Abstract:
A transformer hybrid is disclosed. The transformer hybrid comprises a substrate, a first conductor, a second conductor, a first coil, and a second coil. The first conductor includes a first elongate portion having a first side and a second side. The second conductor includes a second elongate portion having a third side and a fourth side, and the orientation of the second conductor intersects with that of the first conductor. The first coil is located near the first side and the third side. The second coil is located near the first side and the fourth side. When the direction of the loading current in the first coil is the same with that in the second coil, the first conductor has an inductive electromotive force. When the direction of the loading current in the first coil is different from that in the second coil, the second conductor has another inductive electromotive force. When phase difference exists between the loading currents, the two loading currents can be resolved to common mode and differential mode, so the inductive electromotive forces can be produced on the both conductors.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
       [0001]    This application claims priority to Taiwan Patent Application No. 102128174, filed on Aug. 6, 2013, the disclosure of which is hereby incorporated by reference in its entirety. 
       BACKGROUND 
       [0002]    1. Field of the Disclosure 
         [0003]    The present disclosure relates to a transformer hybrid, and more particularly, to a transformer hybrid with multiple input terminals. 
         [0004]    2. Description of the Related Art 
         [0005]    As the communication technology such as mobile phone, internet and digital TV become more popular and growth rapidly, the need of high quality and low cost CMOS power amplifier is increasing. However, one of the main problems of the current CMOS process is the low breakdown voltage and the high substrate loss of the silicon, therefore, the approach of power combination through the transformer or hybrid is proposed in order to reduce the area of the transistors as well as increase the output power and efficiency. 
         [0006]    However, traditional transformer combiners would produce large peak voltage when power cells are operated with phase difference. And traditional hybrid that implemented by transmission lines or lots of passive components is too large for chip design. 
         [0007]    Therefore, the transformer hybrid is very suitable to the mobile power amplifiers that requires high linearity and high output power level. 
       SUMMARY 
       [0008]    The present disclosure describes a transformer hybrid with small volume. 
         [0009]    In an embodiment, the transformer hybrid comprises a substrate, a first conductor, a second conductor, a first coil, and a second coil. The first conductor is disposed on the substrate, and has a first elongated portion comprising a first side and a second side. The second conductor is disposed on the substrate and adjacent to the first side, and has a second elongated portion comprising a third side and fourth side. An orientation of the second elongated portion crosses an orientation of the first elongated portion. The first coil is disposed on the substrate and adjacent to the first side and the third side, and has a first positive input terminal and a first negative input terminal facing with each other to form a first opening and configured to receive differential signals. The second coil is disposed on the substrate and adjacent to the first side and the fourth side, and has a second positive input terminal and a second negative input end facing with each other to form a second opening and configured to receive the different signals. When loading currents of the first coil and the second coil are in a same direction, the first conductor generates a first induction electromotive force, and when loading currents of the first coil and the second coil are in opposite directions, the second conductor generates a second induction electromotive force. 
         [0010]    In an embodiment, the transformer hybrid comprises a substrate, a circular conductor, a 8-shape conductor, a first coil, and a second coil. The circular conductor is disposed on the substrate, and has a first output terminal and a second output terminal facing with each other to form a first opening. The 8-shape conductor is disposed on the substrate and surrounded with the circular conductor, and has a first circular portion, a second circular portion, a first cross portion, a third output terminal and a fourth output terminal. The first cross portion is connected between the first circular portion and the second circular portion. The third output terminal and the fourth output terminal faces with each other to form a second opening. The first coil is disposed on the substrate and surrounded with the first circular portion, and has a first positive input terminal and a first negative input terminal facing with each other to form a third opening and configured to receive differential signals. The second coil is disposed on the substrate and surrounded with the second circular portion, and has a second positive input terminal and a second negative input terminal facing with each other to form a fourth opening and configured to receive the differential signals. When loading currents of the first coil and the second coil are in a same direction, the circular conductor generates a first induction electromotive force, and when loading currents of the first coil and the second coil are in opposite directions, the 8-shape conductor generates a second induction electromotive force. 
         [0011]    Overall, the present disclosure describes transformer hybrids with two coils for dual input. Each of the transformer hybrids has small volumes, anti-interference ability and high power capacity. Further, when the transformer hybrid is applied for the power amplifier, which has the advantage of high impedance transformation coefficient. 
         [0012]    The foregoing is a summary and shall not be construed to limit the scope of the claims. The operations and devices disclosed herein may be implemented in a number of ways, and such changes and modifications may be made without departing from this disclosure and its broader aspects. Other aspects, inventive features, and advantages, as defined solely by the claims, are described in the non-limiting detailed description set forth below. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1A  depicts a schematic diagram illustrating a transformer hybrid, in accordance with a first embodiment of the present disclosure. 
           [0014]      FIG. 1B  depicts a schematic diagram illustrating a transformer hybrid, in accordance with a second embodiment of the present disclosure. 
           [0015]      FIG. 1C  depicts a schematic diagram illustrating a transformer hybrid, in accordance with a third embodiment of the present disclosure. 
           [0016]      FIG. 1D  depicts a schematic diagram illustrating a transformer hybrid, in accordance with a fourth embodiment of the present disclosure. 
           [0017]      FIG. 1E  depicts a schematic diagram illustrating a transformer hybrid, in accordance with a fifth embodiment of the present disclosure. 
           [0018]      FIG. 2  depicts a schematic diagram illustrating a transformer hybrid, in accordance with a fourth embodiment of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0019]    For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features. One of ordinary skill in the art will understand other varieties for implementing example embodiments, including those described herein. The drawings are not limited to specific scale and similar reference numbers are used for representing similar elements. As used in the disclosure and the appended claims, the terms “example embodiment,” “exemplary embodiment,” and “present embodiment” do not necessarily refer to a single embodiment, although it may, and various example embodiments may be readily combined and interchanged, without departing from the scope or spirit of the present disclosure. Furthermore, the terminology as used herein is for the purpose of describing example embodiments only and is not intended to be a limitation of the disclosure. In this respect, as used herein, the term “in” may include “in” and “on”, and the terms “a”, “an” and “the” may include singular and plural references. Furthermore, as used herein, the term “by” may also mean “from”, depending on the context. Furthermore, as used herein, the term “if” may also mean “when” or “upon”, depending on the context. Furthermore, as used herein, the words “and/or” may refer to and encompass any and all possible combinations of one or more of the associated listed items. 
         [0020]      FIG. 1A  depicts a schematic diagram illustrating a transformer hybrid, in accordance with a first embodiment of the present disclosure. The transformer hybrid  1 A may comprise a substrate (not shown), a first conductor  14   a,  a second conductor  16   a,  a first coil  12   a,  and a second coil  12   b.  The first conductor  14   a,  the second conductor  16   a,  the first coil  12   a,  and the second coil  12   b  are formed in the same layer or different layers on the substrate by using the semiconductor process. In other words, the first conductor  14   a,  the second conductor  16   a,  the first coil  12   a,  and the second coil  12   b  may have different level heights on the substrate. In an embodiment, the substrate may be a ceramic substrate, a silicon substrate or a printed circuit board. In an alternative embodiment, the first conductor  14   a,  the second conductor  16   a,  the first coil  12   a,  and the second coil  12   b  may be suspended on the substrate by the RFMEMS transformer fabrication process. 
         [0021]    The first coil  12   a  and the second coil  12   b  may act as first and second primary loops of the transformer hybrid  1 A, respectively. The first conductor  14   a  and the second conductor  16   a  may act as first and second secondary loops of the transformer hybrids  1 A. Each of the first and second secondary loops  14   a,    16   a  may be induced by the first and second primary loops  12   a,    12   b  to generate induction electromotive force via proper arrangement of positions and distances of them. 
         [0022]    The first conductor  14   a  may comprise a first elongated portion  140 . The first elongated portion  140  may have a first output terminal  141 , a second output terminal  143 , a first side s 1 , and a second side s 2 . The second conductor  16   a  may comprise a second elongated portion  160 . The second elongated portion  160  may have a third output terminal  161 , a fourth output terminal  163 , a third side s 3 , and a fourth side s 4 . The second elongated portion  160  may be adjacent to the first side s 1 . An orientation of the second elongated portion  160  crosses an orientation of the first elongated portion  140 . That is, the second elongated portion  160  has a predetermined angle with respect to the first elongated portion  140 , for example, greater or smaller than 90°. The second elongated portion  160  may be adjacent to the first side s 1 . In an alternative embodiment, the second elongated portion  160  may be adjacent to the second side s 2  and have a predetermined angle with respect to the first elongated portion  140 . 
         [0023]    In an embodiment, the first coil  12   a  is adjacent to or between the first side s 1  and the third side s 3 . The first coil  12   a  may comprise a first positive input terminal  121  and a first negative input terminal  123 . The first positive input terminal  121  and the first negative input terminal  123  are spaced apart and opposite with each other or face with each other to form a first opening  125 . The first positive input terminal  121  and the first negative input terminal  123  are configured to receive differential signals in+, in−, so as to induce an alternative current on the first coil  12   a.  Similarly, the second coil  12   b  is adjacent to or between the first side s 1  and fourth side s 4 . The second coil  12   b  may comprise a second positive input terminal  122  and a second negative input terminal  124  spaced apart and opposite with each other or face with each other to form a second opening  126 . The second positive input terminal  122  and the second negative input terminal  124  are configured to receive the differential signals in+, in−, so as to induce an alternative current on the second coil  12   b.  The polarities of the differential signals in+, in− are not limited to the ones shown in  FIG. 1A . The positions of the first opening  125  and second opening  126  are not limited to the ones shown in  FIG. 1A . The first coil  12   a  and the second coil  12   b  may be identical. The number of the coils is not limited to the ones shown in  FIG. 1A , and at least one coil adjacent to the first and second conductor  14   a,    16   b  may implement the transformer hybrid. Each of the coils  12   a,    12   b  are not limited to the single turn winding structure as shown in  FIG. 1A , it also may be multiple turns such as Nturns, in which N is an integer. 
         [0024]    Each of the shape of the first coil  12   a  and the second coil  12   b  may circle loop, square loop, rectangular loop, or polygon loop with one opening. At least one side of the first coil  12   a  and the second coil  12   b  should be adjacent to the first and second conductors  14   a,    16   a.  The directions of the loading currents of the first coil  12   a  and the second coil  12   b  may be exchanged by controlling the polarities of the differential signals in+, in− of the input terminals  121 - 124 . For example, when the input terminal  121  receives a positive input signal in+, the direction of the loading current on the first coil  12   a  is clockwise. When the input terminal  121  receive a negative input signal in−, the direction of the loading current on the first coil  12   a  is counterclockwise. When the input terminal  122  receives a positive input signal in+, the direction of the loading current on the second coil  12   b  is counterclockwise. When the input terminal  122  receive a negative input signal in−, the direction of the loading current on the second coil  12   b  is clockwise. 
         [0025]    When the loading currents of the first coil  12   a  and the second coil  12   b  are in a same direction, such as in clockwise, the first conductor  14   a  generates a first induction electromotive force. More specifically, the voltage level of the output voltage out 2  of the second output terminal  143  is greater than that of the output voltage out 1  of the first output terminal  141 . At the same time, there is no induction electromotive force generated by the second conductor  16   a.    
         [0026]    When the loading currents of the first coil  12   a  and the second coil  12   b  are in opposite directions, such as the loading current of the first coil  12   a  is in clockwise, and the loading current of the second coil  12   b  is in counter clockwise, the second conductor  16   a  generates a second induction electromotive force. More specifically, the voltage level of the output voltage out 1 ′ of the third output terminal  161  is greater than that of the output voltage out 2 ′ of the fourth output terminal  163 . At the same time, there is no induction electromotive force generated by the first conductor  14   a.  In an embodiment, each of the first conductor  14   a  and the second conductor  16   a  may have a single terminal output or dual terminal outputs, as needed. 
         [0027]      FIG. 1B  depicts a schematic diagram illustrating a transformer hybrid, in accordance with a second embodiment of the present disclosure. The transformer hybrid  1 B of the second embodiment is similar to the transformer hybrid A 1  of the first embodiment. The transformer hybrid  1 B comprises a substrate (not shown), a first conductor  14   a,  a second conductor  16   b,  a first coil  12   a,  and a second coil  12   b.  The arrangement of the coils  12   a,    12   b  with respective to the conductors  14   a,    16   b  is the same as that of the first embodiment. The difference between the transformer hybrid  1 B and the transformer hybrid  1 A is that the second conductor  16   b  of the transformer hybrid  1 B further comprises a third elongated portion  162  and a cross portion c 1  disposed on the substrate. The third elongated portion  162  comprises a fifth side s 5  and sixth side s 6 . The cross portion c 1  is connected between the second elongated portion  160  and the third elongated portion  162  and overlaps the first conductor  14   a.  The third elongated portion  162  is adjacent to the second side s 2 . The cross portion c 1  of the second conductor  16   b  and the first elongated portion  140  have different level heights on the substrate, that is the cross portion c 1  does not electrically connected to the first elongate portion  140 . Extension directions of the third elongated portion  162  and the second elongated portion  160  are in a same direction. 
         [0028]    Further, the transformer hybrid  1 B may comprise a third coil  12   c,  and a fourth coil  12   d  disposed on the substrate. Each of the third coil  12   c  and the fourth coil  12   d  has an opening and is identical with the first coil  12   a.  The third coil  12   c  is adjacent to or between the second side s 2  and the fifth side s 5 . The fourth coil  12   d  is adjacent to or between the second side s 2  and the sixth side s 6 . Each of the third coil  12   c  and the fourth coil  12   d  has at least one turn winding. 
         [0029]    When the loading currents of the first coil  12   a  and the second coil  12   b  are in a first direction, and the loading currents of the third coil  12   c  and the fourth coil  12   d  are in a second direction opposite to the first direction, the first conductor  14   a  generates a third induction electromotive force. At the same time, there is no induction electromotive force generated by the second conductor  16   b.    
         [0030]    When the loading currents of the first coil  12   a  and the third coil  12   c  are in a third direction, and the loading currents of the second coil  12   b  and the fourth coil  12   d  are in a fourth direction opposite to the third direction, the second conductor  16   b  generates a fourth induction electromotive force. At the same time, there is no induction electromotive force generated by the first conductor  14   a.    
         [0031]      FIG. 1C  depicts a schematic diagram illustrating a transformer hybrid, in accordance with a third embodiment of the present disclosure. The transformer hybrid  1 C of the third embodiment is similar to the transformer hybrid A 1  of the first embodiment. 
         [0032]    The transformer hybrid  1 C comprises a substrate (not shown), a first conductor  14   c,  a second conductor  16   a,  a first coil  12   a,  and a second coil  12   b.  The arrangement of the coils  12   a,    12   b  with respective to the conductor  16   a  is the same as that of the first embodiment. The difference between the transformer hybrid  1 C and the transformer hybrid  1 A is that the first conductor  14   c  of the transformer hybrid  1 C further comprises a fourth elongated portion  142  and a fifth elongated portion  144 . The first elongated portion  140  has a first end  145  and a second end  147 . The first end  145  is connected to the fourth elongated portion  142 , and the second end  147  is connected to the fifth elongated portion  144 . The first elongated portion  140 , the fourth elongated portion  142  and the fifth elongated portion  144  form a fifth coil(i.e. the first conductor  14   c ) with a fifth opening  149 . 
         [0033]    The fifth coil  14   c  surrounds the second conductor  16   a,  the first coil  12   a  and the second coil  12   b.    
         [0034]    The fifth coil  14   c  further comprises a cross portion (not shown) overlapping the second conductor  16   a,  the first coil  12   a,  or the second coil  12   b.  The cross portion and the second conductor  16   a,  the first coil  12   a,  or the second coil  12   b  have different level heights on the substrate. 
         [0035]    When the loading currents of the first coil  12   a  and the second coil  12   b  are in a fifth direction, the first conductor  14   c  generates a fifth induction electromotive force. At the same time, there is no induction electromotive force generated by the second conductor  16   a.    
         [0036]    When the loading currents of the first coil  12   a  and the second coil  12   b  are in opposite directions, the second conductor  16   a  generates a sixth induction electromotive force. At the same time, there is no induction electromotive force generated by the first conductor  14   c.    
         [0037]    Alternatively, the transformer hybrid, in accordance with the third embodiment of the present disclosure can make a little change. As shown in  FIG. 1D , the second conductor  16   a  can stretch in the horizontal direction from both ends. That is, the second conductor  16   a  consisted three portions of a vertical part  161 , and a first horizontal part  162  and a second horizontal part  163 . Those two horizontal parts  162 ,  163  are parallel located between the coils  12   a,    12   b  and second output terminal  143 , first output terminal  143 , respectively. 
         [0038]    Alternatively, the transformer hybrid, in accordance with the third embodiment of the present disclosure can make a little more change. As shown in  FIG. 1E , the second conductor  16   a  can stretch further in the vertical direction from both ends. That is, the second conductor  16   a  consisted five portions of a first vertical parts  161 , a second vertical parts  164 , a third vertical parts  165 , a first horizontal part  162  and a second horizontal part  163 . Those two horizontal parts  162 ,  163  are parallel located between the coils  12   a,    12   b  and second output terminal  143 , first output terminal  143 , respectively, while those two vertical parts  165 ,  164  are parallel located between the coils  12   a,    12   b  and fourth elongated portion  142 , fifth elongated portion  144 , respectively. 
         [0039]      FIG. 2  depicts a schematic diagram illustrating a transformer hybrid, in accordance with a fourth embodiment of the present disclosure. The transformer hybrid  2  comprises a substrate (not shown), a circular conductor  24 , a 8-shape conductor  26 , a first coil  22   a,  and a second coil  22   b.  The circular conductor  24 , the 8-shape conductor  26 , the first coil  22   a,  and the second coil  22   b  are formed in the same layer or different layers on the substrate by using the semiconductor process. In other words, the circular conductor  24 , the 8-shape conductor  26 , the first coil  22   a,  and the second coil  22   b  may have different level heights on the substrate. 
         [0040]    In an embodiment, the circular conductor  24  comprises a first output terminal  241  and a second output terminal  243 . The first output terminal  241  and the second output terminal  243  are spaced apart and opposite with each other or face with each other to form a first opening  245 . The 8-shape conductor  26  is disposed on the substrate and surrounded with the circular conductor  24 . The 8-shape conductor  26  comprises a first circular portion  26   a,  a second circular portion  26   b,  a first cross portion c 2 , a third output terminal  261  and a fourth output terminal  263 . The first cross portion c 2  is connected between the first circular portion  26   a  and the second circular portion  26   b.  The third output terminal  261  and the fourth output terminal  263  face with each other to form a second opening  265 . The second opening  265  may be located on the first circular portion  26   a  or the second circular portion  26   b.  The first cross portion c 2  of 8-shape conductor  26  may have two different level heights on the substrate. 
         [0041]    The first coil  22   a  may be surrounded with one of the first circular portion  26   a  and the second circular portion  26   b,  and the second coil  22   b  may be surrounded with another one of the first circular portion  26   a  and the second circular portion  26   b.  The first coil  22   a  comprises a first positive input terminal  221  and a first negative input terminal  223  spaced apart and opposite with each other or face with each other to form a third opening  225 . The first positive input terminal  221  and the first negative input terminal  223  are configured to receive the differential signals in+, in−, so as to induce an alternative current on the circular conductor  24  or the 8-shape conductor  26 . 
         [0042]    Similarly, the second coil  22   b  comprises a second positive input terminal  222  and a second negative input terminal  224  spaced apart and opposite with each other or face with each other to form a fourth opening  226 . The second positive input terminal  222  and the second negative input terminal  224  are configured to receive the differential signals in+, in−, so as to induce an alternative current on the circular conductor  24  or the 8-shape conductor  26 . 
         [0043]    In an embodiment, the circular conductor  24  further comprises a second cross portion (not shown) overlapping the 8-shape conductor  26 . The second cross portion and the 8-shape conductor  26  have different level heights on the substrate. In an embodiment, the circular conductor  24  further comprises a third cross portion (not shown) overlapping the first coil  22   a  or the second coil  22   b.  The third cross portion and the first coil  22   a  or the second coil  22   b  have different level heights on the substrate. In an embodiment, the 8-shape conductor  26  further comprises a fourth cross portion (not shown) overlapping the first coil  22   a  or the second coil  22   b.  The fourth cross portion and the first coil  22   a  or the second coil  22   b  have different level heights on the substrate. 
         [0044]    In an embodiment, each of the first coil  22   a  and the second coil  22   b  may be in circle loop, square loop, rectangular loop, or polygon loop shape. In an embodiment, each of the first circular portion  26   a  and the second circular portion  26   b  may be in circle loop, square loop, rectangular loop, or polygon loop shape. Each of he coils  22   a,    22   b,  the circular conductor  24 , and the circular portions  26   a,    26   b  are not limited to the single turn winding structure as shown in  FIG. 2 , it also may be multiple turns such as N turns, in which N is an integer. 
         [0045]    The directions of the loading currents of the coils  22   a,    22   b  may be exchanged by controlling the polarities of the differential signals in+, in− of the input terminals  221 - 224  of the coils  22   a,    22   b.  For example, when the loading currents of the first coil  22   a  and the second coil  22   b  are in a same direction, the circular conductor  24  generates a first induction electromotive force. At the same time, there is no induction electromotive force generated by the 8-shape conductor  26 . When the loading currents of the first coil  22   a  and the second coil  22   b  are in opposite directions, the 8-shape conductor  26  generates a second induction electromotive force. At the same time, there is no induction electromotive force generated by the circular conductor  24 . 
         [0046]    Accordingly, each transformer hybrid of above-mentioned embodiments has at least two primary windings and two secondary windings. At least one of the two secondary windings could generate an induction electromotive force by controlling the polarities of the differential signals in+, in- of the input terminals of the two primary windings. Moreover, the structures of the above-mentioned transformer hybrids are simple, which is favorable for being designed and implemented in the field of system on chip applications. 
         [0047]    Realizations in accordance with the present disclosure have been described in the context of particular embodiments. These embodiments are meant to be illustrative and not limiting. Many variations, modifications, additions, and improvements are possible. Accordingly, plural instances may be provided for components described herein as a single instance. Structures and functionality presented as discrete components in the exemplary configurations may be implemented as a combined structure or component. These and other variations, modifications, additions, and improvements may fall within the scope of the invention as defined in the claims that follow. 
         [0048]    While various embodiments in accordance with the principles disclosed herein have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of this disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with any claims and their equivalents issuing from this disclosure. Furthermore, the above advantages and features are provided in described embodiments, but shall not limit the application of such issued claims to processes and structures accomplishing any or all of the above advantages. 
         [0049]    Additionally, the section headings herein are provided for consistency with the suggestions under 37 CFR 1.77 or otherwise to provide organizational cues. These headings shall not limit or characterize the embodiment(s) set out in any claims that may issue from this disclosure. Specifically and by way of example, although the headings refer to a “Field of the Disclosure,” the claims should not be limited by the language chosen under this heading to describe the so-called field. Further, a description of a technology in the “Background” is not to be construed as an admission that certain technology is prior art to any embodiment(s) in this disclosure. Neither is the “Summary” to be considered as a characterization of the embodiment(s) set forth in issued claims. Furthermore, any reference in this disclosure to “invention” in the singular should not be used to argue that there is only a single point of novelty in this disclosure. Multiple embodiments may be set forth according to the limitations of the multiple claims issuing from this disclosure, and such claims accordingly define the embodiment(s), and their equivalents, that are protected thereby. In all instances, the scope of such claims shall be considered on their own merits in light of this disclosure, but should not be constrained by the headings set forth herein.