Abstract:
The present invention provides a multi-port amplifier which adopts a pair of SP4T switches and a pair of hybrid couplers in order to flexibly adjust an amplification mode. By using the proposed invention, the limited system flexibility and reconfigurability due to fixed input and output relations are overcome regardless of a component failure in a system. Moreover, signal amplification based on effective signal distribution and combination can be consistently performed according to various port configurations by different switching modes. Thus, the overall practicality of outputs comparing to the conventional multi-port amplifier can be effectively increased within an available lifespan of the system.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to and the benefit of Korean Patent Application No. 10-2014-0025436 filed in the Korean Intellectual Property Office on Mar. 4, 2014, the entire contents of which are incorporated herein by reference. 
       TECHNICAL FIELD 
       [0002]    The present invention relates to a multi-port amplifier and a method for controlling the same, and particularly, to a multi-port amplifier which improves a selectivity of an output port by flexibly controlling a switching mode of a hybrid matrix and a method for controlling the same. 
       BACKGROUND ART 
       [0003]    A multi-port amplifier (MPA) is an apparatus or a device which is used for a communication satellite transponder to perform an output power controlling function. A general multi-port amplifier has a structure which applies a signal through an input port which is determined by a fixed input/output matrix and then obtains a desired signal through a determined output port so that there is a limitation in adjustment of a flexible signal flow between an input and an output. That is, the input/output port of the general multi-port amplifier is determined by an input/output matrix and the determined input and output relations are changed only by an operation of a phase shifter of a signal path. Further, in the case of four ports, only four methods are applicable to the relations. 
         [0004]    A general multi-port amplifier is configured by connecting a plurality of hybrid couplers such as a butler matrix. Further, even though input signals are distributed or combined by distributing and combining the signals in accordance with a phase and an amplitude of a signal which passes through the coupler, the general multi-port amplifier is implemented by combining couplers, which are a passive element, so that a flow of the input/output signal is fixed. Therefore, in the multi-port amplifier system which shares a plurality of high power amplifiers (HPA) through an input/output matrix, when one high power amplifier fails or one signal path in arrays of several flows fails, the signals may not be smoothly combined or distributed so that performance of the entire system is degraded. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention has been made in an effort to provide a multi-port amplifier in which a switch such as a single-pole four throw (SP4T) is applied to a hybrid matrix to output outputs having various phases and amplitudes, which are effectively distributed and combined according to a switching mode, through an output port and a method for controlling the same. 
         [0006]    An exemplary embodiment of the present invention provides a multi-port amplifier including multiple input terminals and multiple output terminals, including: one or more matrix cells of two inputs-two outputs type to distribute and combine signals, wherein each matrix cell comprises two switching units which operate in switching modes including an open-circuit mode, a short-circuit mode, an inductor connection mode, or a capacitor connection mode in accordance with a control signal, respectively; and two hybrid units which are combined between the two switching units and receive each of input signals and synthesize input signals to generate synthesized output signals. 
         [0007]    The multi-port amplifier may further include amplifiers which amplify output signals of the one or more matrix cells respectively. 
         [0008]    The multi-port amplifier may further include one or more second matrix cells which have the same configuration as the one or more matrix cells to distribute and combine outputs of the amplifiers. 
         [0009]    Each of the one or more matrix cells and each of the one or more second matrix cells further may include a second matrix cell with the same configuration as the matrix cell, and the matrix cell and the second matrix cell may be connected in a cascaded manner. 
         [0010]    The one or more matrix cells and the one or more second matrix cells may further include three matrix cells with the same configuration as the matrix cell to form first to fourth matrix cells, and one of two outputs of the first matrix cell and the second matrix cell may be input to the third matrix cell respectively and the other output may be input to the fourth matrix cell respectively. 
         [0011]    The switching unit may provide an impedance of ∞ in the open-circuit mode, an impedance of zero in the short-circuit mode, an impedance of +j25Ω in the inductor connection mode, and an impedance of −j25Ω in the capacitor connection mode. 
         [0012]    The multi-port amplifier may be applied in order to distribute and combine transmission/reception signals in a multi beam antenna system, a communication and broadcasting satellite payload system, or a satellite transponder. 
         [0013]    The switching unit may include a single-pole four throw (SP4T) switch. 
         [0014]    The hybrid unit may include a 3-dB coupler. 
         [0015]    Another exemplary embodiment of the present invention provides method for controlling a multi-port amplifier including multiple input terminals and multiple output terminals, the method including: in each of one or more two inputs-two outputs matrix cells to distribute and combine signals, (A) operating, by two switching units, in switching modes including an open-circuit mode, a short-circuit mode, an inductor connection mode, and a capacitor connection mode in accordance with a control signal respectively; and (B) receiving, by two signal synthesizing units which are combined between the two switching units, each of input signals, synthesizing input signals and generating synthesized output signals. 
         [0016]    The method may further include amplifying the output signals to generate amplified signals respectively. 
         [0017]    The method may further include distributing and combining, by one or more second matrix cells with the same configuration as the one or more matrix cells, the amplified signals. 
         [0018]    The one or more matrix cells and the one or more second matrix cells may distribute and combine the signals further using a second matrix cell which has the same configuration as the matrix cell which performs steps (A) and (B) and is connected in a cascaded manner. 
         [0019]    The one or more matrix cells and the one or more second matrix cells may further include three matrix cells with the same configuration as the matrix cell, which perform steps (A) and (B), to form first to fourth matrix cells, and one of two outputs of the first matrix cell and the second matrix cell may be input to the third matrix cell respectively and the other output may be input to the fourth matrix cell respectively. 
         [0020]    The switching unit may provide an impedance of ∞ in the open-circuit mode, an impedance of zero in the short-circuit mode, an impedance of +j25Ω in the inductor connection mode, and an impedance of −j25Ω in the capacitor connection mode. 
         [0021]    The multi-port amplifier may be applied in order to distribute and combine transmission/reception signals in a multi beam antenna system, a communication and broadcasting satellite payload system, or a satellite transponder. 
         [0022]    The switching unit may include a single-pole four throw (SP4T) switch. 
         [0023]    The synthesizing unit may include a 3-dB coupler. 
         [0024]    According to a multi-port amplifier and a method for controlling the same according to the exemplary embodiment of the present invention, a switch such as an SP4T is applied to the hybrid matrix in order to adjust an output mode setting so that a limitation in system flexibility and reconstruction due to fixed input and output relations is overcame. Further, even though failure or a problem occurs in an amplifier of the system or other circuit configurations in accordance with a usage circumstance, the amplifier or other circuit configurations may be continuously used with a port configuration by effective signal distribution and combination in accordance with a switching mode, thereby increasing an availability of an output by twice or more a conventional multi-port amplifier and prolonging an available lifespan of the system. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]      FIG. 1  is a diagram of a multi-port amplifier according to an exemplary embodiment of the present invention. 
           [0026]      FIG. 2A  is a diagram of a matrix cell of  FIG. 1 . 
           [0027]      FIG. 2B  is a view illustrating a switching unit of  FIG. 2A . 
           [0028]      FIG. 3  is a view illustrating an example of an output option when the matrix cells of  FIG. 1  are connected in a cascaded manner. 
           [0029]      FIG. 4  is a view illustrating an operation of hybrid matrices of  FIG. 1 . 
           [0030]      FIG. 5  is a flowchart illustrating a method for controlling a multi-port amplifier according to an exemplary embodiment of the present invention. 
       
    
    
       [0031]    It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment. 
         [0032]    In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing. 
       DETAILED DESCRIPTION 
       [0033]    Hereinafter, the present invention will be described in detail with reference to accompanying drawings. In this case, like components are denoted by like reference numerals in the drawings, if possible. Further, a detailed description of a function and/or a configuration which has been already publicly known will be omitted. In the following description, parts which are required to understand an operation according to various exemplary embodiments will be mainly described and a description on components which may cloud a gist of the description will be omitted. 
         [0034]    Some components of the drawings may be exaggerated, omitted, or schematically illustrated. However, a size of the component does not completely reflect an actual size and thus the description is not limited by a relative size or interval of the components illustrated in the drawings. 
         [0035]      FIG. 1  is a diagram of a multi-port amplifier  10  according to an exemplary embodiment of the present invention. 
         [0036]    As illustrated in  FIG. 1 , the multi-port amplifier  10  includes an input hybrid matrix  100 , an amplifying unit  200 , and an output hybrid matrix  300 . 
         [0037]    As will be described below with reference to  FIG. 2 , the input hybrid matrix  100  and the output hybrid matrix  300  may include four two inputs-two outputs matrix cells  110  which are unit switching mode hybrid matrix (SMHM) cells, respectively. As will be described below, each matrix cell  110  may operate in various switching modes (for example, an open-circuit mode (impedance ∞), a short-circuit mode (impedance 0), an inductor connection mode (impedance +j25Ω), and a capacitor connection mode (impedance −j25Ω)) in order to effectively distribute and combine signals, and output output signals Out 1 , Out 2 , Out 3 , and Out 4  having various phases and amplitudes through an output terminal with respect to input signals IN 1 , IN 2 , IN 3 , and IN 4  which are input to an input terminal by various combination thereof. 
         [0038]    The multi-port amplifier  10  may include a plurality of input terminals and a plurality of output terminals in which the number of input terminals and output terminals is 2 n  (here, n is a natural number). Therefore, the multi-port amplifier  10  having 2, 4, 8, 16, . . . input/output terminals may be configured and may have various configurations depending on a design of a designer in consideration of an implementation availability or an optimal performance. 
         [0039]    That is, for the 4×4 (four inputs-four outputs) multi-port amplifier  10 , the input hybrid matrix  100  is configured by a plurality of matrix cells  110  (# 1 , # 2 , # 3 , and # 4 ) and two outputs ports of the matrix cell # 1  are connected to input ports of the matrix cells # 3  and # 4 , respectively. Further, two output ports of the matrix cell # 2  are connected to the input ports of the matrix cell # 3  and # 4 , respectively. However, for the 2×2 multi-port amplifier, when the matrix cells # 2  and # 4  are not provided, two output ports of the matrix cell # 1  may be connected to two input ports of the matrix cell # 3 . In accordance with a configuration of the system, the input hybrid matrix  100  may be configured by one matrix cell  110  or may include more matrix cells  110 . 
         [0040]    In  FIG. 1 , the hybrid matrix  100  distributes and combines input signals IN 1 , IN 2 , IN 3 , and IN 4  in accordance with an operation corresponding to a switching mode of the plurality of matrix cells  100  (# 1 , # 2 , # 3 , and # 4 ) and outputs corresponding synthesized (distributed and combined) signals to the amplifying unit  200  (see step S 510  of  FIG. 5 ). 
         [0041]    The amplifying unit  200  amplifies the synthesized signals, which are output at a predetermined frequency band through four output ports of the input hybrid matrix  100 , using drive amplifiers DAs to output corresponding amplified signals to the output hybrid matrix  300  (see step S 520  of  FIG. 5 ). 
         [0042]    Similarly to the configuration of the input hybrid matrix  100  described above, a configuration of the output hybrid matrix  300  is configured by a plurality of matrix cells  110  # 5 , # 6 , # 7 , and # 8  and two output ports of the matrix cell # 5  are connected to input ports of matrix cells # 7  and # 8 , respectively. Further, two output ports of the matrix cell # 6  are connected to the input ports of matrix cells # 7  and # 8 , respectively. However, for the 2×2 multi-port amplifier, when the matrix cells # 6  and # 8  are not provided, two output ports of the matrix cell # 5  may be connected to two input ports of the matrix cell # 7 . Further, in accordance with a configuration of the system, the output hybrid matrix  300  may be configured by one matrix cell  110  or may include more matrix cells  110 . 
         [0043]    The output hybrid matrix  300  distributes and combines four output signals of the amplifying unit  200  in accordance with an operation corresponding to switching modes of the plurality of matrix cells  110  (# 5 , # 6 , # 7 , and # 8 ) and outputs corresponding synthesized (distributed and combined) signals Out 1 , Out 2 , Out 3 , and Out 4  having various phases and sizes through an output port (see step S 530  of  FIG. 5 ). 
         [0044]    The multi-port amplifier  10  according to the exemplary embodiment of the present invention may be used to distribute and combine transmission/reception signals in a multi beam antenna system (not illustrated). That is, a multi beam antenna system which provides a narrow beam having a high antenna gain in a service coverage is used for a communication and broadcasting satellite payload system due to excellent effective isotropic radiated power (EIRP) and a gain-to-noise (G/T) performance. 
         [0045]    The multi-port amplifier  10  according to the exemplary embodiment of the present invention, which may control an output power in accordance with an operational condition, may be used in a multi beam antenna system. Further, the multi beam antenna system which uses the multi-port amplifier  10  according to the exemplary embodiment of the present invention may provide several spot beams in a service area to provide a communication and broadcasting service and further flexibly provide a high power allocation in an area which requires a higher EIRP due to rainfall or sudden increase of a communication service. Further, when high power amplifiers having the highest failure rate among components for a satellite transponder are used to be connected in parallel, if the multi-port amplifier  10  according to the exemplary embodiment of the present invention is used, a less number of high power amplifier redundancies than a conventional satellite transponder may be used to configure the system. 
         [0046]    In the antenna system to which the multi-port amplifier  10  according to the exemplary embodiment of the present invention is applied, an RF power which is allocated to one beam may form a part (1:N) of whole available RF power rather than one to one relation with one high power amplifier HPA (DA). For example, the high power drive amplifier DA of the amplifying unit  200  receives an output signal of the input hybrid matrix  100  to amplify the output signal with an appropriately distributed power and the amplified signals may be used to create a signal required to form individual beams by the output hybrid matrix  300 . By doing this, as compared with a case when one high power amplifier is used for every beam to amplify a signal, according to the exemplary embodiment of the present invention, a plurality of high power drive amplifiers DA of the amplifying unit  200  effectively distributes and combines an amplifying signal so that a size of the output is flexibly adjusted and a load of the high power amplifier is reduced. Further, in some cases, a maximum output power of each of the high power drive amplifiers DAs is used to appropriately use the entire available RF power so as to be flexibly allocated to form the antenna beam. 
         [0047]      FIG. 2A  is a diagram of the matrix cell  110  of  FIG. 1 . 
         [0048]    Referring to  FIG. 2A , the plurality of matrix cells  110  (# 1 , # 2 , # 3 , and # 4 ) of the input hybrid matrix  100  and the plurality of matrix cells  110  (# 5 , # 6 , # 7 , and # 8 ) of the output hybrid matrix  300  are configured by two switching units  111  and two hybrid units (signal synthesizing unit)  112  combined between the switching units  111 . 
         [0049]    The switching unit  111  may be a single-pole four throw (SP4T) switch and as illustrated in  FIG. 2B , may operate in various switching modes (for example, an open-circuit mode (impedance ∞), a short-circuit mode (impedance 0), an inductor connection mode (impedance +j25Ω), and a capacitor connection mode (impedance −j25Ω)) in accordance with a control signal of a control unit (not illustrated) to provide a load impedance in accordance with the corresponding mode. 
         [0050]    The two hybrid units  112  may be 3-dB couplers and receive an input signal (for example, an RF signal) through input ports P 1 /P 2  which are connected to each unit  112  in accordance with the corresponding load impedance which is provided in accordance with the switching mode of the switching unit  111 , and synthesize the received signals in accordance with the combined structure to create synthesized output signals and output the output signals through the output ports P 3 /P 4 . 
         [0051]    For example, when P 1 , P 2 , P 3 , and P 4  are used as input ports P 1  (for example, a voltage V 1 ), an isolation port P 2  (for example, a voltage V 2 =0), output ports P 3  and P 4  (for example, voltages V 3  and V 4 ) and there are no reflected signals from the input port P 1  and the isolation port P 2 , the following Equation 1 may be obtained. 
         [0000]    
       
         
           
             
               
                 
                   
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         [0052]    In Equation 1, when a signal is applied only to the input port P 1  (V 2 +=0), Equations 2 and 3 are obtained, and finally a relation between the output signals may be represented by Equation 4. 
         [0000]    
       
         
           
             
               
                 
                   
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         [0053]    Here, x is a corresponding load impedance according to the switching mode (for example, an open-circuit mode (impedance ∞), a short-circuit mode (impedance 0), an inductor connection mode (impedance +j25Ω), and a capacitor connection mode (impedance −j25Ω)) of the switching unit  111 , and Z 0  is a characteristic impedance of corresponding transmission line. 
         [0054]    In this case, for example, in the open-circuit mode (x=∞) of the two switching units  111 , the matrix cell  110  may output the output signal only to the port P 3 . Further, in the short-circuit mode (x=0) of the two switching units  111 , the matrix cell  110  may output the output signal only to the port P 4 . 
         [0055]    In order to distribute the input signal to the ports P 3  and P 4  so as to have the same size, a condition of |j2×|=|Z 0 | needs to be satisfied so that if ωL=Z 0 /2 (in an inductor L connection mode of the two switching units  111 ), a phase difference between signals of the ports P 3  and P 4  is 90 degree, and if ωC=Z 0 /2 (in a capacitor C connection mode of the two switching units  111 ), a phase difference between signals of the ports P 3  and P 4  is −90 degree. 
         [0056]    When a signal is applied to the input ports P 1  and P 2 , output options of output ports P 3  and P 4  in the matrix cell  110  in accordance with the operation of the hybrid unit  112  according to the switching modes of the switching unit  111  will be represented in the following Table 1. 
         [0000]    
       
         
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 Switch Mode 
                   
                   
                   
                   
               
               
                 (load 
                 Mode 1: 
                 Mode 2: 
                 Mode 3: 
                 Mode 4: 
               
               
                 impedance) 
                 (open) 
                 (short) 
                 (+j25Ω) 
                 (−j25Ω) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Input to P 1   
                 Output P 3   
                 1 
                 0 
                 
                   
                     
                       
                         
                           - 
                           j 
                         
                         
                           2 
                         
                       
                     
                   
                 
                 
                   
                     
                       
                         1 
                         
                           2 
                         
                       
                     
                   
                 
               
               
                   
               
               
                   
                 Output P 4   
                 0 
                 1 
                 
                   
                     
                       
                         1 
                         
                           2 
                         
                       
                     
                   
                 
                 
                   
                     
                       
                         
                           - 
                           j 
                         
                         
                           2 
                         
                       
                     
                   
                 
               
               
                   
               
               
                 Input to P 2   
                 Output P 3   
                 0 
                 1 
                 
                   
                     
                       
                         1 
                         
                           2 
                         
                       
                     
                   
                 
                 
                   
                     
                       
                         
                           - 
                           j 
                         
                         
                           2 
                         
                       
                     
                   
                 
               
               
                   
               
               
                   
                 Output P 4   
                 1 
                 0 
                 
                   
                     
                       
                         
                           - 
                           j 
                         
                         
                           2 
                         
                       
                     
                   
                 
                 
                   
                     
                       
                         1 
                         
                           2 
                         
                       
                     
                   
                 
               
               
                   
               
             
          
         
       
     
         [0057]    As described above, by providing the load impedance according to the switching mode (for example, an open-circuit mode (impedance ∞), a short-circuit mode (impedance 0), an inductor connection mode (impedance +j25Ω), and a capacitor connection mode (impedance −j25Ω)) of the switching unit  111 , the hybrid unit  112  may output various types of input signals to the output ports P 3  and P 4 . 
         [0058]      FIG. 3  is a view illustrating an example of an output option when two or more matrix cells  110  of  FIG. 1  are connected in a cascaded manner. 
         [0059]    As illustrated in  FIG. 3 , the matrix cell  110  may output two input signals as four distributed and combined signals according to the switching mode of the switching unit  111  as represented in Equation 4 and generate another four distributed and combined signals with the two outputs of the matrix cell  110  as two inputs of another matrix cell  110  to output various output signals having four cases of signal amplitudes and phases. 
         [0060]    In the meantime, in  FIG. 1 , the input hybrid matrix  100  or the output hybrid matrix  300  may output output signals  01 ,  02 ,  03 , and  04  having various phases and amplitudes through the output port by various combinations through effective distribution and combination for input signals I 1 , I 2 , I 3 , and I 4 , as illustrated in  FIG. 4 , in accordance with operations according to the switching modes of the matrix cells  110 . The following Table 2 is a table exemplifying signals  01 ,  02 ,  03 , and  04  which are output when a signal is applied to an input port  1  ( 11 ) of the matrix cell  110  (# 1 ) in the case when the switching units  111  of the cells  110  # 1  and # 2  among the matrix cells  110  (# 1 , # 2 , # 3 , and # 4 ) of the input hybrid matrix  100  are in the same switching mode and the switching units  111  of the cells  110  # 3  and # 4  are in the same switching mode. 
         [0061]    Even though all cases for all input ports  11 ,  12 ,  13 , and  14  are not exemplified in Table 2, the same result as Table 2 may be output for corresponding inputs of the input ports due to a circuit symmetry in each cell  110 . 
         [0000]    
       
         
               
               
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
             
             
               
                 SMHM 
                 #4 Mode1: 
                 #4 Mode2: 
                 #4 Mode3: 
                 #4 Mode4: 
               
               
                 # 
                 (open) 
                 (short) 
                 (+j25 Ω) 
                 (−j25 Ω) 
               
               
                 #3 Mode1: 
                 o 1  = 1 
                 o 2  = 1 
                 o 2  = −j/{square root over (2)}, 
                 o 2  = 1/{square root over (2)}, 
               
               
                 (open) 
                   
                   
                 o 1  = 1/{square root over (2)} 
                 o 1  = −j/{square root over (2)} 
               
               
                 #3 Mode2: 
                 o 3  = 1 
                 o 4  = 1 
                 o 4  = −j/{square root over (2)}, 
                 o 4  = 1/{square root over (2)}, 
               
               
                 (short) 
                   
                   
                 o 3  = 1/{square root over (2)} 
                 o 3  = −j/{square root over (2)} 
               
               
                 #3 Mode3: 
                 o 3  = −j/{square root over (2)}, 
                 o 4  = −j/{square root over (2)}, 
                 o 4  = −1/2, o 3  = −j/2 
                 o 4  = −j/{square root over (2)}, o 3  = −1/2 
               
               
                 (+j25 Ω) 
                 o 1  = 1/{square root over (2)} 
                 o 2  = 1/{square root over (2)} 
                 o 2  = −j/2, o 1  = 1/2 
                 o   2    = 1/2, o 1  −j/2 
               
               
                 #3 Mode4: 
                 o 3  = 1/{square root over (2)}, 
                 o 4  = 1/{square root over (2)}, 
                 o 4  = −j/2, o 3  = 1/2 
                 o 4  = 1/2, o 3  = −j/2 
               
               
                 (−j25 Ω) 
                 o 1  = −j/{square root over (2)} 
                 o 2  = −j/{square root over (2)} 
                 o 2  = −1/2, o 1  = −j/2 
                 o 2  = −j/2, o 3 = −1/2 
               
               
                 SMHM 
                 #2 Mode1: 
                 #2 Mode2: 
                 #2 Mode3: 
                 #2 Mode4: 
               
               
                 # 
                 (open) 
                 (short) 
                 (+j25 Ω) 
                 (−j25 Ω) 
               
               
                   
               
             
          
         
       
     
         [0062]    When an input signal is applied to the IN 4  input terminal, among the multi input terminals of the 4×4 multi-port amplifier  10  illustrated in  FIG. 1 , as represented in the following Table 3, signals which are distributed and combined to be amplified are output to one output terminal (single Out 1 ), two output terminals (dual Out 1  and Out 2 ) or four output terminals (quad Out 1 , Out 2 , Out 3 , and Out 4 ) using all of the matrix cells  110  (# 1 , # 2 , # 3 , and # 4 ) of the input hybrid matrix  100 , the matrix cells  110  (# 5 , # 6 , # 7 , and # 8 ) of the output hybrid matrix  300 , and four drive amplifiers DAs of the amplifying unit  200 . A reference single Ref. single of Table 3 is an example when one drive amplifier is used to transmit a signal to one output terminal Out 1  and is an example when only one genuine drive amplifier including an insertion loss of the input hybrid matrices  100  and  200  is used. 
         [0000]    
       
         
               
               
               
             
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE 3 
               
             
             
               
                   
                   
               
               
                   
                 Switched-impedance corresponding to unit-SMHM 
                 Used 
               
             
          
           
               
                   
                 #1 
                 #2 
                 #3 
                 #4 
                 #5 
                 #6 
                 #7 
                 #8 
                 DA #&#39;s 
               
               
                   
                   
               
             
          
           
               
                 Single: 
                 +j25 Ω 
                 +j25 Ω 
                 +j25 Ω 
                 +j25 Ω 
                 +j25 Ω 
                 +j25 Ω 
                 +j25 Ω 
                 +j25 Ω 
                 1, 2, 
               
               
                 Out 1 
                   
                   
                   
                   
                   
                   
                   
                   
                 3, 4 
               
               
                 Dual: 
                 +j25 Ω 
                 +j25 Ω 
                 +j25 Ω 
                 +j25 Ω 
                 +j25 Ω 
                 +j25 Ω 
                 open 
                 open 
                 1, 2, 
               
               
                 Out 1, 2 
                   
                   
                   
                   
                   
                   
                   
                   
                 3, 4 
               
               
                 Quad: Out 
                 +j25 Ω 
                 +j25 Ω 
                 +j25 Ω 
                 +j25 Ω 
                 open 
                 open 
                 open 
                 open 
                 1, 2, 
               
               
                 1, 2, 3, 4 
                   
                   
                   
                   
                   
                   
                   
                   
                 3, 4 
               
               
                 Ref. 
                 open 
                 open 
                 open 
                 open 
                 short 
                 short 
                 short 
                 short 
                 1 
               
               
                 Single: Out1 
               
               
                   
               
             
          
         
       
     
         [0063]    As described above, in the multi-port amplifier  10  according to the exemplary embodiment of the present invention, in order to adjust the output mode setting, the multi-port amplifier  10  including a matrix cell  110 , which operates in various switching modes by an SP4T switch, is provided so that limitation in system flexibility and reconstruction due to fixed input and output relations is overcame. Further, even though failure or a problem occurs in an amplifier of the system or other circuit configurations in accordance with a usage circumstance, the amplifier or other circuit configurations may be continuously used with a port configuration by effective distribution and combination according to a switching mode, thereby increasing an availability of an output by twice or more a conventional multi-port amplifier and prolonging an available lifespan of the system. 
         [0064]    The present invention has been described with reference to specified matters and limited exemplary embodiments and drawings such as specific elements for general understanding of the present invention, but the present invention is not limited to the exemplary embodiments, and various modifications and changes are possible by those skilled in the art without departing from an essential characteristic of the present invention. Therefore, the spirit of the present invention is defined by the appended claims rather than by the description preceding them, and all changes and modifications that fall within metes and bounds of the claims, or equivalents of such metes and bounds are therefore intended to be embraced by the range of the spirit of the present invention.