Synthetic balun and differential amplifier

Abstract

A synthesized balun and differential amplifier are provided to suppress the reduction in conversion efficiency from differential signals to single-phase signals. The synthesized balun includes: a first input-side conductive member wound around a first axis on a first surface intersecting the first axis, and having a first portion located between the first axis and a second axis substantially parallel to the first axis, allowing a first input current to flow; a second input-side conductive member wound around the second axis on the first surface, and having a second portion located between the second axis and the first portion, allowing a second input current to flow in the same direction as the first input current; a first output-side conductive member wound around the first axis on a second surface opposite to the first surface, and having a third portion opposite to the first portion; and a second output-side conductive member wound around the second axis on a second surface, and having a fourth portion opposite to the second portion.

Description

Technical Field

[0001] The present invention relates to a synthetic balun and a differential amplification device. Background Art

[0002] There is a power amplification device that synthesizes the outputs of multiple amplifier pairs using a transformer (for example, refer to Patent Document 1). In addition, in a Doherty amplifier, there is a technique in which a peak amplifier and a carrier amplifier are each composed of a differential amplifier pair, and the outputs of the amplifier pair on the peak amplifier side and the outputs of the amplifier pair on the carrier amplifier side are synthesized through a transformer (for example, refer to Non-Patent Documents 1 and 2).

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2011-66599

[0006] Non-Patent Documents

[0007] Non-Patent Document 1: Chenxi Zhao, et al., "Analysis and Design of CMOS Doherty Power Amplifier Based on Voltage Combining Method", IEEE Access, United States, IEEE, March 16, 2017, Volume 5, p. 5001-5012

[0008] Non-Patent Document 2: Chenxi Zhao, et al., "Analysis and Design of CMOS Doherty Power Amplifier Using Voltage Combining Method", [online], April 14-18, 2013, 2013 IEEE International Wireless Symposium (IWS), [retrieved on November 19, 2020], Internet <URL: https: / / ieeexplore.ieee.org / abstract / document / <6616725> Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] In the power amplifier device described in Patent Document 1 and the Dougherty amplifier described in Non-Patent Documents 1 and 2, the structure is as follows: two inductors are provided on the input side of the transformer, and two signals with opposite phases and the same amplitude are supplied to the two ends of these inductors respectively.

[0011] In these two inductors, for example, the direction of the magnetic field generated inside one inductor is sometimes opposite to the direction of the magnetic field generated inside the other inductor. In such cases, the magnetic fields sometimes cancel each other out, reducing the conversion efficiency from differential signal to single-phase signal.

[0012] The present invention was made in view of the following circumstances, and its object is to provide a synthetic balun and differential amplifier that suppresses the reduction in conversion efficiency from differential signals to single-phase signals.

[0013] Methods for solving problems

[0014] A synthetic balun inductively coupled converter according to one aspect of the present invention comprises: a first input-side conductive member wound around the first axis on a first surface intersecting the first axis and having a first portion located between the first axis and a second axis substantially parallel to the first axis, and allowing a first input current to flow; a second input-side conductive member wound around the second axis on the first surface and having a second portion located between the second axis and the first portion, and allowing a second input current to flow in the same direction as the first input current; a first output-side conductive member wound around the first axis on a second surface opposite to the first surface and having a third portion opposite to the first portion; a second output-side conductive member wound around the second axis on the second surface and having a fourth portion opposite to the second portion; and a first output terminal that outputs a current or voltage generated in the first output-side conductive member and the second output-side conductive member based on the first input current and the second input current.

[0015] Invention Effects

[0016] According to the present invention, a synthetic balun and differential amplifier device can be provided to suppress the reduction in conversion efficiency from differential signal to single-phase signal. Attached Figure Description

[0017] Figure 1 This is the circuit diagram of differential amplifier circuit 11.

[0018] Figure 2 This is a top view of the current synthesis balancing / unbalancing converter 101.

[0019] Figure 3 This is a diagram showing an example of the layout of the input section 40 in the current synthesis balancing / unbalancing converter 101.

[0020] Figure 4 This is a diagram showing an example of the layout of the upper inductor group 50a in the current synthesis balancing-unbalancing converter 101.

[0021] Figure 5 This is a diagram illustrating an example of the layout of the lower inductor group 50b in the current synthesis balancing / unbalancing converter 101.

[0022] Figure 6 This is the circuit diagram used in the simulation of the current synthesis balancing / unbalancing converter 101.

[0023] Figure 7 This is a diagram showing an example of the frequency variation of an inductor observed from various signal sources.

[0024] Figure 8 This is a diagram illustrating an example of the frequency variation of the coupling coefficients of each transformer in the current synthesis balancing / unbalancing converter 101.

[0025] Figure 9 This is the circuit diagram of differential amplifier circuit 12.

[0026] Figure 10 This is a diagram showing an example of the layout of input section 40 and input section 140.

[0027] Figure 11 This is a diagram showing an example of the layout of the upper inductor group 50a and the upper inductor group 150a.

[0028] Figure 12 This is a diagram showing an example of the layout of the lower inductor group 50b and the lower inductor group 150b.

[0029] Figure 13 This is a diagram showing an example of the layout of the input section 240 in the current synthesis balancing / unbalancing converter 101.

[0030] Figure 14 This is a diagram showing an example of the layout of a differential amplifier device for reference.

[0031] Figure 15 This is a diagram illustrating an example of the layout of the upper inductor group 90a in a current-synthesizing balancing / unbalancing converter of the reference example.

[0032] Figure 16 This is a diagram showing an example of the frequency variation of an inductor in a reference example as observed from various signal sources.

[0033] Figure 17This is a diagram illustrating an example of the frequency variation of the coupling coefficients of the transformers in a current-synthesizing balancing-unbalancing converter of a reference example.

[0034] Figure 18 This is the circuit diagram of differential amplifier circuit 13.

[0035] Figure 19 This is a diagram showing an example of the layout of the upper inductor group 350a in the voltage synthesis balancing / unbalancing converter 301.

[0036] Figure 20 This is a diagram illustrating an example of the layout of the lower inductor group 350b in a voltage synthesis balancing / unbalancing converter 301.

[0037] Figure 21 This is the circuit diagram of differential amplifier circuit 14.

[0038] Explanation of reference numerals in the attached figures

[0039] 11, 12... Differential amplifier circuit;

[0040] 21...Input terminals;

[0041] 22... Output terminals;

[0042] 31a, 131a... First amplifier;

[0043] 31b, 131b... Second amplifier;

[0044] 31C, 131C... third amplifier;

[0045] 31d, 131d... Fourth amplifier;

[0046] 31e... Fifth Amplifier;

[0047] 31f...Sixth Amplifier;

[0048] 31g...Seventh Amplifier;

[0049] 31h...Eighth Amplifier;

[0050] 40... Input section;

[0051] 41...First input-side inductor;

[0052] 41a...First end;

[0053] 41b...Second end;

[0054] 41h... Part 1;

[0055] 42...Second input-side inductor;

[0056] 42a...First end;

[0057] 42b...second end;

[0058] 42h... Part Two;

[0059] 47...Inductors;

[0060] 50... Output section;

[0061] 50a... Upper inductor group;

[0062] 50b...lower side inductor group;

[0063] 51...First output-side inductor;

[0064] 51d... Part Three;

[0065] 52...Second output-side inductor;

[0066] 52e...Part Four;

[0067] 53...Third output-side inductor;

[0068] 53d...Part Five;

[0069] 54... Fourth output-side inductor;

[0070] 54e... Part Six;

[0071] 55a...First output terminal;

[0072] 57a, 57c, 57d... connect conductive components;

[0073] 61...First axis;

[0074] 62...Second axis;

[0075] 63... plane of symmetry;

[0076] 66...First page;

[0077] 67...Second page;

[0078] 68... Third page;

[0079] 81, 82... Output-side inductors;

[0080] 101... Current-synthesizing balancing / unbalancing converter;

[0081] 140... Input section;

[0082] 140a, 140b... Input-side inductor group;

[0083] 150... Output section;

[0084] 150a... Upper inductor group;

[0085] 150b...lower side inductor group;

[0086] 240... Input section;

[0087] 301... Voltage synthesizing balancing / unbalancing converter;

[0088] 350... Output section;

[0089] 350a... Upper inductor group;

[0090] 350b...lower side inductor group;

[0091] 351...First output-side inductor;

[0092] 351d... Part Three;

[0093] 352...Second output-side inductor;

[0094] 352e...Part Four;

[0095] 353...Third output-side inductor;

[0096] 353d... Part Five;

[0097] 354... Fourth output-side inductor;

[0098] 354e... Part Six;

[0099] 357a... connects conductive components;

[0100] 381, 382... Output-side inductors;

[0101] 401... Balanced / Unbalanced Converter;

[0102] 1101... Current synthesis balancing / unbalancing converter. Detailed Implementation

[0103] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the same reference numerals are used for the same elements, and repeated descriptions are omitted as much as possible.

[0104] [First Implementation Method]

[0105] The differential amplifier device of the first embodiment will be described.

[0106] Figure 1 This is the circuit diagram of differential amplifier circuit 11. (Example) Figure 1 As shown, the differential amplifier circuit 11 is a circuit provided in the differential amplifier device, including a first amplifier 31a, a second amplifier 31b, a third amplifier 31c, a fourth amplifier 31d, an inductor 47, and a current combining balancing / unbalancing converter 101. The current combining balancing / unbalancing converter 101 includes an input section 40 and an output section 50. The input section 40 includes a first input-side inductor 41 (a first input-side conductive member) and a second input-side inductor 42 (a second input-side conductive member). The output section 50 includes an output-side inductor 81 and an output-side inductor 82.

[0107] The differential amplifier circuit 11 amplifies the first and second differential signals respectively, and converts the amplified first and second differential signals into two single-ended signals (single-phase signals). Furthermore, the differential amplifier circuit 11 outputs an output signal RFout, which is a combination of these single-ended signals, from the output terminal 22. Here, each differential signal is, for example, a radio frequency signal.

[0108] In detail, the first differential signal includes a first signal RF1 and a second signal RF2 having a different phase from the first signal RF1. Specifically, the phase of the first signal RF1 is approximately 180° different from the phase of the second signal RF2. The first signal RF1 and the second signal RF2 are generated, for example, by a balun provided in the pre-stage of the differential amplifier circuit 11.

[0109] The second differential signal includes a third signal RF3 having approximately the same phase as the first signal RF1 and a fourth signal RF4 having approximately the same phase as the second signal RF2. As mentioned above, the phase of the first signal RF1 is approximately 180° different from the phase of the second signal RF2; therefore, the phase of the third signal RF3 is approximately 180° different from the phase of the fourth signal RF4. The third signal RF3 and the fourth signal RF4 are generated, for example, by a balun provided in the pre-stage of the differential amplifier circuit 11.

[0110] The first amplifier 31a, the second amplifier 31b, the third amplifier 31c, and the fourth amplifier 31d are constructed, for example, from bipolar transistors such as heterojunction bipolar transistors (HBTs). It should be noted that these amplifiers can also be constructed from field effect transistors (FETs).

[0111] The first amplifier 31a has an input terminal and an output terminal connected to the input terminal 21a. The first amplifier 31a amplifies the first signal RF1 supplied to the input terminal through the input terminal 21a and outputs the first amplified signal ARF1 from the output terminal.

[0112] The second amplifier 31b has an input terminal and an output terminal connected to the input terminal 21b. The second amplifier 31b amplifies the second signal RF2 supplied to the input terminal through the input terminal 21b and outputs the amplified second signal ARF2 from the output terminal.

[0113] The third amplifier 31c has an input terminal and an output terminal connected to the input terminal 21c. The third amplifier 31c amplifies the third signal RF3 supplied to the input terminal through the input terminal 21c and outputs the amplified third signal ARF3 from the output terminal.

[0114] The fourth amplifier 31d has an input terminal and an output terminal connected to the input terminal 21d. The fourth amplifier 31d amplifies the fourth signal RF4 supplied to the input terminal through the input terminal 21d and outputs the amplified fourth signal ARF4 from the output terminal.

[0115] In the current synthesizing balun 101, the first input-side inductor 41 in the input section 40 has a first terminal 41a connected to the output terminal of the first amplifier 31a, a second terminal 41b connected to the output terminal of the second amplifier 31b, and an intermediate tap 41c connected to the power supply voltage supply node N1 via the inductor 47. The first amplifier 31a and the second amplifier 31b perform amplification using the voltage received from the power supply voltage supply node N1 through the inductor 47 and the intermediate tap 41c.

[0116] The output-side inductor 81 in the output section 50 is primarily electromagnetically coupled to the first input-side inductor 41, and generates an output current based on the electromagnetic field generated by the first amplified signal ARF1 and the second amplified signal ARF2 supplied to the first input-side inductor 41. The output current will be described in detail later. In this embodiment, the output-side inductor 81 has a first terminal 81a connected to the output terminal 22 and a second terminal 81b grounded. It should be noted that the output-side inductor 81 is obtained by connecting two inductors in series, which will be described in detail later.

[0117] The second input-side inductor 42 in the input section 40 is the same inductor as the first input-side inductor 41. Specifically, the second input-side inductor 42 has a first terminal 42a connected to the output terminal of the third amplifier 31c, a second terminal 42b connected to the output terminal of the fourth amplifier 31d, and a center tap 42c connected to the power supply voltage supply node N1 via the inductor 47. The third amplifier 31c and the fourth amplifier 31d perform amplification using the voltage received from the power supply voltage supply node N1 through the inductor 47 and the center tap 42c.

[0118] The output-side inductor 82 in the output section 50 is primarily electromagnetically coupled to the second input-side inductor 42, and generates an output current based on the electromagnetic field generated by the third amplified signal ARF3 and the fourth amplified signal ARF4 supplied to the second input-side inductor 42. The output current will be described in detail later. In this embodiment, the output-side inductor 82 is the same inductor as the output-side inductor 81, having a first terminal 82a connected to the output terminal 22 and a second terminal 82b grounded. It should be noted that the output-side inductor 82 is formed by two inductors connected in series, which will be described in detail later.

[0119] [layout]

[0120] The layout of the differential amplifier circuit 11 will be described. It should be noted that the x-axis, y-axis, and z-axis are sometimes shown in the diagram. The x-axis, y-axis, and z-axis form a right-handed three-dimensional orthogonal coordinate system. Hereinafter, the direction of the arrow on the z-axis will sometimes be referred to as the z-axis + side, and the opposite direction will be referred to as the z-axis - side; the same applies to the other axes. It should also be noted that the z-axis + side and z-axis - side are sometimes referred to as the "upper side" and "lower side," respectively.

[0121] Figure 2 This is a top view of the current synthesis balanced / unbalanced converter 101 observed from the y-axis + side. Figure 3 This is a diagram showing an example of the layout of the input section 40 in the current synthesis balancing / unbalancing converter 101. Figure 4 This is a diagram showing an example of the layout of the upper inductor group 50a in the current synthesis balancing-unbalancing converter 101. Figure 5 This is a diagram illustrating an example of the layout of the lower inductor group 50b in the current synthesis balancing / unbalancing converter 101.

[0122] here, Figures 3-5 This is a top view of the input section 40, the upper inductor group 50a, or the lower inductor group 50b, viewed from the z-axis + side. It should be noted that... Figure 3 The diagram schematically shows a first amplifier 31a, a second amplifier 31b, a third amplifier 31c, a fourth amplifier 31d, and an inductor 47.

[0123] like Figures 2-5 As shown, the output section 50 includes an upper inductor group 50a and a lower inductor group 50b. The first axis 61 and the second axis 62 are both axes approximately parallel to the z-axis. The second axis 62 is located on the x-axis+ side of the first axis 61, spaced a fixed interval from it. The direction from the first axis 61 toward the second axis 62 (hereinafter sometimes referred to as the first direction) is approximately the same as the x-axis direction. It should be noted that the first axis 61 and the second axis 62 are hypothetical axes for a deeper understanding of the invention and are not actually implemented in the product.

[0124] Figure 2 The first surface 66, the second surface 67, and the third surface 68 shown are surfaces that intersect the first axis 61 and the second axis 62 approximately perpendicularly. The second surface 67 is opposite to the first surface 66 and is located above the first surface 66. The third surface 68 is opposite to the second surface 67 across the first surface 66 and is located below the first surface 66. The interval between the first surface 66 and the second surface 67 is, for example, approximately equal to the interval between the first surface 66 and the third surface 68.

[0125] Figure 2 and Figure 3 The input section 40 shown is located on the second layer along the first surface 66. Figure 2 and Figure 4 The upper inductor group 50a shown is disposed in the first layer along the second surface 67. Figure 2 and Figure 5 The lower inductor group 50b shown is disposed on the third layer along the third surface 68.

[0126] In this embodiment, the first amplifier 31a, the second amplifier 31b, the third amplifier 31c, and the fourth amplifier 31d are arranged on the second layer, for example, in the order of second amplifier 31b, first amplifier 31a, third amplifier 31c, and fourth amplifier 31d, facing the x-axis + side (see reference). Figure 3 ).

[0127] Figure 3 The first input-side inductor 41 in the input section 40 shown is wound around the first shaft 61. In this embodiment, the first input-side inductor 41 is wound around the first shaft 61 for approximately half a turn. Specifically, the first input-side inductor 41 is disposed on the y-axis side of the second amplifier 31b and the first amplifier 31a, and has a positive-side extension 41d, a negative-side extension 41e, a connecting portion 41f, and a protrusion 41g.

[0128] In detail, the positive side extension 41d is located on the y-axis side of the first amplifier 31a and between the first axis 61 and the second axis 62. The positive side extension 41d has a shape that extends from the first end 41a connected to the output terminal of the first amplifier 31a toward the y-axis side.

[0129] The negative-side extension 41e is located on the y-axis side of the second amplifier 31b and is located on the opposite side of the positive-side extension 41d with reference to the first axis 61. The negative-side extension 41e has a shape that extends from the second end 41b connected to the output terminal of the second amplifier 31b toward the y-axis side.

[0130] The connecting portion 41f is located on the y-axis side of the first axis 61 and has a shape that extends substantially parallel to the x-axis direction. The connecting portion 41f connects the y-axis side end of the positive side extension 41d to the y-axis side end of the negative side extension 41e.

[0131] The protrusion 41g has a shape that protrudes from the midpoint of the two ends of the connecting portion 41f toward the y-axis side, and functions as a center tap 41c. The first input-side inductor 41 has a U-shaped opening in the direction from the y-axis side toward the y-axis+ side (hereinafter sometimes referred to as the second direction).

[0132] Figure 3 The second input-side inductor 42 shown is wound around the second shaft 62. In this embodiment, the second input-side inductor 42 is wound around the second shaft 62 approximately half a turn. Specifically, the second input-side inductor 42 is disposed on the y-axis side of the third amplifier 31c and the fourth amplifier 31d, and has a positive-side extension 42d, a negative-side extension 42e, a connecting portion 42f, and a protrusion 42g.

[0133] The second input-side inductor 42 has a shape that is approximately symmetrical to the first input-side inductor 41 about a symmetry plane 63. Here, the symmetry plane 63 is located between the first axis 61 and the second axis 62, and is a plane approximately parallel to the yz plane. That is, the second input-side inductor 42 is located on the x-axis+ side of the first input-side inductor 41, and has an overall U-shaped opening in the second direction. It should be noted that the symmetry plane 63 is an imaginary plane for ease of understanding the invention and is not actually provided.

[0134] In detail, the positive extension 42d is located on the y-axis side of the third amplifier 31c, and is located between the positive extension 41d in the first input-side inductor 41 and the second axis 62. The positive extension 42d has a shape that extends from the first end 42a connected to the output terminal of the third amplifier 31c toward the y-axis side.

[0135] The negative-side extension 42e is located on the y-axis side of the fourth amplifier 31d and on the opposite side of the positive-side extension 42d with reference to the second axis 62. The negative-side extension 42e has a shape that extends from the second end 42b connected to the output terminal of the fourth amplifier 31d toward the y-axis side.

[0136] The connecting portion 42f is located on the y-axis side of the second axis 62 and has a shape that extends approximately parallel to the x-axis direction. The connecting portion 42f connects the y-axis side end of the positive side extension 42d to the y-axis side end of the negative side extension 42e.

[0137] The protrusion 42g has a shape that protrudes from the midpoint of the two ends of the connecting part 42f toward the y-axis side, and functions as an intermediate tap 42c.

[0138] In the positive side extension 41d of the first input-side inductor 41, more specifically, in the first portion 41h located between the first shaft 61 and the second shaft 62 in the positive side extension 41d, a first input current i1 flows based on the first amplified signal ARF1 and the second amplified signal ARF2 supplied from the first amplifier 31a and the second amplifier 31b, respectively.

[0139] In the positive side extension 42d of the second input-side inductor 42, more specifically, in the second part 42h located between the first part 41h and the second shaft 62 in the positive side extension 42d, the second input current i2 flows based on the third amplification signal ARF3 and the fourth amplification signal ARF4 supplied from the third amplifier 31c and the fourth amplifier 31d, respectively.

[0140] The phase difference between the first amplified signal ARF1 and the second amplified signal ARF2 is approximately 180°, and similarly, the phase difference between the third amplified signal ARF3 and the fourth amplified signal ARF4 is approximately 180°. Furthermore, the phases of the first amplified signal ARF1 and the third amplified signal ARF3 are approximately the same. Therefore, the currents of the first amplified signal ARF1 and the third amplified signal ARF3 flow adjacent to each other, and since these signals are in phase, the direction of the second input current i2 is the same as the direction of the first input current i1.

[0141] Therefore, the direction of the magnetic field generated by the first input current i1 on the inner side 41i of the first input-side inductor 41 is opposite to the direction of the magnetic field generated by the second input current i2 on the inner side 42i of the second input-side inductor 42. Here, the inner side 41i of the first input-side inductor 41 is, for example, the area surrounded by the positive side extension 41d, the negative side extension 41e, and the connecting portion 41f. Similarly, the inner side 42i of the second input-side inductor 42 is, for example, the area surrounded by the positive side extension 42d, the negative side extension 42e, and the connecting portion 42f.

[0142] However, the direction of the magnetic field on the inner side 41i of the first input-side inductor 41 is opposite to the direction of the magnetic field on the outer side of the first input-side inductor 41. Similarly, the direction of the magnetic field on the inner side 42i of the second input-side inductor 42 is opposite to the direction of the magnetic field on the outer side of the second input-side inductor 42.

[0143] Here, the outer side 41j of the first input-side inductor 41 is, for example, the outer portion of the outline of the first input-side inductor 41 that forms a quadrilateral shape when viewed as a whole. That is, the inner side 42i of the second input-side inductor 42 is contained within the outer side 41j of the first input-side inductor 41.

[0144] The outer side 42j of the second input-side inductor 42 is, for example, the range along the outer periphery of the second input-side inductor 42, which forms a quadrilateral outline when viewed as a whole. That is, the inner side 41i of the first input-side inductor 41 is included in the outer side 42j of the second input-side inductor 42.

[0145] Therefore, for example, when the first input current i1 generates a magnetic field toward the z-axis + side on the inner side 41i of the first input-side inductor 41, a magnetic field toward the z-axis - side is generated on the outer side 41j of the first input-side inductor 41. At this time, the second input current i2 generates a magnetic field toward the z-axis - side on the inner side 42i of the second input-side inductor 42, and generates a magnetic field toward the z-axis + side on the outer side 42j of the second input-side inductor 42.

[0146] On the other hand, for example, when the first input current i1 generates a magnetic field toward the z-axis side on the inner side 41i of the first input-side inductor 41, a magnetic field toward the z-axis side is generated on the outer side 41j of the first input-side inductor 41. At this time, the second input current i2 generates a magnetic field toward the z-axis side on the inner side 42i of the second input-side inductor 42, and generates a magnetic field toward the z-axis side on the outer side 42j of the second input-side inductor 42.

[0147] That is, the direction of the magnetic field generated by the first input current i1 on the inner side 41i of the first input-side inductor 41 is the same as the direction of the magnetic field generated by the second input current i2 on the outer side 42j of the second input-side inductor 42. Furthermore, the direction of the magnetic field generated by the second input current i2 on the inner side 42i of the second input-side inductor 42 is the same as the direction of the magnetic field generated by the first input current i1 on the outer side 41j of the first input-side inductor 41.

[0148] That is, the magnetic field generated by the first input current i1 on the inner side 41i of the first input-side inductor 41 is enhanced by the magnetic field generated by the second input current i2 on the outer side 42j of the second input-side inductor 42 within the magnetic field on the inner side 41i of the first input-side inductor 41. Furthermore, the magnetic field generated by the second input current i2 on the inner side 42i of the second input-side inductor 42 is enhanced by the magnetic field generated by the first input current i1 on the outer side 41j of the first input-side inductor 41 within the magnetic field on the inner side 42i of the second input-side inductor 42. Therefore, the coupling coefficient in the current-synthesizing balun 101 can be increased, thus suppressing the reduction in conversion efficiency from differential signal to single-phase signal.

[0149] For the upper inductor group 50a (refer to) Figure 4 ) and lower inductor group 50b (refer to Figure 5 (This will be explained.)

[0150] The upper inductor group 50a includes a first output-side inductor 51 (first output-side conductive member), a second output-side inductor 52 (second output-side conductive member), a connecting portion 50aa, and a protrusion 50ab. The lower inductor group 50b includes a third output-side inductor 53 (third output-side conductive member) and a fourth output-side inductor 54 (fourth output-side conductive member).

[0151] The first output-side inductor 51 in the upper inductor group 50a is located on the z-axis+ side of the first input-side inductor 41 and is wound around the first shaft 61. Specifically, when viewed from above the upper inductor group 50a from the z-axis+ side, the first output-side inductor 51 has a first end 51a and a second end 51b disposed at a position overlapping the first shaft 61. In this top-view view, the first output-side inductor 51 is separated from the first shaft 61 from the second end 51b to the first end 51a and wound clockwise approximately 360°. This structure shortens the overall length of the first output-side inductor 51.

[0152] The second output-side inductor 52 is located on the z-axis+ side of the second input-side inductor 42. The second output-side inductor 52 has a shape that is approximately symmetrical to the first output-side inductor 51 about the symmetry plane 63. That is, the second output-side inductor 52 is located on the x-axis+ side of the first output-side inductor 51 and is wound around the second shaft 62 in a direction opposite to the winding direction of the first output-side inductor 51.

[0153] In detail, when viewed from the z-axis+ side of the upper inductor group 50a, the second output-side inductor 52 has a first end 52a and a second end 52b disposed at a position overlapping with the second axis 62. In this top-view view, the second output-side inductor 52 is separated from the second axis 62 from the second end 52b to the first end 52a and wound counterclockwise approximately 360°. This structure allows for a shorter overall length of the second output-side inductor 52.

[0154] The connecting portion 50aa has a shape that extends substantially parallel to the x-axis direction, connecting the first end 51a of the first output-side inductor 51 to the first end 52a of the second output-side inductor 52. The protrusion 50ab has a shape that protrudes from the midpoint between the two ends of the connecting portion 50aa toward the y-axis.

[0155] The first output-side inductor 51 has a third portion 51d opposite to the first portion 41h in the first input-side inductor 41. The third portion 51d is located between the first shaft 61 and the second shaft 62.

[0156] The second output-side inductor 52 has a fourth portion 52e opposite to the second portion 42h in the second input-side inductor 42. The fourth portion 52e is located between the third portion 51d and the second shaft 62.

[0157] A first output current i3 flows in the third section 51d based on the first input current i1. Specifically, through the change in the magnetic field generated primarily by the first input current i1 flowing in the first input-side inductor 41, an electric field is generated in the first output-side inductor 51 along the direction in which the first output-side inductor 51 is wound. The first output current i3 flows in the third section 51d through this generated electric field.

[0158] In the fourth section 52e, a second output current i4, based on the second input current i2, flows in the same direction as the first output current i3. Specifically, through the change in the magnetic field generated primarily by the second input current i2 flowing through the second input-side inductor 42, an electric field is generated in the second output-side inductor 52 in the direction in which the second output-side inductor 52 is wound. As described above, the direction of the magnetic field generated by the first input current i1 is opposite to the direction of the magnetic field generated by the second input current i2; therefore, in the fourth section 52e, the second output current i4 flows in the same direction as the first output current i3 through this electric field.

[0159] The third output-side inductor 53 and the fourth output-side inductor 54 in the lower inductor group 50b are wound in directions opposite to the winding direction of the first output-side inductor 51 and the second output-side inductor 52 in the upper inductor group 50a, respectively.

[0160] Specifically, the third output-side inductor 53 in the lower inductor group 50b is located on the z-axis side of the first input-side inductor 41, and is wound around the first shaft 61 in a direction opposite to the winding direction of the first output-side inductor 51. Specifically, when viewed from the z-axis+ side, the third output-side inductor 53 has a grounded first end 53a and a second end 53b located at a position overlapping the first shaft 61. In this top view, the third output-side inductor 53 is separated from the first shaft 61 from the second end 53b to the first end 53a and wound counterclockwise approximately 360°. The second end 53b is connected to the second end 51b of the first output-side inductor 51 via a via 56a (see reference). Figure 2 A via 56a is disposed along the first axis 61 and passes through the inner side 41i of the first input-side inductor 41.

[0161] The fourth output-side inductor 54 is located on the z-axis side of the second input-side inductor 42. The fourth output-side inductor 54 has a shape that is approximately symmetrical to the third output-side inductor 53 about the plane of symmetry 63. That is, the fourth output-side inductor 54 is located on the x-axis+ side of the third output-side inductor 53 and is wound around the second shaft 62 in a direction opposite to the winding direction of the third output-side inductor 53. In other words, the fourth output-side inductor 54 is wound around the second shaft 62 in a direction opposite to the winding direction of the second output-side inductor 52.

[0162] In detail, when viewed from the z-axis+ side of the lower inductor group 50b, the fourth output-side inductor 54 has a grounded first end 54a and a second end 54b disposed at a position overlapping with the second axis 62. In this top-view view, the fourth output-side inductor 54 is separated from the second axis 62 from the second end 54b to the first end 54a and wound clockwise approximately 360°. The second end 54b is connected to the second end 52b of the second output-side inductor 52 via a through-hole 56b (see reference). Figure 2 The via 56b is disposed along the second axis 62 and passes through the inner side 42i of the second input-side inductor 42.

[0163] The third output-side inductor 53 has a fifth portion 53d that is opposite to the third portion 51d of the first output-side inductor 51, separated from the first portion 41h of the first input-side inductor 41. The fifth portion 53d is located between the first shaft 61 and the second shaft 62.

[0164] The fourth output-side inductor 54 has a sixth portion 54e that is opposite to the fourth portion 52e of the second output-side inductor 52, separated from the second portion 42h of the second input-side inductor 42. The sixth portion 54e is located between the fifth portion 53d and the second shaft 62.

[0165] In the fifth part 53d, a third output current i5, based on the first input current i1, flows in the same direction as the first output current i3 flowing in the third part 51d of the first output-side inductor 51. The direction of the third output current i5 is the same as the direction of the first output current i3. In the sixth part 54e, a fourth output current i6, based on the second input current i2, flows in the same direction as the third output current i5, similar to the second output current i4 flowing in the fourth part 52e of the second output-side inductor 52.

[0166] The y-axis end of the protrusion 50ab in the upper inductor group 50a becomes the first output terminal 55a for generating the combined output current i7. This combined output current i7 is obtained by combining the currents induced by the first output-side inductor 51 and the third output-side inductor 53, and the currents induced by the second output-side inductor 52 and the fourth output-side inductor 54. The first output terminal 55a is connected to the output terminal 22 via a connecting conductive member 57a.

[0167] Therefore, the first output-side inductor 51 and the third output-side inductor 53 are connected in series, thus, the first output-side inductor 51 and the third output-side inductor 53 serve as output-side inductor 81 (see reference). Figure 1 To fulfill its function.

[0168] Similarly, the second output-side inductor 52 and the fourth output-side inductor 54 are connected in series, therefore, the second output-side inductor 52 and the fourth output-side inductor 54 serve as output-side inductor 82 (see reference). Figure 1 Then, the output signal RFout with the synthesized output current i7 is output from the output terminal 22.

[0169] [simulation]

[0170] The simulation of the current synthesis balancing-unbalancing converter 101 is explained.

[0171] Figure 6 This is the circuit diagram used in the simulation of the current synthesis balancing-unbalancing converter 101. (Example) Figure 6 As shown, signal source Src1 supplies the other end of the first input-side inductor 41, which is grounded at one end, with a signal obtained by combining the first amplified signal ARF1 and the second amplified signal ARF2 output by the first amplifier 31a and the second amplifier 31b, respectively.

[0172] Signal source Src2 supplies the other end of the second input-side inductor 42, which is grounded at one end, with a signal obtained by combining the third amplified signal ARF3 and the fourth amplified signal ARF4 output by the third amplifier 31c and the fourth amplifier 31d, respectively.

[0173] The signal source Src3 can supply signals to the other end of the output-side inductor 81, which is grounded at one end, and the other end of the output-side inductor 82, which is grounded at one end.

[0174] Figure 7 This is a graph showing an example of the frequency variation of the inductor observed from various signal sources. It should be noted that... Figure 7 In the diagram, the horizontal axis represents the frequency in "GHz" and the vertical axis represents the inductance in "nH".

[0175] like Figure 7 As shown, curve L1, for example, represents the frequency change of the inductance from signal source Src3 to ground. Curves L2 and L4, for example, represent the frequency changes of the inductance from signal source Src1 and signal source Src2 to ground.

[0176] For example, at 5 GHz, curves L1, L2, and L4 represent 1.30 nH, 0.48 nH, and 0.50 nH, respectively. Furthermore, curves L1, L2, and L4 exhibit small frequency variations and have inductance greater than zero, for example, in the frequency range below 6 GHz. That is, the first input-side inductor 41, the second input-side inductor 42, the output-side inductor 81, and the output-side inductor 82 function as inductors in the frequency range below 6 GHz, thus enabling the balun to function well in this frequency range.

[0177] Figure 8 This is a diagram illustrating an example of the frequency variation of the coupling coefficients of the transformers in the current-synthesizing balun 101. It should be noted that... Figure 8 In the diagram, the horizontal axis represents the frequency with the unit set to "GHz", and the vertical axis represents the coupling coefficient.

[0178] like Figure 8 As shown, curve k1, for example, represents the frequency variation of the coupling coefficient between the first input-side inductor 41 and the first output-side inductor 51 and the third output-side inductor 53. Curve k2, for example, represents the frequency variation of the coupling coefficient between the second input-side inductor 42 and the second output-side inductor 52 and the fourth output-side inductor 54.

[0179] The coupling coefficient is a coefficient with a maximum value of 1; the larger the value, the higher the conversion efficiency. In this embodiment, for example at 5 GHz, curves k1 and k2 represent 0.53 and 0.51, respectively. Therefore, the balun can convert differential signals into single-ended signals with good conversion efficiency.

[0180] [Second Implementation]

[0181] The differential amplifier device of the second embodiment will be described. From the second embodiment onwards, descriptions of aspects common to the first embodiment will be omitted, and only the differences will be explained. In particular, the same effects resulting from the same structure will not be mentioned repeatedly in each embodiment.

[0182] Figure 9 This is the circuit diagram of differential amplifier circuit 12. (Example) Figure 9 As shown, the differential amplifier circuit 12 of the second embodiment differs from the differential amplifier circuit 11 of the first embodiment in that it receives four differential signals.

[0183] Differential amplifier circuit 12 is a circuit located in the differential amplifier device, and... Figure 1 Compared to the differential amplifier circuit 11 shown, this circuit further includes a fifth amplifier 31e, a sixth amplifier 31f, a seventh amplifier 31g, an eighth amplifier 31h, and a current-synthesizing balun 1101. The current-synthesizing balun 1101 includes an input section 140 and an output section 150. The input section 140 includes a first input-side inductor 41 and a second input-side inductor 42. The output section 150 includes an output-side inductor 81 and an output-side inductor 82.

[0184] The differential amplifier circuit 12 amplifies the first to fourth differential signals respectively, and converts the amplified first to fourth differential signals into four single-ended signals. Then, the differential amplifier circuit 12 outputs the output signal RFout, which is obtained by combining these single-ended signals, from the output terminal 22.

[0185] Specifically, the third differential signal includes a fifth signal RF5 having approximately the same phase as the first signal RF1, and a sixth signal RF6 having approximately the same phase as the second signal RF2. Similarly, the fourth differential signal includes a seventh signal RF7 having approximately the same phase as the first signal RF1, and an eighth signal RF8 having approximately the same phase as the second signal RF2.

[0186] As described above, the phase of the first signal RF1 is approximately 180° different from the phase of the second signal RF2. Therefore, the phase difference between the fifth signal RF5 and the sixth signal RF6, and the phase difference between the seventh signal RF7 and the eighth signal RF8, are approximately 180°. The third and fourth differential signals are generated, for example, by a balun provided in the front stage of the differential amplifier circuit 12.

[0187] The fifth amplifier 31e, the sixth amplifier 31f, the seventh amplifier 31g and the eighth amplifier 31h are the same amplifiers as the first amplifier 31a, the second amplifier 31b, the third amplifier 31c and the fourth amplifier 31d.

[0188] The fifth amplifier 31e amplifies the fifth signal RF5 supplied through input terminal 21e and outputs the amplified fifth signal ARF5 from the output terminal. The sixth amplifier 31f amplifies the sixth signal RF6 supplied through input terminal 21f and outputs the amplified sixth signal ARF6 from the output terminal. The seventh amplifier 31g amplifies the seventh signal RF7 supplied through input terminal 21g and outputs the amplified seventh signal ARF7 from the output terminal. The eighth amplifier 31h amplifies the eighth signal RF8 supplied through input terminal 21h and outputs the amplified eighth signal ARF8 from the output terminal.

[0189] The current-synthesizing balun 1101 is the same balun 101 as the current-synthesizing balun 101, converting the third and fourth differential signals into two single-ended signals respectively. In the current-synthesizing balun 1101, the first input-side inductor 41 in the input section 140 has a first terminal 41a connected to the output terminal of the fifth amplifier 31e, a second terminal 41b connected to the output terminal of the sixth amplifier 31f, and a center tap 41c connected to the power supply voltage supply node N1 via the inductor 47. The fifth amplifier 31e and the sixth amplifier 31f amplify the voltage received from the power supply voltage supply node N1 through the inductor 47 and the center tap 41c.

[0190] The output-side inductor 81 in the output section 150 is mainly electromagnetically coupled to the first input-side inductor 41 in the input section 140, and generates an output current based on the electromagnetic field generated by the fifth amplified signal ARF5 and the sixth amplified signal ARF6 supplied to the first input-side inductor 41. The output current will be described in detail later. The output-side inductor 81 has a first terminal 81a connected to the output terminal 22 and a second terminal 81b grounded.

[0191] The second input-side inductor 42 in the input section 140 has a first terminal 42a connected to the output terminal of the seventh amplifier 31g, a second terminal 42b connected to the output terminal of the eighth amplifier 31h, and a center tap 42c connected to the power supply voltage supply node N1 via the inductor 47. The seventh amplifier 31g and the eighth amplifier 31h perform amplification using the voltage received from the power supply voltage supply node N1 through the inductor 47 and the center tap 42c.

[0192] The output-side inductor 82 in the output section 150 is primarily electromagnetically coupled to the second input-side inductor 42 in the input section 140, and an output current is generated based on the electromagnetic field generated by the seventh amplified signal ARF7 and the eighth amplified signal ARF8 supplied to the second input-side inductor 42. The output current will be described in detail later. The output-side inductor 82 has a first terminal 82a connected to the output terminal 22 and a second terminal 82b grounded.

[0193] [layout]

[0194] The layout of the differential amplifier circuit 12 is explained.

[0195] Figure 10 This is a diagram showing an example of the layout of input section 40 and input section 140. Figure 11 This is a diagram showing an example of the layout of the upper inductor group 50a and the upper inductor group 150a. Figure 12 This is a diagram showing an example of the layout of the lower inductor group 50b and the lower inductor group 150b. Figures 10-12 Observation methods and Figures 3-5 They are the same.

[0196] like Figures 10-12 As shown, the input section 140 is located on the x-axis side of the input section 40 (see reference). Figure 10 The first amplifier 31a, the second amplifier 31b, the third amplifier 31c, the fourth amplifier 31d, the fifth amplifier 31e, the sixth amplifier 31f, the seventh amplifier 31g, and the eighth amplifier 31h are arranged on the second layer in the following order: sixth amplifier 31f, fifth amplifier 31e, seventh amplifier 31g, eighth amplifier 31h, second amplifier 31b, first amplifier 31a, third amplifier 31c, and fourth amplifier 31d, facing the x-axis + side.

[0197] In the positive side extension 41d of the first input-side inductor 41 in the input section 140, more specifically in the first part 41h, a third input current i9 flows based on the fifth amplification signal ARF5 and the sixth amplification signal ARF6 supplied from the fifth amplifier 31e and the sixth amplifier 31f, respectively.

[0198] In the positive side extension 42d of the second input-side inductor 42 in the input section 140, more specifically in the second part 42h, a fourth input current i10 flows based on the seventh amplification signal ARF7 and the eighth amplification signal ARF8 supplied from the seventh amplifier 31g and the eighth amplifier 31h, respectively.

[0199] The phase of the first amplified signal ARF1 is approximately 180° different from the phase of the second amplified signal ARF2. Furthermore, the fifth amplified signal ARF5 and the sixth amplified signal ARF6 have approximately the same phase as the first amplified signal ARF1 and the second amplified signal ARF2, respectively. Therefore, the direction of the third input current i9 is the same as the direction of the first input current i1. Similarly, the seventh amplified signal ARF7 and the eighth amplified signal ARF8 have approximately the same phase as the first amplified signal ARF1 and the second amplified signal ARF2, respectively. Therefore, the direction of the fourth input current i10 is the same as the direction of the first input current i1.

[0200] Output section 150 includes an upper inductor group 150a identical to the upper inductor group 50a and a lower inductor group 150b identical to the lower inductor group 50b, and is disposed on the x-axis side of output section 50 (refer to...). Figure 11 and Figure 12 In detail, the upper inductor group 150a in the output section 150 is disposed on the x-axis side of the upper inductor group 50a and on the upper side of the input section 140 (see reference). Figure 10 and Figure 11 The lower inductor group 150b is located on the x-axis side of the lower inductor group 50b and below the input section 140 (see reference). Figure 10 and Figure 12 ).

[0201] The third part 51d in the upper inductor group 150a (see reference) Figure 11 The flow is based on the fifth output current i11, which is derived from the third input current i9. The direction of the fifth output current i11 is the same as the direction of the first output current i3 (refer to...). Figure 11 In the fourth part 52e, the sixth output current i12 flows in the same direction as the fifth output current i11, that is, in the same direction as the first output current i3, based on the fourth input current i10.

[0202] In the fifth part 53d of the lower inductor group 150b (see reference) Figure 12 The seventh output current i13 flows based on the third input current i9. The direction of the seventh output current i13 is the same as the direction of the first output current i3. In the sixth part 54e, the eighth output current i14 flows based on the fourth input current i10 in the same direction as the seventh output current i13, which is also the same direction as the first output current i3.

[0203] The first output terminal 55a in the upper inductor group 150a is connected to the output terminal 22 via the connecting conductive member 57d, node N2, and connecting conductive member 57a. The first output terminal 55a in the upper inductor group 150a outputs a composite output current i15, which is a current obtained by combining the current induced by the first output-side inductor 51 in the upper inductor group 150a and the third output-side inductor 53 in the lower inductor group 150b, as well as the current induced by the second output-side inductor 52 in the upper inductor group 150a and the fourth output-side inductor 54 in the lower inductor group 150b.

[0204] The first output terminal 55a in the upper inductor group 50a is connected to the output terminal 22 through the connecting conductive member 57c, node N2 and connecting conductive member 57a, and outputs the composite output current i7.

[0205] Then, an output signal RFout with a combined output current obtained by combining the combined output current i7 and the combined output current i15 is output from the output terminal 22.

[0206] [Third Implementation Method]

[0207] The differential amplifier device of the third embodiment will be described.

[0208] Figure 13 This is a diagram showing an example of the layout of the input section 240 in the current synthesis balancing / unbalancing converter 101. Figure 13 Observation methods and Figure 3 Same. For example... Figure 13 As shown, the input section 240 of the third embodiment differs from the input section 40 of the first embodiment in that the opening directions of the two U-shaped inductors are opposite to each other.

[0209] The current synthesis balancing / unbalancing converter 101 in this embodiment and Figure 3 Compared to the current synthesis balancing / unbalancing converter 101 shown, the input section 240 is included instead of the input section 40.

[0210] In this embodiment, the first input-side inductor 41 has a U-shaped opening in the second direction. The second input-side inductor 42 is disposed on the x-axis+ side of the first input-side inductor 41 and has a U-shaped opening in the third direction opposite to the second direction.

[0211] The first amplifier 31a and the second amplifier 31b are arranged in the order of the second amplifier 31b and the first amplifier 31a, on the y-axis+ side of the first input-side inductor 41 toward the x-axis+ side (see reference). Figure 13The third amplifier 31c and the fourth amplifier 31d are arranged in the order of the fourth amplifier 31d and the third amplifier 31c on the y-axis side of the second input-side inductor 42 toward the x-axis+ side.

[0212] The negative-side extension 42e in the second input-side inductor 42 is located on the y-axis + side of the fourth amplifier 31d and between the positive-side extension 41d in the first input-side inductor 41 and the second axis 62. The negative-side extension 42e has a shape that extends from the second end 42b connected to the output terminal of the fourth amplifier 31d toward the y-axis + side.

[0213] The positive extension 42d is located on the y-axis+ side of the third amplifier 31c, and is located on the opposite side of the negative extension 42e with reference to the second axis 62. The positive extension 42d has a shape that extends from the first end 42a connected to the output terminal of the third amplifier 31c toward the y-axis+ side.

[0214] The second input-side inductor 42 has a U-shaped overall shape with an upward opening on a third side from the y-axis + side toward the y-axis - side. In the negative-side extension 42e of the second input-side inductor 42, more specifically, in the second portion 42h located between the first portion 41h and the second axis 62, a second input current i2 flows based on the third amplified signal ARF3 and the fourth amplified signal ARF4 supplied from the third amplifier 31c and the fourth amplifier 31d, respectively.

[0215] The phase of the first amplified signal ARF1 is approximately 180° different from the phase of the second amplified signal ARF2. Furthermore, the third amplified signal ARF3 and the fourth amplified signal ARF4 have approximately the same phase as the first amplified signal ARF1 and the second amplified signal ARF2, respectively. Therefore, the direction of the second input current i2 is the same as the direction of the first input current i1.

[0216] [Reference Example]

[0217] The differential amplifier device of the reference example will be described.

[0218] Figure 14 This is a diagram illustrating an example of the layout of the input section 40 in a current-synthesizing balancing / unbalancing converter of a reference example. Figure 15 This is a diagram illustrating an example of the layout of the upper inductor group 90a in a current-synthesizing balancing / unbalancing converter of the reference example. Figure 14 and Figure 15 Observation methods and Figure 3 and Figure 4 same.

[0219] like Figure 14 and Figure 15As shown, in the differential amplifier device of the reference example, the first amplifier 31a, the second amplifier 31b, the third amplifier 31c, and the fourth amplifier 31d are arranged in the order of first amplifier 31a, second amplifier 31b, third amplifier 31c, and fourth amplifier 31d facing the x-axis + side, for example, on the second layer (refer to...). Figure 14 ).

[0220] The first terminal 41a and the second terminal 41b of the first input-side inductor 41 are connected to the output terminals of the second amplifier 31b and the first amplifier 31a, respectively. The first terminal 42a and the second terminal 42b of the second input-side inductor 42 are connected to the output terminals of the third amplifier 31c and the fourth amplifier 31d, respectively.

[0221] Therefore, the direction of the input current i91 flowing in the first part 41h of the first input-side inductor 41 is opposite to the direction of the input current i92 flowing in the second part 42h of the second input-side inductor 42.

[0222] Therefore, the direction of the magnetic field generated by the input current i91 inside the first input-side inductor 41 is the same as the direction of the magnetic field generated by the input current i92 inside the second input-side inductor 42.

[0223] That is, the direction of the magnetic field generated by the input current i91 inside the first input-side inductor 41 is opposite to the direction of the magnetic field generated by the input current i92 outside the second input-side inductor 42. Furthermore, the direction of the magnetic field generated by the input current i92 inside the second input-side inductor 42 is opposite to the direction of the magnetic field generated by the input current i91 outside the first input-side inductor 41.

[0224] That is, the magnetic field generated inside the first input-side inductor 41 by the input current i91 is weakened by the magnetic field generated outside the second input-side inductor 42 by the input current i92. Furthermore, the magnetic field generated inside the second input-side inductor 42 by the input current i92 is weakened by the magnetic field generated outside the first input-side inductor 41 by the input current i91.

[0225] The upper inductor group 90a will be described. The upper inductor group 90a is disposed on the first layer. The first output-side inductor 91 and the second output-side inductor 92 in the upper inductor group 90a are located above the first input-side inductor 41 and the second input-side inductor 42, respectively. The first output-side inductor 91 and the second output-side inductor 92 are wound in the same direction.

[0226] In detail, the first output-side inductor 91 has a first end 91a connected to the first output terminal 95a, and a second end 91b disposed at a position overlapping with the first shaft 61 and grounded. The second output-side inductor 92 has a first end 92a connected to the first output terminal 95a, and a second end 92b disposed at a position overlapping with the second shaft 62 and grounded.

[0227] When viewed from above the upper inductor group 90a from the z-axis+ side, the first output-side inductor 91 and the second output-side inductor 92 are wound counterclockwise.

[0228] In the first output-side inductor 91, an output current i93 based on the input current i91 flows in the third part 91d opposite to the first part 41h in the first input-side inductor 41.

[0229] In the second output-side inductor 92, the fourth portion 92e, which is opposite to the second portion 42h in the second input-side inductor 42, flows an output current i94 based on the input current i92 in the opposite direction to the output current i93. The first output terminal 95a outputs a combined output current i95, which is obtained by combining the output currents i93 and i94, to the output terminal 22.

[0230] It should be noted that a lower inductor group identical to the upper inductor group 90a is provided on the third layer, which outputs a combined output current identical to the combined output current i95 to the output terminal 22, which is not shown in the figure. An output signal RFout is output from the output terminal 22, which has a current obtained by combining the combined output current i95 and the combined output current from the lower inductor group.

[0231] [simulation]

[0232] The simulation of a current-synthesizing balancing-unbalancing converter for a reference example is illustrated. Using... Figure 6 The circuit shown was simulated in this way.

[0233] Figure 16 This is a graph showing an example of the frequency variation of an inductor in a reference example, as observed from various signal sources. It should be noted that... Figure 16 Observation methods and Figure 7 Same. For example... Figure 6 and Figure 16 As shown, curve L91, for example, represents the frequency change of the inductance up to ground when observed from signal source Src3. Curves L92 and L94, for example, represent the frequency changes of the inductance up to ground when observed from signal sources Srcl and Src2, respectively.

[0234] For example, at 5 GHz, curves L91, L92, and L94 represent 1.02 nH, 0.46 nH, and 0.44 nH, respectively. As mentioned above, since at 5 GHz, curves L1, L2, and L4 represent 1.30 nH, 0.48 nH, and 0.50 nH, respectively (refer to...) Figure 7 Therefore, compared with the current synthesis balancing converter of the reference example, the current synthesis balancing converter 101 can increase the inductance of each inductor constituting the current synthesis balancing converter 101.

[0235] Figure 17 This is a diagram illustrating an example of the frequency variation of the coupling coefficients of the transformers in a current-synthesizing balancing-unbalancing converter of a reference example. It should be noted that... Figure 17 Observation methods and Figure 8 same.

[0236] like Figure 17 As shown, curve k91, for example, represents the frequency variation of the coupling coefficient between the first input-side inductor 41 and the first output-side inductor 91 of the first layer and the first output-side inductor 91 of the third layer. Curve k92, for example, represents the frequency variation of the coupling coefficient between the second input-side inductor 42 and the second output-side inductor 92 of the first layer and the second output-side inductor 92 of the third layer.

[0237] For example, at 5 GHz, curves k91 and k92 represent 0.50 and 0.47, respectively. As mentioned above, since at 5 GHz, curves k1 and k4 represent 0.53 and 0.51, respectively (refer to...) Figure 8 Therefore, compared with the current synthesized balun in the reference example, the current synthesized balun 101 can convert the differential signal into a single-ended signal with good conversion efficiency.

[0238] It should be noted that the current synthesizing balancing converter 101 has been described with an upper inductor group 50a and a lower inductor group 50b respectively provided in the first and third layers, but it is not limited to this. In the current synthesizing balancing converter 101, it is also possible to use a structure that provides either the upper inductor group 50a in the first layer or the lower inductor group 50b in the third layer.

[0239] Furthermore, the structure in which the first surface 66, the second surface 67, and the third surface 68 intersect the first axis 61 and the second axis 62 approximately perpendicularly has been described, but it is not limited to this. The first surface 66, the second surface 67, or the third surface 68 may not intersect the first axis 61 and the second axis 62 approximately perpendicularly, as long as a structure intersecting the first axis 61 and the second axis 62 is adopted.

[0240] Furthermore, in the current synthesis balancing-unbalancing converter 101, a structure in which the first input-side inductor 41 is wound half a turn around the first shaft 61 has been described, but it is not limited to this. The first input-side inductor 41 may also have a structure in which it is wound more than one turn around the first shaft 61, or it may have a structure in which it is wound less than one turn around the first shaft 61.

[0241] Furthermore, in the current synthesis balancing-unbalancing converter 101, a structure in which the second input-side inductor 42 is wound half a turn around the second shaft 62 has been described, but it is not limited to this. The second input-side inductor 42 may also be wound more than one turn around the second shaft 62, or it may be wound less than one turn around the second shaft 62.

[0242] Furthermore, in the current synthesis balancing-unbalancing converter 101, a structure in which the first output-side inductor 51 and the third output-side inductor 53 are wound approximately one turn around the first shaft 61 has been described, but it is not limited to this. The first output-side inductor 51 or the third output-side inductor 53 may also have a structure in which more than one turn is wound around the first shaft 61, or a structure in which less than one turn is wound around the first shaft 61.

[0243] Furthermore, in the current synthesis balancing-unbalancing converter 101, a structure has been described in which the second output-side inductor 52 and the fourth output-side inductor 54 are wound approximately one turn around the second shaft 62, but this is not a limitation. The second output-side inductor 52 or the fourth output-side inductor 54 may also be wound with more than one turn around the second shaft 62, or they may be wound with less than one turn around the second shaft 62.

[0244] Furthermore, in the current-synthesizing balancing-unbalancing converter 101, a structure has been described with the first output-side inductor 51 and the fourth output-side inductor 54 wound clockwise and the second output-side inductor 52 and the third output-side inductor 53 wound counterclockwise when viewed from the z-axis+ side, but it is not limited to this. A structure in which the first output-side inductor 51 and the fourth output-side inductor 54 are wound counterclockwise and the second output-side inductor 52 and the third output-side inductor 53 are wound clockwise can also be used.

[0245] Furthermore, in the current synthesis balancing / unbalancing converter 101, a structure in which the second direction is approximately orthogonal to the first direction has been described, but it is not limited to this. The second direction may not necessarily adopt a structure that is approximately orthogonal to the first direction; a structure that intersects the first direction is sufficient.

[0246] Furthermore, in the differential amplifier circuit 12, a structure with two current-synthesizing baluns 101 arranged along the x-axis has been described, but it is not limited to this. The current-synthesizing baluns 101 may also have a structure with three or more arranged along the x-axis.

[0247] Furthermore, in the differential amplifier device, the structure of the current synthesizing balancing converter 101 that synthesizes the currents induced by the first output-side inductor 51, the second output-side inductor 52, the third output-side inductor 53, and the fourth output-side inductor 54 has been described, but it is not limited thereto. In the differential amplifier device, a structure of a voltage synthesizing balancing converter that synthesizes the voltages generated in the first output-side inductor 51, the second output-side inductor 52, the third output-side inductor 53, and the fourth output-side inductor 54 may also be adopted.

[0248] [Fourth Implementation Method]

[0249] The differential amplifier device of the fourth embodiment will be described.

[0250] Figure 18 This is the circuit diagram of differential amplifier circuit 13. (Example) Figure 18 As shown, the differential amplifier circuit 13 of the fourth embodiment differs from the differential amplifier circuit 11 of the first embodiment in that it synthesizes the voltage generated in the inductor on the output side.

[0251] Differential amplifier circuit 13 is a circuit located in the differential amplifier device, and... Figure 1 Compared to the differential amplifier circuit 11 shown, a voltage synthesizing balancing converter 301 is provided instead of the current synthesizing balancing converter 101. The voltage synthesizing balancing converter 301 and... Figure 1 Compared to the current synthesizing balancing / unbalancing converter 101 shown, the output section 50 is replaced by an output section 350. The output section 350 includes an output-side inductor 381 and an output-side inductor 382.

[0252] The output-side inductor 381 in the output section 350 is primarily electromagnetically coupled to the first input-side inductor 41, and generates an output voltage based on the electromagnetic field generated by the first amplified signal ARF1 and the second amplified signal ARF2 supplied to the first input-side inductor 41. The output voltage will be described in detail later. In this embodiment, the output-side inductor 381 has a first terminal 381a and a second terminal 381b connected to the output terminal 22. It should be noted that the output-side inductor 381 is obtained by connecting two inductors in series, which will be described in detail later.

[0253] The output-side inductor 382 in the output section 350 is primarily electromagnetically coupled to the second input-side inductor 42, and generates an output voltage based on the electromagnetic field generated by the third amplified signal ARF3 and the fourth amplified signal ARF4 supplied to the second input-side inductor 42. The output voltage will be described in detail later. In this embodiment, the output-side inductor 382 has a first terminal 382a connected to the first terminal of the output-side inductor 381 and a second terminal 382b grounded. It should be noted that the output-side inductor 382 is obtained by connecting two inductors in series, which will be described in detail later.

[0254] [layout]

[0255] Figure 19 This is a diagram showing an example of the layout of the upper inductor group 350a in the voltage synthesis balancing / unbalancing converter 301. Figure 20 This is a diagram illustrating an example of the layout of the lower inductor group 350b in the voltage synthesis balancing / unbalancing converter 301. Here, Figure 19 and Figure 20 Observation methods and Figure 4 and Figure 5 same.

[0256] like Figure 3 and Figures 18-20 As shown, the output section 350 includes an upper inductor group 350a and a lower inductor group 350b. The input section 40 (see reference) Figure 3 ) Set along the first face 66 (refer to Figure 2 The second layer. Figure 19 The upper inductor group 350a shown is disposed along the second surface 67 (see reference). Figure 2 The first layer. Figure 20 The lower inductor group 350b shown is disposed along the third surface 68 (refer to) Figure 2 The third layer of ).

[0257] Figure 19 The upper inductor group 350a shown includes a first output-side inductor 351 (first output-side conductive member) and a second output-side inductor 352 (second output-side conductive member). The lower inductor group 350b includes a third output-side inductor 353 (third output-side conductive member) and a fourth output-side inductor 354 (fourth output-side conductive member).

[0258] The first output-side inductor 351 in the upper inductor group 350a is located on the z-axis+ side of the first input-side inductor 41 and is wound around the first shaft 61. Specifically, when viewed from above the upper inductor group 350a from the z-axis+ side, the first output-side inductor 351 has a grounded first terminal 351a and a grounded second terminal 351b. In this top-view view, the first output-side inductor 351 is wound clockwise by less than 360° from the first terminal 351a to the second terminal 351b.

[0259] The second output-side inductor 352 is located on the z-axis+ side of the second input-side inductor 42. The second output-side inductor 352 is located on the x-axis+ side of the first output-side inductor 351 and is wound around the second shaft 62 along the winding direction of the first output-side inductor 351.

[0260] In detail, when viewed from the z-axis+ side of the upper inductor group 350a, the second output-side inductor 352 has a first end 352a connected to the second end 351b of the first output-side inductor 351, and a second end 352b disposed at a position overlapping with the second axis 62. In this top-view configuration, the second output-side inductor 352 is separated from the second axis 62 from the second end 352b to the first end 352a and wound clockwise approximately 360°. This structure shortens the overall length of the second output-side inductor 352.

[0261] The first output-side inductor 351 has a third portion 351d opposite to the first portion 41h in the first input-side inductor 41. The third portion 351d is located between the first shaft 61 and the second shaft 62.

[0262] The second output-side inductor 352 has a fourth portion 352e opposite to the second portion 42h in the second input-side inductor 42. The fourth portion 352e is located between the third portion 351d and the second shaft 62.

[0263] A first output current i3, based on a first input current i1, flows in the third part 351d. Specifically, through the change in the magnetic field generated primarily by the first input current i1 flowing in the first input-side inductor 41, an electric field is generated in the first output-side inductor 351 along the direction in which the first output-side inductor 351 is wound. This generated electric field produces a voltage between the first terminal 351a and the second terminal 351b of the first output-side inductor 351. Here, the potential of the second terminal 351b relative to the first terminal 351a, i.e., ground, is set to V1. Based on the voltage between the first terminal 351a and the second terminal 351b, the first output current i3 flows in the third part 351d.

[0264] In the fourth section 352e, a second output current i4, based on the second input current i2, flows in the same direction as the first output current i3. Specifically, through the change in the magnetic field generated primarily by the second input current i2 flowing through the second input-side inductor 42, an electric field is generated in the second output-side inductor 352 in the direction in which the second output-side inductor 352 is wound. This generated electric field produces a voltage between the first terminal 352a and the second terminal 352b of the second output-side inductor 352. Here, the potential of the second terminal 352b relative to the first terminal 352a is set to V2. As described above, since the direction of the magnetic field generated by the first input current i1 is opposite to the direction of the magnetic field generated by the second input current i2, in the fourth section 352e, the second output current i4 flows in the same direction as the first output current i3 through this electric field.

[0265] Figure 20 The third output-side inductor 353 and the fourth output-side inductor 354 in the lower inductor group 350b shown are wound in the opposite direction to the winding direction of the first output-side inductor 351 or the second output-side inductor 352 in the upper inductor group 350a.

[0266] Specifically, the fourth output-side inductor 354 in the lower inductor group 350b is located on the z-axis side of the second input-side inductor 42, and is wound around the second shaft 62 in a direction opposite to the winding direction of the first output-side inductor 351 or the second output-side inductor 352. Specifically, when viewed from the z-axis+ side, the fourth output-side inductor 354 has a first end 354a and a second end 354b located at a position overlapping the second shaft 62. In this top view, the fourth output-side inductor 354 is separated from the second shaft 62 from the first end 354a to the second end 354b and wound counterclockwise approximately 360°. The first end 354a is connected to the second end 352b of the second output-side inductor 352 via a through-hole 56b (see reference). Figure 2 and Figure 19 ).

[0267] The third output-side inductor 353 is located on the z-axis side of the first input-side inductor 41. The third output-side inductor 353 is located on the x-axis side of the fourth output-side inductor 354, and is wound around the first shaft 61 in a direction opposite to the winding direction of the first output-side inductor 351 or the second output-side inductor 352. In other words, the third output-side inductor 353 is wound around the first shaft 61 in the same direction as the fourth output-side inductor 354.

[0268] In detail, when viewed from the z-axis+ side, the lower inductor group 350b has a first end 353a connected to the second end 354b of the fourth output inductor 354, and a second end 353b disposed at a position overlapping with the first axis 61. In this top-view view, the third output inductor 353 is separated from the first axis 61 from the second end 353b to the first end 353a and wound counterclockwise approximately 360°.

[0269] The third output-side inductor 353 has a fifth portion 353d that is opposite to the third portion 351d of the first output-side inductor 351, separated from the first portion 41h of the first input-side inductor 41. The fifth portion 353d is located between the first shaft 61 and the second shaft 62.

[0270] The fourth output-side inductor 354 has a sixth portion 354e that is opposite to the fourth portion 352e of the second output-side inductor 352, separated from the second portion 42h of the second input-side inductor 42. The sixth portion 354e is located between the fifth portion 353d and the second shaft 62.

[0271] A fourth output current i6, based on the second input current i2, flows in the sixth part 354e. Specifically, through the change in the magnetic field generated primarily by the second input current i2 flowing in the second input-side inductor 42, an electric field is generated in the fourth output-side inductor 354 along the direction in which the fourth output-side inductor 354 is wound. This generated electric field produces a voltage between the first terminal 354a and the second terminal 354b of the fourth output-side inductor 354. Here, the potential of the second terminal 354b relative to the first terminal 354a, i.e., the second terminal 352b of the second output-side inductor 352, is set to V3. Based on the voltage between the first terminal 354a and the second terminal 354b, the fourth output current i6 flows in the fourth output-side inductor 354.

[0272] In the fifth part 353d, a third output current i5, based on the first input current i1, flows in the same direction as the fourth output current i6. Specifically, through the change in the magnetic field generated primarily by the first input current i1 flowing through the first input-side inductor 41, an electric field is generated in the third output-side inductor 353 in the direction in which the third output-side inductor 353 is wound. This generated electric field produces a voltage between the first terminal 353a and the second terminal 353b of the third output-side inductor 353. Here, the potential of the second terminal 353b relative to the first terminal 353a is set to V4. As described above, since the direction of the magnetic field generated by the first input current i1 is opposite to the direction of the magnetic field generated by the second input current i2, in the fifth part 353d, the third output current i5 flows in the same direction as the fourth output current i6 through this electric field.

[0273] Figure 19 The connecting conductive member 357a shown is a straight member extending along the y-axis when viewed from the z-axis+ side of the lower inductor group 350b. It has a first end that is connected to the second end 353b of the third output-side inductor 353 through a through-hole 56a, and a second end that becomes the output terminal 22.

[0274] Output terminal 22 outputs to the first output side inductor 351 (refer to...) Figure 19 ), second output-side inductor 352 (refer to) Figure 19 ), third output-side inductor 353 (refer to) Figure 20 ) and the fourth output-side inductor 354 (see reference) Figure 20 The combined output voltage is obtained by combining the voltages generated separately. Specifically, since the first output-side inductor 351, the second output-side inductor 352, the third output-side inductor 353, and the fourth output-side inductor 354 are connected in series, the output terminal 22 has a potential of (V1+V2+V3+V4) relative to ground.

[0275] Additionally, the first output-side inductor 351 and the second output-side inductor 352 serve as output-side inductor 381 (see reference). Figure 18 The second output-side inductor 352 and the fourth output-side inductor 354 function as output-side inductor 382 (see reference). Figure 18 To fulfill its function.

[0276] It should be noted that the voltage synthesis balancing-unbalancing converter 301 has been described with an upper inductor group 350a and a lower inductor group 350b respectively provided in the first and third layers, but it is not limited to this. In the voltage synthesis balancing-unbalancing converter 301, a structure may also be adopted in which only one of the upper inductor group 350a in the first layer and the lower inductor group 350b in the third layer is provided.

[0277] Furthermore, while the differential amplifier circuit 13 has been described with a structure that includes one voltage synthesizing balancing / unbalancing converter 301, it is not limited to this. Alternatively, two or more voltage synthesizing balancing / unbalancing converters 301 may be arranged along the x-axis.

[0278] Furthermore, in the differential amplifier circuit 13, the structure of the voltage synthesizing balun 301 with an input section 40 has been described, but it is not limited thereto. The voltage synthesizing balun 301 may also have an input section 240 instead of an input section 40 (see [reference]). Figure 13 The structure of ).

[0279] [Fifth Implementation]

[0280] The differential amplifier device of the fifth embodiment will be described.

[0281] Figure 21 This is the circuit diagram of differential amplifier circuit 14. (Example) Figure 21 As shown, the differential amplifier circuit 14 of the fifth embodiment differs from the differential amplifier circuit 13 of the fourth embodiment in that it has two differential pairs of driving stages provided in the pre-stages of the first amplifier 31a, the second amplifier 31b, the third amplifier 31c, and the fourth amplifier 31d.

[0282] Differential amplifier circuit 14 is a circuit located in the differential amplifier device, and... Figure 18 Compared to the differential amplifier circuit 13 shown, it also includes a balun 401, a first amplifier 131a, a second amplifier 131b, a third amplifier 131c, and a fourth amplifier 131d. The balun 401 has the same characteristics as... Figure 1 The current synthesis balancing / unbalancing converter 101 shown has the same structure.

[0283] The first amplifier 131a and the second amplifier 131b constitute the first drive stage differential pair. The third amplifier 131c and the fourth amplifier 131d constitute the second drive stage differential pair.

[0284] The first amplifier 31a and the second amplifier 31b form the first power stage differential pair. The third amplifier 31c and the fourth amplifier 31d form the second power stage differential pair.

[0285] The balun 401 is positioned between the two drive stage differential pairs and the two power stage differential pairs, functioning as an interstage matching circuit.

[0286] Specifically, the first amplifier 131a has an input terminal connected to the input terminal 21a and an output terminal connected to the first end 41a of the first input-side inductor 41 in the balun 401. The first amplifier 131a amplifies the first signal RF1 supplied to the input terminal through the input terminal 21a and outputs the amplified signal ARF9 from the output terminal.

[0287] The second amplifier 131b has an input terminal connected to the input terminal 21b and an output terminal connected to the second end 41b of the first input-side inductor 41 in the balun 401. The second amplifier 131b amplifies the second signal RF2 supplied to the input terminal through the input terminal 21b and outputs the amplified signal ARF10 from the output terminal.

[0288] The third amplifier 131c has an input terminal connected to the input terminal 21c and an output terminal connected to the first end 42a of the second input-side inductor 42 in the balun 401. The third amplifier 131c amplifies the third signal RF3 supplied to the input terminal through the input terminal 21c and outputs the amplified signal ARF11 from the output terminal.

[0289] The fourth amplifier 131d has an input terminal connected to the input terminal 21d and an output terminal connected to the second end 42b of the second input-side inductor 42 in the balun 401. The fourth amplifier 131d amplifies the fourth signal RF4 supplied to the input terminal through the input terminal 21d and outputs the amplified signal ARF12 from the output terminal.

[0290] The first terminal 81a and the second terminal 81b of the output-side inductor 81 in the balun 401 are connected to the input terminals of the first amplifier 31a and the second amplifier 31b, respectively. The first terminal 82a and the second terminal 82b of the output-side inductor 82 in the balun 401 are connected to the input terminals of the third amplifier 31c and the fourth amplifier 31d, respectively.

[0291] In this way, by configuring the balancing-unbalancing converter 401, which has a large coupling coefficient between inductors, as an inter-stage matching circuit, the impedance conversion ratio can be increased. Thus, even if the input impedance of the two power stage differential pairs is reduced to increase the output, for example, the impedance between the two drive stage differential pairs and the two power stage differential pairs can be well matched.

[0292] It should be noted that the differential amplifier circuit 14 has been described with respect to a structure in which a voltage combining balancing / unbalancing converter 301 is provided after the two power stage differential pairs, but it is not limited to this. In the differential amplifier circuit 14, a structure in which a current combining balancing / unbalancing converter 101 is provided after the two power stage differential pairs can also be adopted.

[0293] The exemplary embodiments of the present invention have been described above. The synthesized balun includes: a first input-side inductor 41 wound around the first shaft 61 on a first surface 66 intersecting the first shaft 61, and having a first portion 41h located between a second shaft 62 substantially parallel to the first shaft 61 and the first shaft 61, and allowing a first input current i1 to flow; and a second input-side inductor 42 wound around the second shaft 62 on the first surface 66, and having a second portion 42h located between the second shaft 62 and the first portion 41h, and allowing a second input current i2 to flow along the first shaft 61. The current i1 flows in the same direction as the input current i1; a first output-side inductor 51, which is wound around the first shaft 61 on a second surface 67 opposite to the first surface 66, and has a third portion 51d opposite to the first portion 41h; a second output-side inductor 52, which is wound around the second shaft 62 on the second surface 67, and has a fourth portion 52e opposite to the second portion 42h; and a first output terminal 55a, which outputs the current or voltage generated in the first output-side inductor 51 and the second output-side inductor 52 based on the first input current i1 and the second input current i2.

[0294] With this structure, the direction of the magnetic field generated by the first input current i1 on the inner side 41i of the first input-side inductor 41 is opposite to the direction of the magnetic field generated by the second input current i2 on the inner side 42i of the second input-side inductor 42. That is, the direction of the magnetic field generated by the first input current i1 on the inner side 41i of the first input-side inductor 41 is the same as the direction of the magnetic field generated by the second input current i2 on the outer side 42j of the second input-side inductor 42, and the direction of the magnetic field generated by the first input current i1 on the outer side 41j of the first input-side inductor 41 is the same as the direction of the magnetic field generated by the second input current i2 on the inner side 42i of the second input-side inductor 42. Therefore, the magnetic field generated by the first input current i1 on the inner side 41i of the first input-side inductor 41 is strengthened by the magnetic field generated by the second input current i2 on the outer side 42j of the second input-side inductor 42, and the magnetic field generated by the second input current i2 on the inner side 42i of the second input-side inductor 42 is strengthened by the magnetic field generated by the first input current i1 on the outer side 41j of the first input-side inductor 41. This increases the coupling coefficient between inductors in the synthesized balun, making the synthesized balun approximate an ideal transformer. This reduces leakage inductance, improves the impedance switching ratio of the synthesized balun, and suppresses the decrease in conversion efficiency from differential signals to single-phase signals. Furthermore, the synthesized balun can be used as an inter-stage matching circuit for impedance matching between two drive-stage differential pairs and two power-stage differential pairs. In this case, even if the impedances of the two drive stage differential pairs are significantly different from those of the two power stage differential pairs, the impedances between the two drive stage differential pairs and the two power stage differential pairs can still be well matched.

[0295] In addition, in the input section 40 of the current synthesis balancing-unbalancing converter 101, the first input-side inductor 41 and the second input-side inductor 42 have a U-shaped opening on the first surface 66 in a second direction that intersects the first direction from the first axis 61 toward the second axis 62.

[0296] In this way, by configuring the first input-side inductor 41 and the second input-side inductor 42 to have a U-shape with openings in the same direction, the first amplifier 31a, the second amplifier 31b, the third amplifier 31c, and the fourth amplifier 31d can be arranged on the first surface 66. This simplifies the wiring around each amplifier. Specifically, for example, it simplifies the wiring between the first amplifier 31a and the second amplifier 31b and the first input-side inductor 41, the wiring between the third amplifier 31c and the fourth amplifier 31d and the second input-side inductor 42, and the wiring between the preamplifier circuitry and each amplifier. Furthermore, it simplifies the configuration of each amplifier.

[0297] Furthermore, in the input section 240 of the differential amplifier circuit 11, the first input-side inductor 41 has a U-shape on the first surface 66 that opens in a second direction intersecting the first direction. Moreover, the second input-side inductor 42 has a U-shape that opens upwards in a third direction opposite to the second direction.

[0298] In this way, by configuring the first input-side inductor 41 and the second input-side inductor 42 to have U-shaped openings in opposite directions, for example, the first amplifier 31a and the second amplifier 31b can be configured on the y-axis+ side of the first input-side inductor 41, and the third amplifier 31c and the fourth amplifier 31d can be configured on the y-axis-side of the second input-side inductor 42.

[0299] In addition, in the differential amplifier circuit 11, the second input-side inductor 42 has a shape that is approximately symmetrical to the first input-side inductor 41 about a symmetry plane 63 located between the first axis 61 and the second axis 62.

[0300] This structure allows the magnetic field generated by the first input-side inductor 41 to be consistent with the magnetic field generated by the second input-side inductor 42. Therefore, it is easy to make the conversion characteristics from the first differential signal to a single-ended signal consistent with those from the second differential signal to a single-ended signal. Furthermore, it enables a compact overall configuration, allowing each inductor to be designed in a shape that maximizes its performance.

[0301] Furthermore, in the current-synthesizing balancing-unbalancing converter 101 of the differential amplifier circuit 11, the second output-side inductor 52 is wound around the second shaft 62 in a direction opposite to the winding direction of the first output-side inductor 51. A first output current i3 based on the first input current i1 flows in the third section 51d. A second output current i4 based on the second input current i2 flows in the fourth section 52e in the same direction as the first output current i3. Then, the first output terminal 55a outputs a synthesized output current i7 obtained by combining the first output current i3 and the second output current i4.

[0302] With this structure, it can function as a current synthesis balancing-unbalancing converter. The current synthesis balancing-unbalancing converter inputs the first input current i1 and the second input current i2, which constitute the differential signal, to the first input-side inductor 41 and the second input-side inductor 42, respectively, so that the synthesized output current i7 is output as a single-phase signal.

[0303] Furthermore, the current-synthesizing balancing-unbalancing converter 101 also includes: a third output-side inductor 53, which is wound around the first shaft 61 in the opposite direction on a third surface 68 opposite to the second surface 67 across the first surface 66, and has a fifth portion 53d opposite to the third portion 51d across the first portion 41h, and is connected in series with the first output-side inductor 51; and a fourth output-side inductor 54, which is wound around the second shaft 62 in the winding direction on the third surface 68, and has a sixth portion 54e opposite to the fourth portion 52e across the second portion 42h, and is connected in series with the second output-side inductor 52. A third output current i5 based on the first input current i1 flows in the fifth portion 53d. A fourth output current i6 based on the second input current i2 flows in the sixth portion 54e in the same direction as the third output current i5.

[0304] With this structure, the current supply capability of the current synthesis balancing-unbalancing converter 101 can be increased, and the coupling coefficient of the current synthesis balancing-unbalancing converter 101 can be increased, effectively suppressing the reduction in conversion efficiency from differential signal to single-phase signal.

[0305] In addition, in the differential amplifier circuit 11, the second output-side inductor 52 has a shape that is approximately symmetrical to the first output-side inductor 51 about a symmetry plane 63 located between the first axis 61 and the second axis 62.

[0306] This structure makes it easy to match the conversion characteristics from the first differential signal to the single-ended signal with those from the second differential signal to the single-ended signal, thus enabling a well-balanced output of the first output current i3 and the second output current i4. Furthermore, it allows for a compact overall configuration, enabling the inductors to be designed in shapes that maximize their performance.

[0307] Furthermore, in the voltage synthesizing balancing / unbalancing converter 301 of the differential amplifier circuit 13, the second output-side inductor 352 is wound along the winding direction of the first output-side inductor 351 and connected in series with the first output-side inductor 351. A first output current i3 based on the first input current i1 flows in the third portion 351d. A second output current i4 based on the second input current i2 flows in the fourth portion 352e in the same direction as the first output current i3. Then, the output terminal 22 outputs the synthesized output voltage obtained by combining the voltages generated by the first output-side inductor 351 and the second output-side inductor 352, respectively.

[0308] With this structure, it can function as a voltage synthesis balancing / unbalancing converter. The voltage synthesis balancing / unbalancing converter inputs the first input current i1 and the second input current i2, which constitute the differential signal, to the first input-side inductor 41 and the second input-side inductor 42, respectively, so that the synthesized output voltage is output as a single-phase signal.

[0309] Additionally, the voltage synthesizing balun 301 further comprises: a third output-side inductor 353, which is wound around the first shaft 61 in the opposite direction on a third surface 68 opposite to the second surface 67 across the first surface 66, and has a fifth portion 353d opposite to the third portion 351d across the first portion 41h, and is connected in series with the first output-side inductor 351; and a fourth output-side inductor 354, which is wound around the second shaft 62 in the opposite direction on the third surface 68, and has a sixth portion 354e opposite to the fourth portion 352e across the second portion 42h, and is connected in series with the first output-side inductor 351. The output terminal 22 outputs the synthesized output voltage obtained by combining the voltages generated by the first output-side inductor 351, the second output-side inductor 352, the third output-side inductor 353, and the fourth output-side inductor 354.

[0310] With this structure, the voltage output by the voltage synthesis balancing-unbalanced converter 301 can be increased, and the coupling coefficient of the voltage synthesis balancing-unbalanced converter 301 can be increased, effectively suppressing the reduction in conversion efficiency from differential signal to single-phase signal.

[0311] In addition, in the differential amplifier circuit 12, there are two groups of first input-side inductor 41, second input-side inductor 42, first output-side inductor 51, second output-side inductor 52 and first output terminal 55a arranged along the first direction.

[0312] With this structure, the first to fourth differential signals can be converted into four single-ended signals, which are then combined and output. This reduces the load on each amplifier, thereby increasing the output of the differential amplifier circuit 12. Furthermore, for example, by reducing the load on each amplifier while maintaining the same power output as the differential amplifier circuit 11 which includes four amplifiers, the output impedance observed from the amplifiers can be increased. This, in turn, increases the output voltage of each amplifier. That is, compared to the amplifiers included in the differential amplifier circuit 11, the gain of each amplifier included in the differential amplifier circuit 12 can be increased.

[0313] Additionally, the differential amplifier includes: a first amplifier 31a that amplifies a first signal RF1 and outputs a first amplified signal ARF1; a second amplifier 31b that amplifies a second signal RF2 having a different phase from the first signal RF1 and outputs a second amplified signal ARF2; a third amplifier 31c that amplifies a third signal RF3 having approximately the same phase as the first signal RF1 and outputs a third amplified signal ARF3; a fourth amplifier 31d that amplifies a fourth signal RF4 having approximately the same phase as the second signal RF2 and outputs a fourth amplified signal ARF4; and a first input-side inductor 41 wound around the first shaft 61 on a first surface 66 intersecting the first shaft 61, and having a first end 41a connected to the first amplifier 31a, a first portion 41h located between a second shaft 62, which is approximately parallel to the first shaft 61, and allowing a first input current i1 to flow, and a second end 41h connected to the second amplifier 31b. Two terminals 41b; a second input-side inductor 42 wound around a second shaft 62 on a first surface 66, having a first terminal 42a connected to a third amplifier 31c, a second portion 42h located between the second shaft 62 and a first portion 41h that allows the second input current i2 to flow in the same direction as the first input current i1, and a second terminal 42b connected to a fourth amplifier 31d; a first output-side inductor 51 wound around a first shaft 61 on a second surface 67 opposite to the first surface 66, having a third portion 51d opposite to the first portion 41h; a second output-side inductor 52 wound around a second shaft 62 on a second surface 67, having a fourth portion 52e opposite to the second portion 42h; and a first output terminal 55a that outputs the current or voltage generated in the first output-side inductor 51 and the second output-side inductor 52 based on the first input current i1 and the second input current i2.

[0314] With this structure, the direction of the magnetic field generated by the first input current i1 on the inner side 41i of the first input-side inductor 41 is opposite to the direction of the magnetic field generated by the second input current i2 on the inner side 42i of the second input-side inductor 42. That is, the direction of the magnetic field generated by the first input current i1 on the inner side 41i of the first input-side inductor 41 is the same as the direction of the magnetic field generated by the second input current i2 on the outer side 42j of the second input-side inductor 42, and the direction of the magnetic field generated by the first input current i1 on the outer side 41j of the first input-side inductor 41 is the same as the direction of the magnetic field generated by the second input current i2 on the inner side 42i of the second input-side inductor 42. Therefore, the magnetic field generated by the first input current i1 on the inner side 41i of the first input-side inductor 41 is strengthened by the magnetic field generated by the second input current i2 on the outer side 42j of the second input-side inductor 42, and the magnetic field generated by the second input current i2 on the inner side 42i of the second input-side inductor 42 is strengthened by the magnetic field generated by the first input current i1 on the outer side 41j of the first input-side inductor 41. This increases the coupling coefficient between inductors in the synthesized balun, making the synthesized balun approximate an ideal transformer. This reduces leakage inductance, improves the impedance switching ratio of the synthesized balun, and suppresses the decrease in conversion efficiency from differential signals to single-phase signals. Furthermore, the synthesized balun can be used as an inter-stage matching circuit for impedance matching between two drive-stage differential pairs and two power-stage differential pairs. In this case, even if the impedances of the two drive stage differential pairs are significantly different from those of the two power stage differential pairs, the impedances between the two drive stage differential pairs and the two power stage differential pairs can still be well matched.

[0315] Furthermore, the first and second differential signals can be converted into two single-ended signals respectively, and then combined and output. This reduces the load on each amplifier, thus increasing the output of the differential amplifier. Additionally, for example, by reducing the load on each amplifier while maintaining the same power output as a differential amplifier circuit comprising two amplifiers, the output impedance observed from the amplifiers can be increased. This, in turn, increases the output voltage of each amplifier. In other words, compared to the amplifiers included in the aforementioned differential amplifier circuit, the gain of each amplifier included in the differential amplifier can be increased.

[0316] It should be noted that the embodiments described above are for the purpose of facilitating understanding of the present invention, and are not intended to limit the interpretation of the present invention. The present invention can be modified / improved without departing from its spirit, and the present invention also includes its equivalents. That is, embodiments obtained by those skilled in the art through appropriate design modifications to the embodiments, as long as they possess the features of the present invention, are also included within the scope of the present invention. For example, the elements, their configurations, materials, conditions, shapes, dimensions, etc., of each embodiment are not limited to the illustrative content and can be appropriately modified. Furthermore, each embodiment is illustrative, and of course, partial substitutions or combinations of the structures shown in different embodiments are possible; as long as they possess the features of the present invention, they are also included within the scope of the present invention.

Claims

1. A synthetic balancing-unbalancing converter, comprising: A first input-side conductive member is wound around the first axis on a first surface intersecting the first axis, and has a first portion located between the first axis and a second axis parallel to the first axis, and allows a first input current to flow. A second input-side conductive member is wound around the second shaft on the first surface and has a second portion located between the second shaft and the first portion, and allows the second input current to flow in the same direction as the first input current. A first output-side conductive member is wound around the first shaft on a second surface opposite to the first surface, and has a third portion opposite to the first portion. A second output-side conductive member is wound around the second shaft on the second surface and has a fourth portion opposite to the second portion; as well as The output terminal outputs the current or voltage generated in the first output-side conductive member and the second output-side conductive member based on the first input current and the second input current.

2. The synthetic balancing / unbalancing converter according to claim 1, wherein, The first input-side conductive member and the second input-side conductive member have a U-shaped opening on the first surface in a second direction that intersects a first direction from the first axis toward the second axis.

3. The synthetic balancing / unbalancing converter according to claim 1, wherein, The first input-side conductive member has a U-shape on the first surface that opens in a second direction intersecting a first direction from the first axis toward the second axis. The second input-side conductive member has a U-shape that opens upwards in a third direction opposite to the second direction.

4. The synthetic balancing / unbalancing converter according to claim 1 or 2, wherein, The second input-side conductive member has a shape that is symmetrical to the first input-side conductive member about a symmetrical plane located between the first axis and the second axis.

5. The synthesis balancer / unbalancer according to any one of claims 1 to 3, wherein, The second output-side conductive member is wound in a direction opposite to the winding direction of the first output-side conductive member. A first output current flows in the third part based on the first input current. In the fourth part, a second output current based on the second input current flows in the same direction as the first output current. The output terminal outputs a combined output current obtained by combining the first output current and the second output current.

6. The synthetic balancing / unbalancing converter according to claim 5, wherein, The synthetic balancing-unbalancing converter also features: A third output-side conductive member is wound around the first shaft in the opposite direction on a third surface that faces the second surface across the first surface, and has a fifth portion that faces the third portion across the first portion, and is connected in series with the first output-side conductive member. as well as A fourth output-side conductive member is wound around the second shaft along the winding direction on the third surface, and has a sixth portion opposite the fourth portion, separated from the second portion, and connected in series with the second output-side conductive member. A third output current flows in the fifth section based on the first input current. In the sixth section, a fourth output current based on the second input current flows in the same direction as the third output current.

7. The synthetic balancing / unbalancing converter according to claim 5, wherein, The second output-side conductive member has a shape that is symmetrical to the first output-side conductive member about a symmetrical plane located between the first axis and the second axis.

8. The synthesis balancer / unbalancer according to any one of claims 1 to 3, wherein, The second output-side conductive member is wound along the winding direction of the first output-side conductive member and connected in series with the first output-side conductive member. A first output current flows in the third part based on the first input current. In the fourth part, a second output current based on the second input current flows in the same direction as the first output current. The output terminal outputs a combined output voltage obtained by combining the voltages generated by the first output-side conductive member and the second output-side conductive member, respectively.

9. The synthetic balancing / unbalancing converter according to claim 8, wherein, The synthetic balancing-unbalancing converter also features: The third output-side conductive member is wound around the first shaft in the opposite direction of the winding direction on a third surface that faces the second surface across the first surface, and has a fifth portion that faces the third portion across the first portion, and is connected in series with the first output-side conductive member. as well as A fourth output-side conductive member is wound around the second shaft in the opposite direction on the third surface, and has a sixth portion opposite the fourth portion separated from the second portion, and is connected in series with the first output-side conductive member. The output terminal outputs a composite output voltage obtained by combining the voltages generated by the first output-side conductive member, the second output-side conductive member, the third output-side conductive member, and the fourth output-side conductive member.

10. The synthetic balancing / unbalancing converter according to any one of claims 1 to 3, wherein, The first input-side conductive member, the second input-side conductive member, the first output-side conductive member, the second output-side conductive member, and the output terminal are arranged in a plurality of groups along a first direction from the first axis toward the second axis.

11. A differential amplifier, comprising: The first amplifier amplifies the first signal and outputs the first amplified signal. The second amplifier amplifies a second signal having a different phase from the first signal and outputs a second amplified signal. A third amplifier amplifies a third signal having the same phase as the first signal and outputs a third amplified signal. A fourth amplifier amplifies a fourth signal having the same phase as the second signal and outputs a fourth amplified signal. A first input-side conductive member is wound around the first axis on a first surface intersecting the first axis, and has a first end connected to the first amplifier, a first portion located between the first axis and a second axis parallel to the first axis and allowing the first input current to flow, and a second end connected to the second amplifier. The second input-side conductive member is wound around the second shaft on the first surface and has a first end connected to the third amplifier, a second portion located between the second shaft and the first portion and causing the second input current to flow in the same direction as the first input current, and a second end connected to the fourth amplifier. A first output-side conductive member is wound around the first shaft on a second surface opposite to the first surface, and has a third portion opposite to the first portion. A second output-side conductive member is wound around the second shaft on the second surface and has a fourth portion opposite to the second portion; as well as The output terminal outputs the current or voltage generated in the first output-side conductive member and the second output-side conductive member based on the first input current and the second input current.

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