Patent Publication Number: US-7907413-B2

Title: Power amplification device and transmitter using it

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a division of and claims the benefit of priority under 35 U.S.C. §120 from U.S. Ser. No. 12/352,787 filed Jan. 13, 2009, and claims the benefit of priority under 35 U.S.C. §119 from Japanese Patent Application No. 2008-41370 filed Feb. 22, 2008, the entire contents of each of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a power amplification device making it possible to simplify a connecting mechanism for a distributor and a synthesizer, and a transmitter using the power amplification device. 
     BACKGROUND 
     A solid-state transmitter that is a transmitter using a semiconductor is characteristic of a small output per unit. Therefore, multiple solid-state transmitters are used in combination in order to provide a desired output power. 
     However, when multiple solid-state transmitters are combined, a transmitter body gets larger. 
     From this viewpoint, a technology for decreasing the size of the transmitter body by arranging the solid-state transmitters on the front side of a housing and the rear side thereof has been proposed (refer to, for example, JP-A-9-275350). 
     However, the above technology has failed to fully downsize the housing. This is attributable to the complexity in the connecting structure for use in connecting the solid-state transmitters to a distributor and a synthesizer alike. 
       FIG. 4A  to  FIG. 4C  show a conventional power amplification unit  10 A.  FIG. 4A  is a front view of the conventional power amplification unit  10 A,  FIG. 4B  is a bottom view of an assembly of the conventional power amplification units  10 A, and  FIG. 4C  is a back view of the conventional power amplification unit  10 A. 
     As shown in  FIG. 4A  to  FIG. 4C , the conventional power amplification unit  10 A has an input connector  14  located by the side of an input terminal  13 A, and has an output connector  15  located by the side of an output terminal  12 A. 
     When a heat sink  16  is abutted on the heat radiation surfaces of the power amplification units  10 A, one input connector  14  and one output connector  15  are, as shown in  FIG. 4B , disposed on the right and left side of the assembly of the power amplification units. 
       FIG. 5  is a bottom view of a transmitter using the conventional power amplification unit  10 A. As shown in  FIG. 5 , an input line  31  led from a distributor  22 A and an output line  32  fed to a synthesizer  21 A intersect each other. Since this wiring is needed, a space for the wirings has to be preserved. This wiring hinders downsizing of the transmitter body. 
     SUMMARY 
     In an aspect of the present invention, the power amplification device includes: a first power amplification unit including a first power amplifier whose heat radiation surface, input terminal, and output terminal have a certain positional relationship, a first input connector disposed by the side of the first output terminal of the first power amplifier, a first output connector disposed by the side of the first input terminal of the first power amplifier, a first output lead that connects the first output terminal and first output connector, and a first input lead that connects the first input terminal and first input connector; a second power amplification unit including a second power amplifier whose heat radiation surface, input terminal, and output terminal have the same positional relationship as that of the first power amplifier, a second output connector disposed by the side of the second output terminal of the second power amplifier, a second input connector disposed by the side of the second input terminal of the second power amplifier, a second output lead that connects the second output terminal and second output connector, and a second input lead that connects the second input terminal and second input connector; and a heat sink that has a first flank thereof abutted on the heat radiation surface of the first power amplification unit and has a second flank thereof abutted on the heat radiation surface of the second power amplification unit. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a front view of a first power amplification unit; 
         FIG. 1B  is a front view of a second power amplification unit; 
         FIG. 1C  is a bottom view of a power amplification device; 
         FIG. 1D  is an A-A sectional view of the power amplification unit shown in  FIG. 1A ; 
         FIG. 2  is a bottom view of a transmitter using the power amplification device of an embodiment of the present invention; 
         FIG. 3  is a sectional view of connectors employed in the embodiment; 
         FIG. 4A  is a front view of a conventional power amplification unit; 
         FIG. 4B  is a bottom view of an assembly of the conventional power amplification units; 
         FIG. 4C  is a back view of the conventional power amplification unit; and 
         FIG. 5  is a bottom view of a transmitter using the conventional power amplification unit. 
     
    
    
     DETAILED DESCRIPTION 
     Throughout this description, the embodiments and examples shown should be considered as exemplars, rather than limitations on the apparatus and methods of the present invention. 
     Referring to the drawings, an embodiment of a power amplification device in accordance with the present invention and a transmitter using the power amplification device will be described below. In the drawings, the same reference numerals are assigned to the same components. An iterative description will be omitted. 
       FIG. 1A  to  FIG. 1D  show a power amplification device  1  of the present embodiment.  FIG. 1A  is a front view of a first power amplification unit  10 .  FIG. 1B  is a front view of a second power amplification unit  17 .  FIG. 1C  is a bottom view of the power amplification device  1 .  FIG. 1D  is an A-A sectional view of the power amplification unit shown in  FIG. 1A . 
     As shown in  FIG. 1A  to  FIG. 1C , the power amplification device  1  includes the first power amplification unit  10 , the second power amplification unit  17 , and a heat sink  16 . 
     The first power amplification unit  10  has an input connector  151  disposed by the side of an output terminal of a first power amplifier  111 , and has an output connector  141  disposed by the side of an input terminal  13  of the first power amplifier  111 . 
     In the first power amplification unit  10 , a first input cable  131  connecting the input terminal  13  and input connector  151  intersects a first output cable  121  connecting the output terminal  12  and output connector  141 . 
     The second power amplification unit  17  has an output connector  142  disposed by the side of an output terminal  18  of a second power amplifier  112 , and has an input connector  152  by the side of an input terminal  19  of the second power amplifier  112 . 
     In the second power amplification unit  17 , a second input cable  191  connecting the input terminal  19  and input connector  152  does not intersect a second output cable  181  connecting the output terminal  18  and output connector  142 . 
     Preferably, the first power amplifier  111  and second power amplifier  112  are identical to each other so that the output signals thereof will be in phase with each other. 
     The first input cable  131  and second input cable  191  have nearly the same length so that the input signals of the first and second power amplifiers will be in phase with each other. If a phase shifter is connected on the second input cable  191 , the first input cable  131  and second input cable  191  may have mutually different lengths. 
     The first output cable  121  and second output cable  181  have nearly the same length so that the output signals of the first and second power amplifiers will be in phase with each other. If a phase shifter is connected on the second output cable  181 , the first output cable  121  and second output cable  181  may have mutually different lengths. 
     In the present embodiment, for power amplification, the phases of signals passing through the first power amplification unit  10  and the second power amplification unit  17  have to be equal to each other. The first power amplifier  111  and the second power amplifier  112  are realized with identical power amplifiers, the phases of signals passing over the first input cable  131  and the second input cable  191  are squared with each other, and the phases of signals passing over the first output cable  121  and the second output cable  181  are squared with each other, whereby the phases of signals passing through the first power amplification unit  10  and the second power amplification unit  17  become equal to each other. 
     The heat sink  16  has the first flank thereof abutted on the heat radiation surface of the first power amplification unit  10 , and has the second flank thereof abutted on the heat radiation surface of the second power amplification unit  17 . 
     As shown in  FIG. 1C , on the bottom of the power amplification device  1 , the input connector  151  of the first power amplification unit  10  and the input connector  152  of the second power amplification unit  17  are disposed by the side of the right flank of the power amplification device  1 . The output connector  141  of the first power amplification unit  10  and the output connector  142  of the second power amplification unit  17  are disposed by the side of the left flank of the power amplification device  1  opposed to the right flank thereof. 
     As shown in  FIG. 1D , the first power amplification unit  10  has the first power amplifier  111  incorporated in a housing thereof. The first power amplifier  111  has a power amplification circuit  115  and a heat radiation panel  116 . The heat radiation panel  116  is in contact with the heat radiation surface  117 . 
     Heat generated by the power amplification circuit  115  is transmitted to the heat radiation panel  116 , transmitted to the heat sink  16  through the heat radiation surface  117 , and radiated from the heat sink  16 . 
     A B-B sectional view of the second power amplification unit  17  shown in  FIG. 1B  is the vertical reverse of the one of  FIG. 1D . 
       FIG. 2  is a bottom view of a transmitter  2  using the power amplification device  1  of the present embodiment. As shown in  FIG. 2 , the transmitter  2  includes multiple power amplification devices  1 , a distributor  22  directly coupled to the input connectors of the multiple power amplification devices  1 , and a synthesizer  21  directly coupled to the output connectors of the multiple power amplification devices  1 . 
     The multiple power amplification devices  1  are directly connected to the distributor  22  and synthesizer  21  through the connectors without use of any cable. 
       FIG. 3  is a sectional view of connectors employed in the present embodiment. As shown in  FIG. 3 , the connectors include a female connector  210  and a male connector  220 . 
     The female connector  210  is shielded with a dielectric  211 , and includes a female center conductor  212  that has a notch, of which section is shaped like a letter V, formed at the end thereof, and a metallic female joint body  213  that is formed outside the dielectric  211  and has a notch, of which section is shaped like a letter V, formed therein. 
     The male connector  220  is shielded with a dielectric  221 , and includes a male center conductor  222  having the end part thereof sharpened so that the section of the end part will be shaped like a letter V, and a metallic male joint body  223  that is formed outside the dielectric  221  and has the end part thereof sharpened so that the section of the end part will be shaped like a letter V. 
     The female connector  210  is attached to the power amplification device  1 , and the male connector  220  is attached to each of the synthesizer  21  and distributor  22 . For connection of the power amplification device  1  to the distributor  22  and synthesizer  21  alike, the male connector  220  is fitted into the female connector  210 . Thus, the power amplification device is directly connected to the distributor  22  and synthesizer  21  alike without use of a cable. 
     As mentioned above, the power amplification device of the present embodiment includes the first power amplification unit  10  having the positions of the connectors thereof reversed, the second power amplification unit  17  that does not have the positions of the connectors thereof reversed, and the heat sink  16  having the first flank thereof abutted on the heat radiation surface of the first power amplification unit  10  and having the second flank thereof abutted on the heat radiation surface of the second power amplification unit  17 . The transmitter  2  using the power amplification device  1  includes the multiple power amplification devices  1 , the distributor  22  directly coupled to the input connectors  151  and  152  of the multiple power amplification devices  1 , and the synthesizer  21  directly coupled to the output connectors  141  and  142  of the multiple power amplification devices  1 . 
     The connection wiring among the power amplification device  1 , distributor  22 , and synthesizer  21  can be simplified, and downsizing and reduction in a cost can be achieved. In addition, since a connecting part need not be used, a loss caused by radiofrequency amplification can be decreased and performance can be improved. 
     The present invention is not limited to the foregoing embodiment. Any of the components of the present invention can be modified without a departure from the gist of the invention. The components disclosed in the embodiment may be appropriately combined in order to constitute various inventions. For example, some of the components included in the embodiment may be excluded. Further, the components of different embodiments may be appropriately combined. 
     Although exemplary embodiments of the present invention have been shown and described, it will be apparent to those having ordinary skill in the art that a number of changes, modifications, or alterations to the invention as described herein may be made, none of which depart from the spirit of the present invention. All such changes, modifications, and alterations should therefore be seen as within the scope of the present invention.