the width of slots  747 ,  748  when used in conjunction with fasteners such as nuts and bolts, and thus, TSA elements can be securely coupled to brace  740  using slots  747 ,  748 . In one embodiment, apertures  742 ,  744  are threaded apertures. Receiver aperture  746  is adapted to receive an I/O feed such as an outer jacket of a coaxial cable. 
     FIG. 7B  is a side view of some of the features of an exemplary TSA formed in accordance with one embodiment of a TSACA. As shown in  FIG. 7B , first TSA element  710  is operatively coupled to brace  740  via fasteners (represented on  FIG. 7B  by the symbol “X”) used in conjunction with apertures  742 . Similarly, second TSA element  720  is operatively coupled to brace  740  via fasteners (represented on  FIG. 7B  by the symbol “X”) used in conjunction with apertures  744 . The TSA pair (i.e., first TSA element  710  and second TSA element  720 ) of TSA  700  has gap height  794 . Brace  740  is capable of being operatively coupled to base elements  110 ,  140  of  FIGS. 1 ,  2 ,  3  and  6 . 
     FIG. 8  includes flowcharts illustrating exemplary processes to implement an exemplary TSACA. While flowcharts  800 ,  802  are sufficient to describe one embodiment of an exemplary TSACA, other embodiments of the TSACA may utilize procedures different from those shown in flowcharts  800 ,  802 .