Patent Publication Number: US-11031702-B2

Title: Phased array antenna structure

Description:
FIELD OF THE DISCLOSURE 
     The present disclosure relates to an antenna structure, and more particularly to a phased array antenna structure. 
     BACKGROUND OF THE DISCLOSURE 
     A conventional antenna structure is provided with an expensive phase shifter to satisfy different pattern requirements. In other words, the conventional antenna structure for generating different patterns has to cooperate with a phase shifter, which is an established impression in the antenna field, so that the improvement of the conventional antenna structure has been neglected. 
     SUMMARY OF THE DISCLOSURE 
     In response to the above-referenced technical inadequacies, the present disclosure provides a phased array antenna structure to effectively improve the issues associated with conventional antenna structures. 
     In one aspect, the present disclosure provides a phased array antenna structure, which includes a carrier, a radiative layer, a circuit layer, and N number of phase switching units. The radiative layer includes N number of radiating portions disposed on the carrier, and N is a positive integer greater than one. The circuit layer is disposed on the carrier and includes N number of phased antenna units and a transmission circuit. The N number of phased antenna units respectively correspond in position to the N numbers of the radiating portions. Each of the phase switching units includes a plurality of phased antennas spaced apart from each other and having different lengths. The transmission circuit includes a feeding end and N number of externally connecting ends. The N number of the externally connecting ends are respectively arranged adjacent to the N number of the phased antenna units. The N number of the phase switching units respectively correspond in position to the N number of the phased antenna units. The N number of phase switching units are respectively connected to the N number of the externally connecting ends of the transmission circuit, and are respectively connected to the N number of radiating portions. In each of the phased antenna units and the corresponding phase switching unit, the phase switching unit is configured to selectively connect with only one of the phased antennas, so that the phased array antenna structure is able to generate at least 2N number of antenna patterns. 
     In one aspect, the present disclosure provides a phased array antenna structure, which includes a carrier, a radiative layer, a circuit layer, and a phase switch. The radiative layer includes two radiating portions disposed on the carrier. The circuit layer is disposed on the carrier and includes a phased antenna and a transmission circuit. The phased antenna includes two end portions respectively connected to the two radiating portions. The transmission circuit includes a feeding end and an externally connecting end that is arranged adjacent to the phased antenna. The phase switch is connected to the externally connecting end of the transmission circuit, and the phase switch is configured to selectively connect with only one of the two end portions of the phased antenna. 
     Therefore, the phased array antenna structure in the present disclosure can effectively use the phase switching units (or the phase switch) by the structural design and the cooperation of the radiative layer and the circuit layer, so that phased array antenna structure of the present disclosure can be formed without the phase shifter that is at least ten times more expensive than the phase switches. 
     These and other aspects of the present disclosure will become apparent from the following description of the embodiment taken in conjunction with the following drawings and their captions, although variations and modifications therein may be affected without departing from the spirit and scope of the novel concepts of the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure will become more fully understood from the following detailed description and accompanying drawings. 
         FIG. 1  is a perspective view of a phased array antenna structure according to a first embodiment of the present disclosure. 
         FIG. 2  is a top view of  FIG. 1 . 
         FIG. 3  is a top view of  FIG. 1  with a phase switching unit omitted. 
         FIG. 4  is a schematic view showing a first operation mode of the phased array antenna structure according to the first embodiment of the present disclosure. 
         FIG. 5  is an antenna pattern view of  FIG. 4 . 
         FIG. 6  is a schematic view showing a second operation mode of the phased array antenna structure according to the first embodiment of the present disclosure. 
         FIG. 7  is an antenna pattern view of  FIG. 6 . 
         FIG. 8  is a schematic view showing a third operation mode of the phased array antenna structure according to the first embodiment of the present disclosure. 
         FIG. 9  is an antenna pattern view of  FIG. 8 . 
         FIG. 10  is a schematic view showing a fourth operation mode of the phased array antenna structure according to the first embodiment of the present disclosure. 
         FIG. 11  is an antenna pattern view of  FIG. 10 . 
         FIG. 12  is a planar view of a phased array antenna structure according to a second embodiment of the present disclosure. 
         FIG. 13  is a planar view of  FIG. 12  with a phase switching unit omitted. 
         FIG. 14  is an antenna pattern view showing a first operation mode of the phased array antenna structure according to the second embodiment of the present disclosure. 
         FIG. 15  is an antenna pattern view showing a second operation mode of the phased array antenna structure according to the second embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
     The present disclosure is more particularly described in the following examples that are intended as illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art. Like numbers in the drawings indicate like components throughout the views. As used in the description herein and throughout the claims that follow, unless the context clearly dictates otherwise, the meaning of “a”, “an”, and “the” includes plural reference, and the meaning of “in” includes “in” and “on”. Titles or subtitles can be used herein for the convenience of a reader, which shall have no influence on the scope of the present disclosure. 
     The terms used herein generally have their ordinary meanings in the art. In the case of conflict, the present document, including any definitions given herein, will prevail. The same thing can be expressed in more than one way. Alternative language and synonyms can be used for any term(s) discussed herein, and no special significance is to be placed upon whether a term is elaborated or discussed herein. A recital of one or more synonyms does not exclude the use of other synonyms. The use of examples anywhere in this specification including examples of any terms is illustrative only, and in no way limits the scope and meaning of the present disclosure or of any exemplified term. Likewise, the present disclosure is not limited to various embodiments given herein. Numbering terms such as “first”, “second” or “third” can be used to describe various components, signals or the like, which are for distinguishing one component/signal from another one only, and are not intended to, nor should be construed to impose any substantive limitations on the components, signals or the like. 
     First Embodiment 
     Referring to  FIG. 1  to  FIG. 11 , a first embodiment of the present disclosure provides a phased array antenna structure  100 . Each of the drawings are provided with X axis, Y axis, and Z axis for clearly describing the present embodiment. As shown in  FIG. 1  to  FIG. 3 , the phased array antenna structure  100  in the present embodiment is operated in a frequency band that has a center frequency corresponding to a wavelength (i.e., the center frequency is a reciprocal of the wavelength). The phased array antenna structure  100  includes a carrier  1 , a radiative layer  2  and a circuit layer  3  both disposed on the carrier  1 , and N number of phase switching units  40  mounted on the carrier  1  and corresponding in position to the circuit layer  3 . 
     Specifically, “N” is a positive integer greater than one, and “N” in the present embodiment is four, but the present disclosure is not limited thereto. For example, in other embodiments of the present disclosure, “N” can be two, three, or at least five. In addition, the phased array antenna structure  100  can further include other components (e.g., a grounding layer) disposed on the carrier  1 , but the related description in the present embodiment will be omitted for the sake of brevity. 
     As shown in  FIG. 1  to  FIG. 3 , the carrier  1  in the present embodiment is a flat board, and includes a first surface  11  and a second surface  12  opposite to the first surface  11 . The radiative layer  2  is disposed on the first surface  11  of the carrier  1 , and the circuit layer  3  and the N number of the phase switching units  40  are disposed on the second surface  12  of the carrier  1 , but the present disclosure is not limited thereto. For example, in other embodiments of the present disclosure, the radiative layer  2  and at least one of the circuit layer  3  and the N number of the phase switching units  40  can be disposed on the same surface of the carrier  1 . 
     The radiative layer  2  includes N number of radiating portions  21 , and the N number of the radiating portions  21  in the present embodiment have the same shape (e.g., square) and are formed on the first surface  11  of the carrier  1  in a matrix arrangement. The circuit layer  3  includes N number of phased antenna units  31  respectively corresponding in position to the number of the radiating portions  21  and a transmission circuit  32  corresponding in position to the N number of the phased antenna units  31 . 
     Specifically, each of the phased antenna units  31  includes a plurality of phased antennas  311  spaced apart from each other and having different lengths. In the present embodiment, the carrier  1  includes a plurality of conductive posts  13 , and each of the phased antennas  311  is electrically coupled to the corresponding radiating portion  21  through one of the conductive posts  13 . 
     Moreover, the different lengths of the phased antennas  311  of each of the phased antenna units  31  are multiples of ¼ of the wavelength. In other words, the lengths of the three phased antennas  311  of each of the phased antenna units  31  shown in  FIG. 3  are respectively ¼, 2/4, and ¾ of the wavelength, but the present disclosure is not limited thereto. In each of the phased antenna units  31 , at least one of the phased antennas  311  has a U-shaped portion that can also be regarded as a C-shape portion. 
     In addition, in each of the phased antenna units  31  and the corresponding radiating portion  21 , a projected region defined by orthogonally projecting the radiating portion  21  onto the second surface  12  of the carrier  1  covers at least part of the phased antenna unit  31  (or at least part of each of the phased antennas  311 ). 
     As shown in  FIG. 1  to  FIG. 3 , the transmission circuit  32  includes a feeding circuit  321  and a branch circuit  322  connected to the feeding circuit  321 . The feeding circuit  321  in the present embodiment is in a substantial straight shape and has a feeding end  3211  and a connecting end  3212 . The feeding end  3211  is disposed on (or flush with) an edge of the carrier  1 . The feeding circuit  321  extends from the feeding end  3211  to the connecting end  3212  (or the branch circuit  322 ) by passing through a region between two of the phased antenna units  31  adjacent to each other. The feeding end  3211  is configured to connect and fix to an electrical connector (not shown), thereby establishing a signal transmission path from the phased array antenna structure  100  to an external device. 
     The branch circuit  322  in the present embodiment is in a substantial H-shape, and includes N number of externally connecting ends  3221  respectively arranged adjacent to the N number of the phased antenna units  31 . In other words, distal ends of the branch circuit  322  are the externally connecting ends  3221 , and each of the externally connecting ends  3221  is spaced apart from the corresponding phased antenna unit  31 . 
     Moreover, the connecting end  3212  of the feeding circuit  321  is connected to the branch circuit  322 . The N number of the externally connecting ends  3221  define a plurality of cross lines L each connecting two of the N number of the externally connecting ends  3221 , and the connecting end  3212  is substantially located at a point intersection of the cross lines L. In the present embodiment, a plurality of paths respectively defined from the N number of the externally connecting ends  3221  to the connecting end  3212  have the same distance. In other words, the connecting end  3212  of the feeding circuit  321  is connected to a central point of the branch circuit  322  for synchronous signal transmission, but the present disclosure is not limited thereto. 
     In other words, two of the phased antenna units  31  adjacent to the feeding end  3211  (e.g., the right two phased antenna units  31  shown in  FIG. 3 ) and the other two of the phased antenna units  31  (e.g., the left two phased antenna units  31  shown in  FIG. 3 ) are in a 2-fold rotational symmetry with respect to the connecting end  3212 . 
     The N number of the phase switching units  40  respectively correspond in position to the N number of the phased antenna units  31 , and each of the phase switching units  40  in the present embodiment is arranged adjacent to the corresponding phased antenna unit  31 . The N number of the phase switching units  40  are respectively connected to the N number of the externally connecting ends  3221  of the transmission circuit  32 , and are respectively connected to the N number of radiating portions  21 . In the present embodiment, each of the phase switching units  40  includes two phase switches ( 4 ,  4   a ). In each of the phase switching units  40 , one of the two phase switches  4  is connected to the corresponding externally connecting end  3221 , and the other phase switch  4   a  is connected to the corresponding radiating portion  21  through one of the conductive posts  13  embedded in the carrier  1 , but the present disclosure is not limited thereto. For example, in other embodiments of the present disclosure, the phase switch ( 4 ,  4   a ) can be indirectly connected to the externally connecting end  3221  or the radiating portion  21  through a cable, or the phase switching unit  40  can be a single phase switch. 
     Moreover, in each of the phased antenna units  31  and the corresponding phase switching unit  40 , the phase switching unit  40  is configured to selectively connect only one of the phased antennas  311 , so that the phased array antenna structure  100  is able to generate at least 2N number of antenna patterns P. In other words, the two phase switches ( 4 ,  4   a ) of the phase switching unit  40  are configured to selectively connect the same phased antenna  311 . In addition, according to a user&#39;s requirements, each of the phase switching units  40  can be connected to the phased antennas  311  having the same length (shown in  FIG. 4  and  FIG. 5 ), or the phase switching units  40  can be connected to the phased antennas  311  having different lengths (shown in  FIG. 6  to  FIG. 11 ), so that the phased array antenna structure  100  can be used to generate a specific antenna pattern P for the user&#39;s requirements. Accordingly, since “N” is taken as four in the present embodiment, the phased array antenna structure  100  can be used to generate nine different antenna patterns P. The drawings of the present embodiment only show four of the nine different antenna patterns P. 
     In summary, the phased array antenna structure  100  in the present embodiment can be effectively cooperated with the phase switching units  40  by the structural design and the cooperation of the radiative layer  2  and the circuit layer  3 , so that phased array antenna structure  100  of the present embodiment can be formed without the phase shifter that is at least ten times more expensive than the phase switches ( 4 ,  4   a ). 
     Second Embodiment 
     Referring to  FIG. 12  to  FIG. 15 , a second embodiment of the present disclosure is similar to the first embodiment of the present disclosure, so that the descriptions of the same components in the first and second embodiments of the present disclosure will be omitted for the sake of brevity, and the following description only discloses different features between the first and second embodiments. 
     As shown in  FIG. 12  and  FIG. 13 , the present embodiment provides a phased array antenna structure  100  operated in a frequency band that has a center frequency corresponding to a wavelength (i.e., the center frequency is a reciprocal of the wavelength). The phased array antenna structure  100  includes a carrier  1 , a radiative layer  2  and a circuit layer  3  both disposed on the carrier  1 , and N number of phase switch  4  mounted on the carrier  1  and corresponding in position to the circuit layer  3 . The carrier  1  of the present embodiment is similar to that of the first embodiment, so that the description of the carrier  1  in the present embodiment will be omitted for the sake of brevity. 
     The radiative layer  2  includes two radiating portions  21 , and the two radiating portions  21  in the present embodiment have the same shape (e.g., a portion of each of the two radiating portions  21  is in a spiral shape) and are formed on the first surface  11  of the carrier  1 . The circuit layer  3  is formed on the first surface  11  of the carrier  1 . The circuit layer  3  includes a phased antenna  311  connected to the two radiating portions  21  and a transmission circuit  32  arranged adjacent to the phased antenna  311 . 
     Specifically, the phased antenna  311  includes two end portions  3111  respectively connected to the two radiating portions  21 . A length of the phased antenna  311  can be multiples of ¼ of the wavelength, and the length of the phased antenna  311  in the present embodiment is ¼ of the wavelength, but the present disclosure is not limited thereto. Moreover, the phased antenna  311  in the present embodiment is arranged between the two radiating portions  21 . In other embodiments of the present disclosure, the phased antenna  311  can be arranged at the left side or the right side of the transmission circuit  32 . 
     The transmission circuit  32  in the present embodiment is in a substantial straight shape, and has a feeding end  3211  and an externally connecting end  3221  opposite to the feeding end  3211 . The feeding end  3211  is disposed on (or flush with) an edge of the carrier  1 . The feeding circuit  321  extends from the feeding end  3211  to the connecting end  3212  in a direction toward the phased antenna  311 . The externally connecting end  3221  is arranged adjacent to the phased antenna  311 . In other words, the externally connecting end  3221  is spaced apart from the phased antenna  311 . It should be noted that the phased antenna  311  and the radiative layer  2  in the present embodiment are coplanar and are integrally formed as a one-piece structure, and the phased array antenna structure  100  can be in a mirror symmetry with respect to the transmission circuit  32  for being easily manufactured, but the present disclosure is not limited thereto. 
     The phase switch  4  is directly or indirectly connected to the externally connecting end  3221  of the transmission circuit  32 , and the phase switch  4  is configured to selectively connect only one of the two end portions  3111  of the phased antenna  311 , so that the phased array antenna structure  100  can be used to generate two different antenna patterns P (shown in  FIG. 14  and  FIG. 15 ). Specifically, as shown in  FIG. 14  and  FIG. 15 , the phased antenna  311  and one of the two radiating portions  21  are configured to jointly generate a first antenna pattern P, the phased antenna  311  and the other one of the two radiating portions  21  are configured to jointly generate a second antenna pattern P, a phase difference between the first antenna pattern P and the second pattern P is 90 degrees. 
     In conclusion, the phased array antenna structure in the present disclosure can effectively use the phase switching units (or the phase switch) by the structural design and the cooperation of the radiative layer and the circuit layer, so that phased array antenna structure of the present disclosure can be formed without the phase shifter that is at least ten times more expensive than the phase switches. 
     The foregoing description of the exemplary embodiments of the disclosure has been presented only for the purposes of illustration and description and is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Many modifications and variations are possible in light of the above teaching. 
     The embodiments were chosen and described in order to explain the principles of the disclosure and their practical application so as to enable others skilled in the art to utilize the disclosure and various embodiments and with various modifications as are suited to the particular use contemplated. Alternative embodiments will become apparent to those skilled in the art to which the present disclosure pertains without departing from its spirit and scope.