Patent Publication Number: US-9425507-B1

Title: Structure of expandable multi-mode phased-array antenna

Description:
STATEMENT REGARDING SPONSORED RESEARCH AND DEVELOPMENT 
     This work (Project number: B0101-15-1372; Project Name: Development of Mobile Multi-mode Transmission Technology based on Spatial Spreading) was supported by ICT R&amp;D program sponsored by Ministry of Science, ICT and Future Planning (MSIP) of Republic of Korea and Institute for Information and Communication Technology Promotion (IITP) of Republic of Korea. 
    
    
     CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Korean Patent Application No. 2015-0016082, filed on Feb. 2, 2015, the disclosure of which is incorporated herein by reference in its entirety. 
     BACKGROUND 
     1. Field of the Invention 
     The present invention relates to a structure of a multi-mode phased-array antenna which is used for a wireless communication and a radar. 
     2. Discussion of Related Art 
     Recently, since the need to simultaneously track a plurality of targets moving at high speed over long distances has been increased significantly, the use of a phased-array antenna with an accompanying high power phase shifter has been increased significantly. 
     The phase shifter is an apparatus configured to shift the phase of an electromagnetic wave to be transmitted, and is mainly used to adjust a phase of each radiating element of the phased-array antenna electrically steering an antenna beam. 
     The phased-array antenna may be configured with a plurality of radiating elements, a phase shifter, an amplifier, a signal distributor, and the like. This phased-array antenna of the related art is disclosed in Korea Laid-Open Patent Publication No. 2013-0041697. At this time, elements may be connected to each other through RF connectors and cables for signal transmission. 
     Then, since the number of required RF connectors and cables is increased exponentially as the number of elements is increased, the size of the phased-array antenna is increased. In addition, there is problem in that the loss of the phased-array antenna occurs due to the RF connector and cable, and the performance thereof is degraded. Therefore, a phased-array antenna is needed to improve the problem described above and to miniaturize the size thereof. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a phased-array antenna in which a plurality of element antennas and antenna modules are three-dimensionally disposed and perpendicularly coupled to a signal distribution module using connection pins. 
     In addition, the present invention is also directed to the phased-array antenna in which the number of elements thereof is changed easily and a plurality of modes may be implemented since a plurality of signal distributors are horizontally stacked. 
     According to an aspect of the present invention, there is provided a phased-array antenna, including: a plurality of element antennas having feed lines formed thereon; antenna modules configured to extend and be disposed in longitudinal directions of the element antennas and independently connected to one ends of the plurality of element antennas, respectively; and a signal distribution module disposed in a direction perpendicular to the antenna modules, having one sides being perpendicularly connected to each of the antenna modules, and configured to distribute an input signal to the corresponding antenna modules through connection pins whose one sides are respectively connected to the antenna modules. 
     In the signal distribution modules, the number of signal distributors the same as the number of transmission modes to be transmitted by the phased-array antenna may be stacked and screw-coupled. 
     Each of the signal distributors may include a substrate having a signal connector configured to receive the input signal and connection pins which transmit distribution signals distributed from the signal connector to the corresponding antenna modules, and a cover stacked on the substrate to protect and support the substrate, wherein the substrate and cover may be screw-coupled. 
     In the signal distributors, one side of the connection pin formed on the substrate may be coupled to the corresponding antenna module, and the signal connector may pass and be exposed through the cover formed on an outermost side thereof. 
     Locations of the connection pins and the signal connector formed on the substrates of each of the signal distributors may be spaced apart from each other not to overlap vertically. 
     The phased-array antenna may further include a heat pipe, and the plurality of antenna modules may be spaced apart from each other and perpendicularly coupled to an edge of one side of the signal distribution module to form a three-dimensional space, and the heat pipe may pass through the three-dimensional space and the signal distribution module and protrude from an outer side of the signal distribution module. 
     The antenna module may include a phase shifter or a phase shifter and amplifying circuit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and advantages of the present invention will become more apparent to those of ordinary skill in the art by describing in detail exemplary embodiments thereof with reference to the accompanying drawings, in which: 
         FIG. 1  is a view illustrating as phased-array antenna according to an embodiment of the present invention; 
         FIGS. 2 and 3  are perspective views illustrating the phased-array antenna of  FIG. 1 ; 
         FIG. 4  is an exploded perspective view of the phased-array antenna of  FIG. 1 ; 
         FIG. 5  is a cross-sectional view illustrating the phased-array antenna of  FIG. 1 ; 
         FIG. 6  is an exploded perspective view illustrating an antenna module of the phased-array antenna of  FIG. 1 ; 
         FIG. 7  is an exploded perspective view illustrating a signal distribution module of the phased-array antenna of  FIG. 1 ; 
         FIG. 8  is a rear view of a first substrate of  FIG. 7 ; and 
         FIG. 9  is a rear view of a second substrate of  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intent to limit the invention to the particular forms disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like numbers refer to like elements throughout the description of the figures. 
     Like numbers refer to like elements throughout the description of the figures. In detailed descriptions of operation principles of the exemplary embodiments of the invention, when it is determined that detailed descriptions of related well-known functions and configurations unnecessarily obscure the gist of the invention, detailed descriptions thereof will be omitted. 
     It will be understood that, although the terms “first,” “second,” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. 
     For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present invention. 
     As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. 
     In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. 
     As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. 
     It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
     Hereinafter, a phased-array antenna according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings  FIGS. 1 to 9 . In the below description of the present invention, the well-known description of the related art will be omitted or simplified in order to dearly explain the gist of the present invention. 
       FIG. 1  is a view illustrating a phased-array antenna according to an embodiment of the present invention. A phased-array antenna  1000  according to the embodiment of the present invention may include element antennas  100 , antenna modules  200 , a signal distribution module  300 , and a heat pipe  400 , and further include a heat sink  500  on an end of the heat pipe  400 . The phased-array antenna  1000  according to the embodiment of the present invention may be connected to the heat pipe  400  and a direction controller to adjust horizontal rotating and an angle, and vertically movable by a supporter which supports the direction controller, and the supporter may be supported by a stand. 
       FIGS. 2 and 3  are perspective views illustrating the phased-array antenna of  FIG. 1 .  FIG. 4  is an exploded perspective view illustrating the phased-array antenna of  FIG. 1 .  FIG. 5  is a cross-sectional view illustrating the phased-array antenna of  FIG. 1 .  FIG. 6  is an exploded perspective view illustrating an antenna module of the phased-array antenna of  FIG. 1 . 
     An element antenna  100  may be a patch antenna having a feed line formed therein or an arbitrary antenna. The plurality of element antennas  100  may be implemented by binding the plurality to generate a desired transmission mode. 
     An antenna module  200  may extends and be disposed in a longitudinal direction to the element antenna  100 , and may be provided in the same number as the number of element antennas  100 . At this time, the antenna modules  200  may be independently connected to ends of the plurality of element antennas  100 , respectively. 
     Here, the antenna module  200  may include a substrate  210  included in a phase shifter or a phase shifter and amplifying circuit, and an upper case  220  and a lower case  230  housing the substrate  210 . In addition, the upper parts of the cases  220  and  230  may be coupled to the element antenna  100 , and the lower parts of the cases  220  and  230  may be coupled to the signal distribution module  300 . At this time, screw coupling or the like may be used for the coupling. 
     The signal distribution module  300  may be disposed in a direction perpendicular to the antenna module  200 , and one side thereof may be perpendicularly coupled to each of the antenna modules  200 . At this time, a phased-array antenna  1000  may include a first supporter  10  and a second supporter  20  configured to support the antenna module  200  perpendicularly coupled to the signal distribution module  300 . 
     The first supporter  10  may couple the element antenna  100  to the lower case  230  of the antenna module  200  for each channel, and the second supporter  20  may perpendicularly couple the antenna module  200  to the signal distribution module  300 . 
     Here, the shape and the size of the first supporter  10 , the second supporter  20 , and the signal distribution module  300  may be determined by the number of channels of the phased-array antenna. In the embodiment of the present invention, the use of eight channels will be described. In the embodiment of the present invention, since a structure of a multi-mode phased-array antenna using eight channels is described, the first supporter  10 , the second supporter  20 , and the signal distribution module  300  having an octangular shape are disclosed as shown in  FIG. 4 . Meanwhile, this should be simply considered as an embodiment, and a shape and size thereof may be easily changed by a designer when the number of channels is changed. 
     In addition, the antenna module  200  perpendicularly coupled to the signal distribution module  300  may form a three-dimensional space by being perpendicularly coupled to an edge of one side of the signal distribution module  300  with an interval. 
     At this time, a heat pipe  400  may be provided to effectively dissipate heat generated by the antenna module  200 . 
     The heat pipe  400  may be fixed to the first supporter  10 , pass through a through hole  40   h  formed in centers of the three-dimensional space and the signal distribution module  300 , and protrude from an outer side of the signal distribution module  300 . Therefore, the heat generated by the antenna module  200 , and particularly, the amplifying circuit may externally dissipate through the heat pipe  400 , and the effect of heat dissipation may be further enhanced by a heat sink  500 . 
     Meanwhile, the signal distribution module  300  may include at least one of signal distributors  1  and  2 . Here, each of the signal distributors  1  and  2  may include a substrate  320  or  340  forming a signal distribution path and a cover  330  or  350  configured to protect and support the substrate  320  or  340 . In addition, the signal distribution module  300  may further include a connection part  310  configured to connect and support the signal distribution module  300  and the antenna module  200 . 
     The antenna module  200  may be perpendicularly coupled to the signal distribution module  300  in a longitudinal direction. The connection part  310  may be stacked on a bottom of the antenna module  200  and the second supporter  20 . The connection part  310 , substrates  320  and  340 , and covers  330  and  350  may be screw-coupled to bottoms of the cases  220  and  230  of the antenna module  200 . 
     Here, the number of signal distributors  1  and  2  is determined by a transmission mode to be transmitted. That is, in the above case, since one mode is made by binding four element antennas which are alternately sequenced, two modes are made with eight element antennas. Since the number of antenna modules  200  is eight, two signal distributors may be horizontally stacked and screw-coupled to the signal distribution module  300 . In another example, one mode may also be generated using the total of eight element antennas, and in this case, the signal distribution module  300  includes one signal distributor. Thus, the number of modules according to the number of channels may be changed easily, and the sin of the module may be miniaturized, and therefore, the overall size of the phased-array antenna  1000  may also be miniaturized. 
     At this time, the coupling relation of the signal distribution module  300  including the plurality of signal distributors  1  and  2  and the antenna module  200  may be described with reference to  FIGS. 4 to 8 . Here, when one mode is made with four element antennas, two signal distributors  1  and  2  may be provided. 
     Referring to  FIG. 7 , a signal distribution module  300  may include a connection part  310 , a first substrate  320 , a first cover  330 , a second substrate  340 , and a second cover  350 . In addition, the rear surfaces of the first substrate  320  and the second substrate  340  may be shown as  FIGS. 8 and 9 . 
     Signal connectors  322  and  342  configured to receive an input signal and connection pins  321  and  341  configured to transmit a distribution signal distributed from the signal connectors  322  and  342  to a corresponding antenna module  200  may be formed on the first substrate  320  and the second substrate  340 . Here, the input signal may be a high frequency signal in which a signal from a modem is frequency-modulated, amplified, and output. 
     In addition, a plurality of circuit pattern paths configured to distribute signals from the signal connectors  322  and  342  to the antenna module  200  may be provided on the first substrate  320  and second substrate  340 . 
     One side of each of the connection pins  321  and  341  may be connected to the circuit pattern path and the other side thereof may be connected to the corresponding antenna module  200 , and the connection pins  321  and  341  may transmit the distribution signal which is distributed and phase-delayed through the circuit pattern path formed on the substrates to the corresponding antenna module  200 . 
     Accordingly, the lengths of the connection pins  321  and  341  may be varied according to the location of the stacked substrates  320  and  340 . That is, first connection pins  321   a  to  321   d  may have a length from a part coupling to the substrate (phase shifter)  210  of the antenna module  200  to the first substrate  320 , second connection pins  341   a  to  341   d  may have a length from the part coupling to the the substrate  210  of the antenna module  200  to the second substrate  340 . 
     In addition, the connection part  310 , the first substrate  320 , the first cover  330 , the second substrate  340 , and the second cover  350  may include screw-coupling holes  60   h  for mutual coupling, a heat pipe insertion hole  40   h  having a center in which a heat pipe may be inserted and passed through, and holes in which the first connection pins  321   a  to  321   d , the second connection pins  341   a  to  341   d , and the signal connectors  322  and  342  may be inserted and passed through. 
     Accordingly, it is preferable that the locations of the first connection pins  321   a  to  321   d  and the first signal connector  322  formed in the first substrate  320  be spaced apart from the location of the second connection pins  341   a  to  341   d  and the second signal connector  342  formed in the second substrate  340  to not vertically overlap. 
     The covers  330  and  350  may be formed in a cover shape having as certain depth and width so as to protect the signal connectors  322  and  342 , the circuit pattern path, and the like formed on the first substrate  320  and the second substrate  340 . 
     Thus, the phased-array antenna  1000  according to the embodiment of the present invention may combine and use the plurality of signal distributors, the plurality of antenna modules, and the plurality of element antennas for a multimode implementation. At this time, the phased-array antenna  1000  according to the embodiment of the present invention may provide a structure in which a plurality of RF connectors and cables configured to couple each Of the elements is not necessary, that is, the plurality of element antennas  100  and the plurality of antenna modules  200  are three-dimensionally disposed and perpendicularly coupled to the signal distribution module  300  using the connection pins. Therefore, the performance of the phased-array antenna  1000  can be improved by reducing a loss generated from the plurality of RF connectors and cables. 
     As described above, the phased-array antenna according to the embodiment of the present invention has a structure in which the plurality of element antennas and antenna modules are three-dimensionally disposed and perpendicularly coupled to the signal distribution module using connection pins, and therefore, the RF connector and cable configured to couple each of the elements are not necessary. Then, the performance of the phased-array antenna can be improved by reducing a loss. In addition, the size of the phased-array antenna can be miniaturized by decreasing the number of components, and cost can be reduced. 
     In addition, since the signal distribution module is implemented in a structure in which a plurality of signal distributors are horizontally stacked, the number of elements thereof is changed easily, and a plurality of modes can be implemented with the size miniaturized. 
     In addition, the heat generated from the amplifying element of the antenna module can dissipate through the heat pipe. 
     The above-described exemplary embodiments of the present invention are only examples and it will be understood by those skilled in the art that various modifications, alternations, and additions may be made without departing from the spirit and scope of the invention. Therefore, the modifications, alternations, and additions fall within the scope of the accompanying claims of the present invention.