Balun

Abstract

The present application provides a kind of balanced-unbalanced transformer that can match the impedance between the circuit of front stage and the circuit of rear stage in wider frequency band.The balanced-unbalanced transformer has: the first wiring, with the first end connected with the first balance line of one of transmission balanced signal and the second end connected with the second balance line of another of transmission balanced signal;The second wiring has the first end grounded and the second end;The third wiring has the first end connected with the second end of the second wiring and the second end connected with the unbalanced line of transmission unbalanced signal, and is electromagnetically coupled with the second wiring;The first capacitor has the first end connected with the first end of the third wiring and the second end grounded;And the second capacitor has the first end connected with the second end of the third wiring and the second end grounded, and the first wiring is electromagnetically coupled with at least one of the second wiring and the third wiring.

Description

Technical Field

[0001] This invention relates to balanced-unbalanced converters. Background Technology

[0002] There are semiconductor devices that integrate a differential power amplifier, a transmit matching circuit, and a transmit filter into a single semiconductor integrated circuit (for example, see Patent Document 1).

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2016-158053

[0006] Patent Document 2: US Patent No. 9,584,076

[0007] In the semiconductor device described in Patent Document 1, a transmission matching circuit (balanced-to-unbalanced converter) that performs impedance transformation and balanced-to-unbalanced transformation of the transmitted signal and a filter that attenuates the signal in the cutoff band are provided in the stage after the differential power amplifier.

[0008] However, in the circuit structure described in Patent Document 1, the frequency variation of the load impedance when observing the subsequent circuit from the output of the differential power amplifier sometimes becomes large regarding the fundamental frequency of the radio frequency (RF) signal. That is, there is a problem of a narrow bandwidth that allows for good impedance matching between the differential power amplifier and the subsequent circuit. Summary of the Invention

[0009] The problem the invention aims to solve

[0010] The present invention was made in view of the following circumstances, and its object is to provide a balun that can achieve good impedance matching between the circuitry of the preceding stage and the circuitry of the following stage over a wide frequency band.

[0011] means for solving problems

[0012] One aspect of the present invention relates to a balun comprising: a first wiring having a first terminal connected to a first balanced line transmitting a balanced signal and a second terminal connected to a second balanced line transmitting the other balanced signal; a second wiring having a first terminal and a second terminal, the first terminal being grounded; a third wiring having a first terminal connected to the second terminal of the second wiring and a second terminal connected to an unbalanced line transmitting an unbalanced signal, and electromagnetically coupled to the second wiring; a first capacitor having a first terminal connected to the first terminal of the third wiring and a grounded second terminal; and a second capacitor having a first terminal connected to the second terminal of the third wiring and a grounded second terminal, wherein the first wiring is electromagnetically coupled to at least one of the second wiring and the third wiring.

[0013] Invention Effects

[0014] According to the present invention, a balun is provided that can provide good impedance matching between the circuitry of the preceding stage and the circuitry of the following stage over a wide frequency band. Attached Figure Description

[0015] Figure 1 This is the circuit diagram of power amplifier circuit 111.

[0016] Figure 2 This is a circuit diagram of the power amplifier circuit 91, which serves as the first reference example.

[0017] Figure 3 This is a diagram illustrating an example of the simulation results for the impedance Gin1 in the power amplifier circuit 111.

[0018] Figure 4 This is a diagram illustrating an example of the simulation results for the impedance Gin2 in the power amplifier circuit 111.

[0019] Figure 5 This is a diagram illustrating an example of the simulation results for the impedance Gin3 in the power amplifier circuit 91.

[0020] Figure 6 This is a diagram illustrating an example of the simulation results for the impedance Gin4 in the power amplifier circuit 91.

[0021] Figure 7 This is a figure illustrating an example of the simulation results for the return loss in power amplifier circuit 111.

[0022] Figure 8 This is a diagram illustrating an example of the simulation results of power loss in power amplifier circuit 111.

[0023] Figure 9 This is a figure illustrating an example of the simulation results for the return loss in the power amplifier circuit 91.

[0024] Figure 10 This is a diagram illustrating an example of the simulation results of power loss in power amplifier circuit 91.

[0025] Figure 11 This is a diagram illustrating an example of the simulation results for all losses in power amplifier circuit 111.

[0026] Figure 12 This is a diagram illustrating an example of the simulation results for all losses in the power amplifier circuit of the second reference example.

[0027] Figure 13 This is a figure illustrating an example of the simulation results for all losses in the power amplifier circuit of the third reference example.

[0028] Figure 14 This is a diagram schematically showing the layout of the balanced-unbalanced converter 101.

[0029] Figure 15 This is a diagram schematically showing the layout of the balanced-unbalanced converter 101A.

[0030] Figure 16 This is a diagram schematically showing the layout of the balanced-unbalanced converter 101B.

[0031] Figure 17 This is a diagram schematically showing the layout of the balanced-unbalanced converter 101C.

[0032] Figure 18 This is the circuit diagram of power amplifier circuit 115.

[0033] Figure 19 This is a diagram schematically showing the layout of the balanced-unbalanced converter 103.

[0034] Explanation of reference numerals in the attached figures

[0035] 1…semiconductor devices;

[0036] 31, 31p, 31m… Input terminals;

[0037] 32, 32p, 32m… output terminals;

[0038] 101, 101A, 101B, 101C, 103… Balanced-to-unbalanced converters;

[0039] 111, 115… power amplifier circuits;

[0040] 151p, 151m... amplifiers;

[0041] 201… axis;

[0042] 211, 212, 213, 214, 215… wiring layers;

[0043] Surfaces 211a, 212a, 213a, 214a, 215a…

[0044] Transformers 301, 302…

[0045] 311, 312, 313, 314, 315… windings;

[0046] 331, 332, 333, 334, 335… capacitors;

[0047] 501p, 501m... balanced circuits;

[0048] 601…unbalanced circuit;

[0049] 701, 702, 703, 704, 705… Metal wiring;

[0050] 703a, 703b, 703c, 703d, 703e, 703f… Metal wiring;

[0051] 7031, 7032, 7033, 7034… Metal wiring;

[0052] 723, 733, 734, 745... Interlayer vias. Detailed Implementation

[0053] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, the same reference numerals will be used to label the same elements, and repeated descriptions will be omitted as much as possible.

[0054] [First Implementation]

[0055] The balun 101 and power amplifier circuit 111 according to the first embodiment will be described. Figure 1 This is the circuit diagram of power amplifier circuit 111. (For example...) Figure 1 As shown, semiconductor device 1 includes power amplifier circuit 111. Semiconductor device 1 is, for example, a semiconductor chip in which power amplifier circuit 111 is formed. Power amplifier circuit 111 is a circuit that amplifies a balanced radio frequency signal and outputs an unbalanced signal.

[0056] The power amplifier circuit 111 includes a balun 101, amplifiers 151p and 151m, and capacitor 333. The balun 101 includes a transformer 301, capacitor 331 (first capacitor), and capacitor 332 (second capacitor). The transformer 301 includes windings 311 (first wiring), 312 (second wiring), and 313 (third wiring). Amplifiers 151p and 151m, for example, constitute a differential pair in the primary (driver stage). Amplifier 151m has input-output characteristics substantially the same as those of amplifier 151p.

[0057] In this embodiment, amplifiers 151p and 151m are constructed from bipolar transistors such as heterojunction bipolar transistors (HBTs). Alternatively, amplifiers 151p and 151m can also be constructed from other transistors such as metal-oxide-semiconductor field-effect transistors (MOSFETs). In this case, simply rewriting the base, collector, and emitter as gate, drain, and source, respectively.

[0058] At input terminals 31p and 31m, a signal RFp1, serving as one of the balancing signals, and a signal RFm1, serving as the other of the balancing signals, are respectively input. The phases of signal RFp1 and signal RFm1 are different. In this embodiment, the phase difference between signal RFp1 and signal RFm1 is approximately 180°. However, due to uneven wiring lengths in the circuit, the phase difference may sometimes differ significantly from 180°.

[0059] Amplifier 151p has an input terminal 151pa that receives signal RFp1 through input terminal 31p, and an output terminal 151pb that outputs an amplified signal RFp2 that amplifies signal RFp1. Amplifier 151m has an input terminal 151ma that receives signal RFm1 through input terminal 31m, and an output terminal 151mb that outputs an amplified signal RFm2 that amplifies signal RFm1.

[0060] One of the balanced signals, namely the amplified signal RFp2, is transmitted to the balun 101 via the balanced line 501p (the first balanced line). The other balanced signal, namely the amplified signal RFm2, is transmitted to the balun 101 via the balanced line 501m (the second balanced line).

[0061] The winding 311 in the balun 101 has a first terminal connected to the output terminal 151pb of the amplifier 151p via the balun line 501p, and a second terminal connected to the output terminal 151mb of the amplifier 151m via the balun line 501m.

[0062] Capacitor 333 has a first terminal connected to a first terminal of winding 311 and a second terminal connected to a second terminal of winding 311. Winding 312 has a first terminal and a second terminal that are grounded and is electromagnetically coupled to winding 311.

[0063] Winding 313 has a first end and a second end connected to the second end of winding 312, and is electromagnetically coupled to winding 312. Capacitor 331 has a first end connected to the first end of winding 313 and a second end grounded. Capacitor 332 has a first end connected to the second end of winding 313 and a second end grounded.

[0064] The amplified signals RFp2 and RFm2, which are balanced signals, are converted into the output signal RF3, which is an unbalanced signal, by the balanced-unbalanced converter 101 and output from the second end of the winding 313.

[0065] The unbalanced line 601 connects the second end of the winding 313 to the output terminal 32. In the unbalanced line 601, the output signal RF3 output from the second end of the winding 313 is transmitted to the output terminal 32.

[0066] [First Reference Example]

[0067] The power amplifier circuit 91, which serves as the first reference example, will be described. Figure 2 This is a circuit diagram of a power amplifier circuit 91 as a first reference example. Such a circuit is described, for example, in Patent Document 1. The amplifier PA13 is composed of a differential power amplifier that incorporates FETs (Field-effect transistors). Furthermore, the amplifier PA13 has input terminals T1p and T1m, and output terminals T13p and T13m connected to the transmitter 12.

[0068] The transmission matching circuit TR41 includes an inductor L42 and a capacitor C43 forming the balanced side, and an inductor L44 forming the unbalanced side. Inductor L42 has a first terminal connected to output terminal T13p and a second terminal connected to output terminal T13m. Capacitor C43 is connected between the first and second terminals of inductor L42. Inductor L44 has a first terminal grounded and a second terminal connected to switch 23 via output terminal T2.

[0069] Capacitor C45 has a first terminal connected to the second terminal of inductor L44 and a second terminal grounded. Filter LPF46 includes inductor L47 and capacitor C48. Inductor L47 has a first terminal connected to the second terminal of inductor L44 and a second terminal. Capacitor C48 has a first terminal connected to the second terminal of inductor L47 and a second terminal grounded.

[0070] [Frequency variation of impedance]

[0071] The frequency variations of impedances Gin1 to Gin4 are explained. Here, impedances Gin1 and Gin2 are in power amplifier circuit 111 (refer to...). Figure 1 The impedance at output terminal 32 is observed from output terminals 151pb and 151mb respectively. Impedances Gin3 and Gin4 are in the power amplifier circuit 91 (refer to...). Figure 2 The impedance at output terminal T2 is observed from output terminals T13p and T13m respectively.

[0072] The inventors used the circuit constants of each circuit element in power amplifier circuits 111 and 90 as parameters to simulate the frequency variations of impedances Gin1 to Gin4. For example, the inventors optimized the parameters in a frequency range of approximately 1.7 GHz to 2.7 GHz, making impedances Gin1 and Gin2 close to fixed real values. Similarly, the inventors optimized the parameters in the same frequency range, making impedances Gin3 and Gin4 close to fixed real values.

[0073] Figure 3 as well as Figure 4 The power amplifier circuit 111 is shown below (see reference). Figure 1 A figure showing an example of the simulation results for impedances Gin1 and Gin2 in (). Figure 3 In the diagram, curve G1 is shown on the Smith chart. Curve G1 illustrates the change in impedance Gin1 when the characteristic impedance is set to, for example, 6 ohms, as the frequency of signal RFp1 varies from 1.2 GHz to 9.0 GHz. In curve G1, the change in impedance Gin1 over the frequency range of 1.7 GHz to 2.7 GHz is a clockwise trajectory from position g11 to position g12.

[0074] exist Figure 4 In the diagram, curve G2 is shown on the Smith chart. Curve G2 illustrates the change in impedance Gin2 when the characteristic impedance is set to, for example, 6 ohms, as the frequency of the signal RFml varies from 1.2 GHz to 9.0 GHz. In curve G2, the change in impedance Gin2 over the frequency range of 1.7 GHz to 2.7 GHz is a clockwise trajectory from position g21 to position g22.

[0075] Figure 5 as well as Figure 6 The power amplifier circuit 91 is shown below (see reference). Figure 2 A figure showing an example of the simulation results for impedances Gin3 and Gin4 in (). Figure 5 In the diagram, curve G3 is shown on the Smith chart. Curve G3 illustrates the change in impedance Gin3 as the frequency of the signal input to input terminal T1p varies from 1.2 GHz to 9.0 GHz. In curve G3, the change in impedance Gin3 over the frequency range of 1.7 GHz to 2.7 GHz is a clockwise trajectory from position g31 to position g32.

[0076] exist Figure 6 In the diagram, curve G4 is shown on the Smith chart. Curve G4 illustrates the change in impedance Gin4 as the frequency of the signal input to input terminal T1m varies from 1.2 GHz to 9.0 GHz. In curve G4, the change in impedance Gin4 over the frequency range of 1.7 GHz to 2.7 GHz is a clockwise trajectory from position g41 to position g42.

[0077] like Figures 3-6 As shown, in the frequency range from 1.7 GHz to 2.7 GHz, curves G1 and G2 are located near the center of the Smith chart compared to curves G3 and G4. That is, in power amplifier circuit 111, compared to power amplifier circuit 91, the frequency variations of impedances Gin1 and Gin2 can be suppressed well.

[0078] [Frequency variation of return loss]

[0079] The frequency variation of the return loss at the output terminal of the differential amplifier is explained. Figure 7 This shows the power amplifier circuit 111 (reference). Figure 1 A figure showing an example of the simulation results for return loss in (). Additionally, in Figure 7 In the diagram, the horizontal axis shows the frequency in "GHz" and the vertical axis shows the return loss in "dB".

[0080] Curves L1 and L2 show the frequency variations of the return loss at output terminals 151pb and 151mb, respectively. Here, the return loss at output terminal 151pb is, for example, 20 × log(|Gin1|), where |Gin1| represents the absolute value of the impedance Gin1. Similarly, the return loss at output terminal 151mb is, for example, 20 × log(|Gin2|).

[0081] The smaller the return loss, the better the impedance matching of the balun 101. For example, if the impedance (especially the impedance Gin1) is well matched when the return loss is below -20, then in the power amplifier circuit 111, the balun 101 can achieve good impedance matching over a wide frequency range of 1.2 GHz from 1.55 GHz to 2.75 GHz.

[0082] Figure 9 This shows the power amplifier circuit 91 (reference). Figure 2 A figure showing an example of the simulation results for return loss in [the context of the simulation]. Additionally, Figure 9 The representation method and Figure 7 same.

[0083] Curves L3 and L4 show the frequency variations of the return loss at output terminals T13p and T13m, respectively. The return losses at output terminals T13p and T13m are, for example, 20×log(|Gin3|) and 20×log(|Gin4|).

[0084] If impedance is well matched when the return loss is below -20, then in power amplifier circuit 91, the frequency range in which impedance (especially impedance Gin3) can be well matched becomes a narrower frequency range of 0.75 GHz from 1.7 GHz to 2.45 GHz. That is, in power amplifier circuit 111, impedance can be well matched over a wider frequency range compared to power amplifier circuit 91.

[0085] [Frequency variation of power loss]

[0086] The frequency variation of power loss between the output terminals of the differential amplifier and the output terminals of the power amplifier circuit is explained. Figure 8 This shows the power amplifier circuit 111 (reference). Figure 1 A figure illustrating an example of simulation results for power loss in [the context of the simulation]. Additionally, in [the context of the simulation results]... Figure 8 In the diagram, the horizontal axis shows the frequency in "GHz" and the vertical axis shows the power loss in "dBm".

[0087] Curve L11 shows the frequency variation of power loss between output terminal 151pb and output terminal 32. Here, this power loss is represented by P1-Pout1+3, where P1 and Pout1 are the output power of amplifier 151pb and the output power of output terminal 32, respectively.

[0088] Curve L12 shows the frequency variation of power loss between output terminal 151mb and output terminal 32. Here, this power loss is P2 - Pout1 + 3. P2 is the output power of amplifier 151m. Furthermore, the units for P1, P2, and Pout1 are "dBm".

[0089] Figure 10 This shows the power amplifier circuit 91 (reference). Figure 2 A figure showing an example of the simulation results for power loss in [the context of the simulation]. Additionally, Figure 10 The representation method and Figure 8 same.

[0090] Curve L13 shows the frequency variation of power loss between output terminals T13p and T2 in power amplifier circuit 91. Here, this power loss is P3 - Pout3 + 3. P3 and Pout3 are the output power of output terminal T13p and output terminal T2, respectively.

[0091] Curve L14 shows the frequency variation of power loss between output terminals T13m and T2 in power amplifier circuit 91. Here, this power loss is P4 - Pout3 + 3. P4 is the output power of output terminal T13m. Furthermore, the units for P3, P4, and Pout3 are "dBm".

[0092] The higher the power loss value, the better the amplifier's output power is transferred to the output terminals. In power amplifier circuit 91, a power loss of approximately -0.7 dBm can be ensured at 1.7 GHz. However, at frequencies higher than 2.3 GHz, the power loss will be lower than -1.0 dBm.

[0093] In contrast, in the power amplifier circuit 111, power loss of approximately -1 dBm or more can be achieved in a wide frequency range of 1.7 GHz to 2.7 GHz.

[0094] [The effect of electromagnetic field coupling between windings 312 and 313]

[0095] Figure 11 This shows the power amplifier circuit 111 (reference). Figure 1 A figure showing an example of the simulation results for all losses in ). Additionally, in Figure 11 In the diagram, the horizontal axis shows the frequency in "GHz" and the vertical axis shows the total loss in "dBm".

[0096] like Figure 11 As shown, curve L21 illustrates the frequency variation of all losses between amplifiers 151p and 151m in power amplifier circuit 111 and output terminal 32. Here, the total losses are P1 + P2 - Poutl.

[0097] Figure 12 as well as Figure 13 These are figures illustrating simulation results of total losses in the power amplifier circuits of the second and third reference examples, respectively. Additionally, Figure 12 as well as Figure 13 The representation method and Figure 11 The same. The power amplifier circuit in the second reference example is from... Figure 2 The power amplifier circuit 91 shown is the circuit after removing the filter LPF46. The power amplifier circuit of the third reference example is... Figure 1 The circuit shown in the power amplifier circuit 111 after removing the electromagnetic field coupling between winding 312 and winding 313.

[0098] Figure 12 The curve L22 shown illustrates the frequency variation of all losses in the power amplifier circuit of the second reference example. Figure 13 Curve L23 shows the frequency variation of all losses in the power amplifier circuit of the third reference example.

[0099] The higher the total loss value, the better the amplifier's output power is transferred to the output terminals. See curve L22 (reference). Figure 12 As shown, in the power amplifier circuit of the second reference example, approximately -0.7 dBm of total loss can be ensured at 1.7 GHz. However, at frequencies higher than 2.4 GHz, the total loss is less than -1.0 dBm. This is because the balun in the power amplifier circuit of the second reference example is composed of a single-stage transformer, thus the frequency range in which impedance can be well matched by this balun is relatively narrow.

[0100] For example, curve L23 (refer to) Figure 13 As shown, in the power amplifier circuit of the third reference example, although a total loss of slightly less than about -0.7 dBm can be ensured at 1.7 GHz, the total loss drops sharply in the region with higher frequencies than 2.2 GHz. This is because the winding 313 and capacitor 332 in the power amplifier circuit of the third reference example function as low-pass filters, thus significantly reducing the total loss on the high-frequency side.

[0101] In contrast, in the power amplifier circuit 111, windings 313 and 312 are electromagnetically coupled. Therefore, windings 313 and capacitor 332 do not function as low-pass filters, but instead function to expand the frequency range where impedance can be well matched. Thus, as shown in curve L21 (refer to...) Figure 11 As shown in the diagram, in the power amplifier circuit 111, all losses of approximately -1 dBm or more can be achieved in a wide frequency range of 1.7 GHz to 2.7 GHz.

[0102] Furthermore, although the structure of the balun 101, which includes a transformer 301 formed by windings 311, 312, and 313, has been described, it is not limited thereto. The balun 101 may also be a structure that includes a coupling line formed by three transmission lines instead of a transformer 301.

[0103] Furthermore, while the electromagnetic field coupling structure of windings 311 and 312 in transformer 301 has been described, it is not a limitation. Transformer 301 could also have an electromagnetic field coupling structure between windings 311 and 313, or between windings 311 and both windings 312 and 313. By incorporating such a transformer into a balun, impedance matching can be well achieved over a wide frequency range.

[0104] In addition, the balun 101 can also be used as an interstage matched balun by being positioned between the amplifier and the differential amplifier in the drive stage.

[0105] Furthermore, by being positioned between the input terminal and the differential amplifier, the balun 101 can also be used as an input-matched balun for the differential amplifier.

[0106] [Layout of Balanced-Unbalanced Converter 101]

[0107] The layout of the balun 101 will be described. Alternatively, the layout of a balun including coupling lines can also be implemented using the same layout as the balun 101. In the accompanying drawings, the x-axis, y-axis, and z-axis are sometimes shown. 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 is sometimes referred to as the z-axis + side, and the direction opposite to the arrow is sometimes referred to as the z-axis - side; the same applies to the other axes. Additionally, the z-axis + side and z-axis - side are sometimes referred to as the "upper side" and "lower side," respectively. Here, the direction of clockwise rotation when viewing the lower side from the upper side is defined as the clockwise direction cw. Furthermore, the direction of counterclockwise rotation when viewing the lower side from the upper side is defined as the counterclockwise direction ccw.

[0108] Figure 14 This is a schematic diagram illustrating the layout of the balanced-to-unbalanced converter 101. (See diagram for example.) Figure 14 As shown, semiconductor device 1 includes, for example, four wiring layers: 211, 212, 213, and 214. Wiring layers 211, 212, 213, and 214 are arranged sequentially from top to bottom. Alternatively, semiconductor device 1 may also have a structure containing three or fewer wiring layers or five or more wiring layers.

[0109] Wiring layers 211, 212, 213, and 214 each have a surface 211a (first surface), a surface 212a (third surface), a surface 213a (fourth surface), and a surface 214a (second surface). Surfaces 211a, 212a, 213a, and 214a each intersect an axis 201 parallel to the z-axis. In this embodiment, surfaces 211a, 212a, 213a, and 214a are each orthogonal to axis 201. Alternatively, the structure could be such that, for example, due to manufacturing variations, surfaces 211a, 212a, 213a, and 214a of each wiring layer are no longer parallel to the xy-plane, but are approximately parallel to the xy-plane, i.e., approximately orthogonal to axis 201.

[0110] In the wiring layer 211, on surface 211a, the winding 311 is formed by a metal wiring 701 (first conductive member) wound around the axis 201. In this embodiment, when viewed from above along a direction perpendicular to surface 214a (hereinafter, sometimes simply referred to as "viewed from above 214a"; the same applies to other surfaces), the metal wiring 701 is formed in a C-shape with the x-axis side open. The metal wiring 701 has a first end connected to the balance line 501p and a second end connected to the balance line 501m. The metal wiring 701 is wound clockwise in a direction cw for more than 3 / 4 of a turn but less than 1 turn along a circumference centered on the axis 201, from the first end to the second end.

[0111] Although not shown, amplifiers 151p and 151m are positioned on the opposite side of the metal wiring 701, for example, on surface 211a, sandwiching balanced lines 501p and 501m. This configuration allows for easy connection of amplifiers 151p and 151m to the metal wiring 701.

[0112] In the wiring layer 214, on surface 214a, the winding 312 is formed by a metal wiring 702 (second conductive member) wound around the shaft 201. In this embodiment, when viewed from above on surface 214a, the metal wiring 702 is formed in a C-shape with the x-axis + side open.

[0113] Metal wiring 702 has a grounded first end and a second end connected to an interlayer via 723. Metal wiring 702 is wound counterclockwise (ccw) from the first end to the second end along a circumference centered on axis 201, for more than 3 / 4 of a turn but less than 1 turn. The outer and inner diameters of metal wiring 702 are approximately the same as those of metal wiring 701.

[0114] The winding 313 is formed by a metal wire 703 (the third conductive member) wound around the shaft 201 in the opposite direction to the winding direction of the metal wire 702. The number of turns of the metal wire 703 is greater than the number of turns of the metal wire 702. In this embodiment, the metal wire 703 is wound around the shaft 201 for more than one and a half turns but less than two turns.

[0115] Here, the phrase "the winding direction of metal wiring 702 and the winding direction of metal wiring 703 are opposite" means that when direct current flows through metal wiring 702 and 703, the direction of the direct current flowing through metal wiring 702 is opposite to that flowing through metal wiring 703. Furthermore, the phrase "the winding direction of metal wiring 702 and the winding direction of metal wiring 703 are the same" means that when direct current flows through metal wiring 702 and 703, the direction of the direct current flowing through metal wiring 702 is the same as that flowing through metal wiring 703.

[0116] Specifically, the metal wiring 703 includes metal wiring 703a (part 1) and metal wiring 703b (part 2). Metal wiring 703a is formed on surface 212a in wiring layer 212. In this embodiment, when viewed from above on surface 212a, metal wiring 703a is formed in a C-shape with the x-axis + side open.

[0117] Metal wiring 703a has a first end connected to interlayer via 733 and a second end connected to the first end of output terminal 32 and capacitor 332 via unbalanced line 601. Metal wiring 703a is wound clockwise (cw) from the first end to the second end along a circumference centered on axis 201, for more than 3 / 4 of a turn but less than 1 turn. The outer and inner diameters of metal wiring 703a are approximately the same as the outer and inner diameters of metal wiring 701, respectively.

[0118] Metallic wiring 703b is formed on surface 213a in wiring layer 213. In this embodiment, when viewed from above on surface 213a, metallic wiring 703b is formed in a C-shape with the x-axis + side open.

[0119] Metal wiring 703b has a first end connected to the second end of metal wiring 702 via interlayer via 723 and grounded via capacitor 331, and a second end connected to the first end of metal wiring 703a via interlayer via 733. Metal wiring 703b is wound clockwise (cw) from the first end to the second end along a circumference centered on axis 201, for more than 3 / 4 of a turn but less than 1 turn. The outer and inner diameters of metal wiring 703b are approximately the same as those of metal wiring 701.

[0120] When viewed from above (along a direction perpendicular to surface 211a), metal wiring 701, metal wiring 702, metal wiring 703a, and metal wiring 703b overlap each other at least partially. Specifically, when viewed from above (alongside 211a), the area of ​​the overlapping portion of metal wiring 701 and metal wiring 702, 703a, or 703b (hereinafter, sometimes referred to as the first overlap area) is 50% or more of the area of ​​metal wiring 701. Preferably, the first overlap area is 60% or more of the area of ​​metal wiring 701. In this embodiment, the first overlap area is 75% or more of the area of ​​metal wiring 701.

[0121] By arranging the metal wirings 701, 702, 703a, and 703b and the interlayer vias 723 and 733 as described above, the area of ​​the configuration windings 311, 312, and 313 when viewed from above can be reduced. That is, a wide-bandwidth balun 101 can be compactly formed.

[0122] Furthermore, although the structure in which wiring layers 211, 212, 213, and 214 are arranged sequentially from top to bottom has been described, it is not limited to this. The order in which wiring layers 211, 212, 213, and 214 are arranged is not limited to this order and can be interchanged. Even if the order of wiring layers 211, 212, 213, and 214 are interchanged, a wide-bandwidth balanced-to-unbalanced converter 101 can still be compactly formed.

[0123] Furthermore, although the structure in which the entire winding 311 is formed on surface 211a has been described, it is not limited to this. It is also possible for a portion of the winding 311 to be formed on surface 211a and the other portions of the winding 311 to be formed on other surfaces.

[0124] Furthermore, although the structure in which the entire winding 312 is formed on surface 214a has been described, it is not limited to this. It is also possible for a portion of the winding 312 to be formed on surface 214a and the other portions of the winding 312 to be formed on other surfaces.

[0125] [Layout of Balanced-Unbalanced Converter 101A]

[0126] As Figure 14 The first modified example of the balanced-unbalanced converter 101, the balanced-unbalanced converter 101A shown, will be described. Figure 15 This is a schematic diagram showing the layout of the balun 101A. (See diagram for example.) Figure 15 As shown, the difference between the balun 101A and the balun 101 is that the winding 313 is formed by metal wiring disposed on one surface.

[0127] In this modified example, the semiconductor device 1 includes, for example, three wiring layers: 211, 212, and 214. The wiring layers 211, 212, and 214 are arranged sequentially from top to bottom. Alternatively, the semiconductor device 1 may also have a structure containing four or more wiring layers.

[0128] The outer diameter of the metal wiring 702 is smaller than the inner diameter of the metal wiring 701. In addition, the second end of the metal wiring 702 is connected to the interlayer via 723 and to the first end of the capacitor 331.

[0129] Metal wiring 7031 (third conductive member) is formed on surface 212a of wiring layer 212. Metal wiring 7031 includes metal wiring 703a (first part) and metal wiring 703c (second part). When viewed from above on the opposite side 212a, metal wiring 703c is formed in a C-shape with the x-axis + side open.

[0130] Metal wiring 703c has a first end and a second end connected to the second end of metal wiring 702 via an interlayer via 723. Metal wiring 703c is wound clockwise (cw) from the first end to the second end along a circumference centered on axis 201, for more than 3 / 4 of a turn but less than 1 turn. The outer and inner diameters of metal wiring 703c are approximately the same as those of metal wiring 702.

[0131] Metal wiring 703a has with Figure 14 The metal wiring 703a in the balun 101 shown has the same structure. The first end of metal wiring 703a is connected to the second end of metal wiring 703c. Metal wiring 703a is wound clockwise (cw) for more than 3 / 4 of a turn but less than 1 turn around the outside of metal wiring 703c along a circumference centered on axis 201, from the first end to the second end. The outer and inner diameters of metal wiring 703a are approximately the same as those of metal wiring 701.

[0132] When viewed from above opposite side 211a, metal wiring 701 and metal wiring 703a partially overlap each other. Specifically, when viewed from above opposite side 211a, the area of ​​the overlapping portion of metal wiring 701 and metal wiring 703a (hereinafter, sometimes referred to as the second overlap area) is 50% or more of the area of ​​metal wiring 701. Preferably, the second overlap area is 60% or more of the area of ​​metal wiring 701. In this embodiment, the second overlap area is 75% or more of the area of ​​metal wiring 701.

[0133] Furthermore, when viewed from above opposite side 211a, metal wiring 702 and metal wiring 703c partially overlap each other. Specifically, when viewed from above opposite side 211a, the area of ​​the overlapping portion of metal wiring 702 and metal wiring 703c (hereinafter, sometimes referred to as the third overlap area) is 50% or more of the area of ​​metal wiring 702. Preferably, the third overlap area is 60% or more of the area of ​​metal wiring 702. In this embodiment, the third overlap area is 75% or more of the area of ​​metal wiring 702.

[0134] By laying out the metal wirings 701, 702, 703a, and 703c and the interlayer vias 723 as described above, it is possible to achieve the same functionality as the balun 101 (see reference 101) with fewer wiring layers than the balun 101. Figure 14 The same electrical characteristics are used in the balanced-unbalanced converter 101A.

[0135] Furthermore, although the structure in which wiring layers 211, 212, and 214 are arranged sequentially from top to bottom has been described, it is not a limitation. The order in which wiring layers 211, 212, and 214 are arranged is not limited to this order and can be interchanged.

[0136] [Layout of Balanced-Unbalanced Converter 101B]

[0137] As Figure 14 The second variation of the balance-unbalance converter 101 shown, the balance-unbalance converter 101B, will be described. Figure 16 This is a schematic diagram showing the layout of the balun 101B. (See diagram for example.) Figure 16 As shown, the difference between the balun 101B and the balun 101 is that a portion of the windings 312 and 313 are formed by metal wiring disposed on one surface.

[0138] In this modified example, the semiconductor device 1 includes, for example, three wiring layers: 211, 212, and 214. The wiring layers 211, 212, and 214 are arranged sequentially from top to bottom. Alternatively, the semiconductor device 1 may also have a structure containing four or more wiring layers.

[0139] The outer diameter of the metal wiring 702 is smaller than the inner diameter of the metal wiring 701. Furthermore, the second terminal of the metal wiring 702 is connected to the first terminal of the capacitor 331.

[0140] The winding 313 is formed by a metal wire 7032 that is wound around the shaft 201 for more than one and a half turns but less than two turns throughout the wiring layers 212 and 214. Specifically, the metal wire 7032 includes a metal wire 703a (first part) formed on the surface 212a and a metal wire 703d (second part) formed on the surface 214a.

[0141] Viewed from above (opposite 214a), the metal wiring 703d is formed in a C-shape with the x-axis + side open, on the outer side of the metal wiring 702. The metal wiring 703d has a first end connected to the second end of the metal wiring 702, and a second end connected to the interlayer via 733. From the first end to the second end, the metal wiring 703d is wound clockwise (cw) more than 3 / 4 turn but less than 1 turn along a circumference centered on axis 201. The outer and inner diameters of the metal wiring 703d are approximately the same as those of the metal wiring 701.

[0142] On surface 212a of wiring layer 212, and Figure 14 The balun 101 shown is similarly provided with metal wiring 703a. The outer diameter and inner diameter of the metal wiring 703a are approximately the same as the outer diameter and inner diameter of the metal wiring 701, respectively.

[0143] When viewed from above opposite side 211a, metal wiring 701, metal wiring 703a, and metal wiring 703d partially overlap each other. Specifically, when viewed from above opposite side 211a, the area of ​​the overlapping portion of metal wiring 701 and metal wiring 703a or 703d (hereinafter, sometimes referred to as the fourth overlap area) is 50% or more of the area of ​​metal wiring 701. Preferably, the fourth overlap area is 60% or more of the area of ​​metal wiring 701. In this embodiment, the fourth overlap area is 75% or more of the area of ​​metal wiring 701.

[0144] By laying out the metal wirings 701, 702, 703a, and 703d and the interlayer vias 733 as described above, it is possible to enable the balance-to-unbalance converter 101 (see reference) to achieve the desired balance. Figure 14 To achieve the same level of performance as the balun 101 (see reference 101), fewer wiring layers are used. Figure 14 The same electrical characteristics are used in the balanced-unbalanced converter 101B.

[0145] Furthermore, although the structure in which wiring layers 211, 212, and 214 are arranged sequentially from top to bottom has been described, it is not a limitation. The order in which wiring layers 211, 212, and 214 are arranged is not limited to this order and can be interchanged.

[0146] [Layout of Balanced-Unbalanced Converter 101C]

[0147] As Figure 14 The third variation of the balanced-unbalanced converter 101 shown, the balanced-unbalanced converter 101C, will be described. Figure 17 This is a schematic diagram illustrating the layout of the balun 101C. (See diagram for example.) Figure 17 As shown, the difference between the balun 101C and the balun 101 is that the windings 312 and 313 are formed by metal wiring disposed on one surface.

[0148] In this modified example, the semiconductor device 1 includes, for example, two wiring layers 211 and 214. Wiring layers 211 and 214 are arranged sequentially from top to bottom. Alternatively, the semiconductor device 1 may also have a structure containing three or more wiring layers.

[0149] On surface 211a of wiring layer 211, and Figure 14 The balun 101 shown is similarly provided with metal wiring 701. On surface 214a of wiring layer 214, and... Figure 14 The balun 101 shown is similarly equipped with metal wiring 702.

[0150] In this modified example, the outer and inner diameters of the metal wiring 702 are approximately the same as those of the metal wiring 701. Furthermore, the second terminal of the metal wiring 702 is connected to the first terminal of the capacitor 331. Alternatively, the outer diameter of the metal wiring 702 may be different from that of the metal wiring 701. Furthermore, the inner diameter of the metal wiring 702 may be different from that of the metal wiring 701.

[0151] On the outer side of the metal wiring 702 on surface 214a, the winding 313 is formed by metal wiring 7033 wound around shaft 201 for more than one and a half turns but less than two turns. In detail, metal wiring 7033 includes metal wiring 703e (first part) and metal wiring 703f (second part).

[0152] When viewed from above on the opposite side 214a, the metal wiring 703f is formed in a C-shape with the x-axis + side open on the outside of the metal wiring 702. The metal wiring 703f has a first end and a second end connected to the second end of the metal wiring 702. From the first end to the second end, the metal wiring 703f is wound clockwise (cw) more than 3 / 4 turn but less than 1 turn along a circumference centered on axis 201.

[0153] Viewed from above on the opposite side 214a, the metal wiring 703e, outside the metal wiring 703f, is formed in a C-shape with the x-axis + side open. The metal wiring 703e has a first end connected to the second end of the metal wiring 703f, and a second end connected to the first end of the output terminal 32 and the capacitor 332 via the unbalanced line 601. From the first end to the second end, the metal wiring 703e is wound clockwise (cw) more than 3 / 4 turn but less than 1 turn along a circumference centered on axis 201.

[0154] When viewed from above opposite side 211a, metal wiring 701 and metal wiring 702 partially overlap each other. Specifically, when viewed from above opposite side 211a, the area of ​​the overlapping portion of metal wiring 701 and metal wiring 702 (hereinafter, sometimes referred to as the fifth overlap area) is 50% or more of the area of ​​metal wiring 701. Preferably, the fifth overlap area is 60% or more of the area of ​​metal wiring 701. In this embodiment, the fifth overlap area is 75% or more of the area of ​​metal wiring 701.

[0155] By laying out the metal wiring 701, 702, 703e, and 703f as described above, it is possible to achieve a balance-to-unbalance converter 101B (see reference). Figure 16 To achieve the same level of performance as the balun 101 (see reference 101), fewer wiring layers are used. Figure 14 The same electrical characteristics are used in the balanced-unbalanced converter 101C.

[0156] [Second Implementation]

[0157] The power amplifier circuit 115 according to the second embodiment will be described. Figure 18 This is the circuit diagram of power amplifier circuit 115. (For example...) Figure 18 As shown, the power amplifier circuit 115 according to the second embodiment differs from the power amplifier circuit 111 according to the first embodiment in that the number of transformer stages is increased.

[0158] Power amplifier circuit 115 and Figure 1 Compared to the power amplifier circuit 111 shown, a balun 103 is provided instead of a balun 101, and a capacitor 335 is also included. The balun 103 and... Figure 1 Compared to the balun 101 shown, the transformer 302 and capacitor 334 (third capacitor) are also included. The transformer 302 includes winding 314 (fourth wiring) and winding 315 (fifth wiring).

[0159] The winding 314 is disposed between the second end of the winding 313 and the unbalanced line 601, and has a first end connected to the second end of the winding 313 and a second end connected to the unbalanced line 601.

[0160] The winding 315 has a first end connected to the second end of the winding 314, and a second end that is grounded and coupled to the electromagnetic field of the winding 314.

[0161] Capacitor 334 has a first terminal connected to the second terminal of winding 314 and a second terminal grounded. Capacitor 335 is disposed on unbalanced line 601 and has a first terminal connected to the second terminal of winding 314 and a second terminal connected to output terminal 32.

[0162] In this way, by further configuring the structure of transformer 302 after transformer 301, and... Figure 1 Compared to the balun 101 shown, it can expand the frequency range where impedance can be well matched.

[0163] Furthermore, although the structure of the balun 103 including windings for electromagnetic field coupling has been described, it is not limited thereto. The balun 103 may also be a transmission line that includes electromagnetic field coupling instead of windings.

[0164] [Layout of Balanced-Unbalanced Converter 103]

[0165] The layout of the balun 103 will be described. Furthermore, in the balun 103, the layout of the balun, where a transmission line is provided instead of a winding, can also be implemented using the same layout as the balun 103.

[0166] Figure 19 This is a schematic diagram showing the layout of the balanced-to-unbalanced converter 103. (See diagram for example.) Figure 19 As shown, semiconductor device 1 includes, for example, five wiring layers: 211, 212, 213, 214, and 215. Wiring layers 211, 215, 212, 213, and 214 are arranged sequentially from top to bottom. Alternatively, semiconductor device 1 may also have a structure containing six or more wiring layers.

[0167] Wiring layers 211, 215, 212, 213, and 214 each have a surface 211a (first surface), a surface 215a (fifth surface), a surface 212a (fourth surface), a surface 213a (third surface), and a surface 214a (second surface), respectively. Surfaces 211a, 212a, 213a, 214a, and 215a each intersect an axis 201 parallel to the z-axis. In this embodiment, surfaces 211a, 215a, 212a, 213a, and 214a are each orthogonal to axis 201.

[0168] On the surface 211a of wiring layer 211 and the surface 214a of wiring layer 214, and Figure 14 The balun 101 shown is similarly provided with metal wiring 701 and 702 respectively.

[0169] A metal wiring 7034 (third conductive member) is formed on surface 213a of wiring layer 213. In this embodiment, when viewed from above surface 213a, the metal wiring 7034 is formed in a C-shape with the x-axis + side open. The metal wiring 7034 has a first end connected to the second end of metal wiring 702 via interlayer via 723 and grounded via capacitor 331, and a second end connected to interlayer via 734. The metal wiring 7034 is wound clockwise (cw) from the first end to the second end along a circumference centered on axis 201, for more than 3 / 4 turn but less than 1 turn. The outer diameter and inner diameter of the metal wiring 7034 are approximately the same as the outer diameter and inner diameter of the metal wiring 701, respectively.

[0170] In the wiring layer 212, on surface 212a, the winding 314 is formed by a metal wire 704 (the fourth conductive member) wound around the axis 201 in the opposite direction to the winding direction of the metal wire 702. In this embodiment, when viewed from above on surface 212a, the metal wire 704 is formed in a C-shape with the x-axis + side open.

[0171] Metal wiring 704 has a first end connected to a second end of metal wiring 7034 via interlayer via 734 and grounded via capacitor 332, and a second end connected to an interlayer via 745 and connected to the first end of capacitor 334 and the first end of capacitor 335 via unbalanced line 601. Metal wiring 704 is wound clockwise (cw) from the first end to the second end along a circumference centered on axis 201, for more than 3 / 4 of a turn but less than 1 turn. The outer and inner diameters of metal wiring 704 are approximately the same as the outer and inner diameters of metal wiring 701, respectively.

[0172] In the wiring layer 215, on surface 215a, the winding 315 is formed by a metal wire 705 (the fifth conductive member) wound around the axis 201 in the winding direction of the metal wire 702. In this embodiment, when viewed from above on surface 215a, the metal wire 705 is formed in a C-shape with the x-axis + side open.

[0173] Metal wiring 705 has a first end connected to the second end of metal wiring 704 via an interlayer via 745, and a grounded second end. Metal wiring 705 is wound counterclockwise (ccw) for more than 3 / 4 of a turn but less than 1 turn from the first end to the second end along a circumference centered on axis 201. The outer and inner diameters of metal wiring 705 are approximately the same as those of metal wiring 701.

[0174] When viewed from above opposite side 211a, metal wiring 701, metal wiring 702, metal wiring 7034, metal wiring 704, and metal wiring 705 partially overlap each other. Specifically, when viewed from above opposite side 211a, the area of ​​the overlapping portion of metal wiring 701 and metal wiring 702, 7034, 704, or 705 (hereinafter, sometimes referred to as the sixth overlap area) is 50% or more of the area of ​​metal wiring 701. Preferably, the sixth overlap area is 60% or more of the area of ​​metal wiring 701. In this embodiment, the sixth overlap area is 75% or more of the area of ​​metal wiring 701.

[0175] By arranging the metal wirings 701, 702, 7034, 704, and 705 and the interlayer vias 723, 734, and 745 as described above, the area of ​​the windings 311, 312, 313, 314, and 315 when viewed from above can be reduced. That is, a wider bandwidth balun 103 can be compactly formed.

[0176] Furthermore, although the structure in which wiring layers 211, 215, 212, 213, and 214 are arranged sequentially from top to bottom has been described, it is not limited to this. The order in which wiring layers 211, 215, 212, 213, and 214 are arranged is not limited to this order and can be interchanged.

[0177] Furthermore, although the structure in which the entire winding 313 is formed on surface 213a has been described, it is not limited to this. It is also possible for a portion of the winding 313 to be formed on surface 213a and the other portions of the winding 313 to be formed on other surfaces.

[0178] Furthermore, although the structure in which the entire winding 314 is formed on surface 212a has been described, it is not limited to this. It is also possible for a portion of the winding 314 to be formed on surface 212a and the other portions of the winding 314 to be formed on other surfaces.

[0179] Furthermore, although the structure in which the entire winding 315 is formed on surface 215a has been described, it is not limited to this. It is also possible for a portion of the winding 315 to be formed on surface 215a and the other portions of the winding 315 to be formed on other surfaces.

[0180] The exemplary embodiments of the present invention have been described above. In the balun 101, the first wiring has a first terminal connected to a balun 501p that transmits a balun signal, and a second terminal connected to a balun 501m that transmits the same balun signal. The second wiring has a grounded first terminal and a grounded second terminal. The third wiring has a first terminal connected to the second terminal of the second wiring, and a second terminal connected to an unbalanced line 601 that transmits an unbalanced signal, and is electromagnetically coupled to the second wiring. The capacitor 331 has a first terminal connected to the first terminal of the third wiring, and a grounded second terminal. The capacitor 332 has a first terminal connected to the second terminal of the third wiring, and a grounded second terminal. Furthermore, the first wiring is electromagnetically coupled to at least one of the second and third wirings.

[0181] In this way, by using electromagnetic field coupling through the second and third wirings and electromagnetic field coupling through at least one of the first, second, and third wirings, a balun with the same characteristics as a balun using a two-stage transformer or coupling lines can be realized. That is, conversion between balanced and unbalanced signals can be performed through at least one of the first, second, and third wirings, and an impedance transformation circuit can be implemented. Furthermore, compared to the conventional power amplifier circuit 91 (see reference...),... Figure 2 In contrast, by replacing the LPF46 filter with the second and third wirings and capacitor 332, the impedance variation with respect to the fundamental frequency of the radio signal and the decrease in power loss can be suppressed over a wider frequency band. Therefore, a balanced-to-unbalanced converter that can well match the impedance between the preceding and following stages can be provided.

[0182] Furthermore, in the balun 101, 101A, 101B, 101C, or 103, the first wiring is formed by a metal wiring 701 wound around the shaft 201. The second wiring is formed by a metal wiring 702 wound around the shaft 201. The third wiring is formed by metal wiring 703, 7031, 7032, 7033, or 7034 wound around the shaft 201 in the opposite direction to the winding direction of the metal wiring 702.

[0183] In this way, the structure formed by the first wiring, the second wiring and the third wiring, which are each metal wiring wound around a common axis 201, enables the formation of balanced-unbalanced converters 101, 101A, 101B, 101C and 103 with a small area occupied on the substrate surface while ensuring electromagnetic field coupling between the wirings.

[0184] Furthermore, in the balun 101, 101A, 101B or 101C, the number of turns of the metal wiring 703, 7031, 7032 or 7033 is greater than the number of turns of the metal wiring 702.

[0185] With this structure, even when the impedance of the circuit on the third wiring side is high, the impedance between the circuit on the first wiring side and the circuit on the third wiring side can be well matched.

[0186] Furthermore, in the balun 101, 101A, or 101B, a metal wiring 701 is formed on a surface 211a intersecting the axis 201. A metal wiring 702 is formed on a surface 214a intersecting the axis 201. A metal wiring 703a, which is included in the metal wiring 703, 7031, or 7032, is formed on a surface 212a intersecting the axis 201.

[0187] In this way, by forming metal wirings 701, 702, and 703a on surfaces 211a, 214a, and 212a respectively, the first wiring and a portion of the second and third wirings can be formed by three wiring layers. As a result, the thickness of the substrate on which the baluns 101, 101A, and 101B are installed can be reduced.

[0188] Furthermore, in the balanced-unbalanced converter 101, a metal wire 703b, which is included in the metal wire 703 and is different from the metal wire 703a, is formed on the surface 213a that intersects the axis 201.

[0189] With this structure, a balanced-to-unbalanced converter 101 can be formed from four wiring layers, thus enabling a compact balanced-to-unbalanced converter 101.

[0190] Furthermore, in the balun 101, when viewed from above 211a, the metal wiring 701, metal wiring 702, metal wiring 703a and metal wiring 703b overlap each other at least partially.

[0191] With this structure, when viewed from above 211a, the area occupied by the balun 101 can be suppressed while ensuring electromagnetic field coupling between the first wiring and the second or third wiring, as well as electromagnetic field coupling between the second wiring and the third wiring.

[0192] Furthermore, in the balun 101A, a metal wire 703c, which is included in the metal wire 7031 and is different from the metal wire 703a, is formed on the surface 212a.

[0193] With this structure, a balun 101A can be formed from three wiring layers, thus enabling a more compact balun 101A than the balun 101. Furthermore, compared to the case where the number of windings of the metal wiring 703 is formed in multiple wiring layers, a balun with smaller parasitic capacitance between the metal wirings can be achieved.

[0194] Furthermore, in the balun 101A, when viewed from above 211a, the metal wiring 701 and the metal wiring 703a partially overlap each other.

[0195] With this structure, when viewed from above 211a, the area occupied by the balun 101A can be suppressed.

[0196] Furthermore, in the balun 101A, when viewed from above 211a, the metal wiring 702 and the metal wiring 703c partially overlap each other.

[0197] With this structure, when viewed from above 211a, the area occupied by the balun 101A can be suppressed while ensuring sufficient electromagnetic field coupling between the second and third wiring.

[0198] Furthermore, in the balun 101B, a metal wire 703d, which is included in the metal wire 7032 and is different from the metal wire 703a, is formed on the surface 214a.

[0199] With this structure, a balun 101B can be formed from three wiring layers, thus enabling a more compact balun 101B than the balun 101.

[0200] Furthermore, in the balun 101B, when viewed from above 211a, the metal wiring 701, metal wiring 703a, and metal wiring 703d partially overlap each other.

[0201] With this structure, when viewed from above 211a, the area occupied by the balun 101B can be suppressed.

[0202] Furthermore, in the balun 101C, metal wiring 701 is formed on the surface 211a intersecting the axis 201. Metal wiring 702 and 7033 are formed on the surface 214a intersecting the axis 201.

[0203] With this structure, a balun 101C can be formed from two wiring layers, thus enabling a more compact balun 101C than the baluns 101, 101A, and 101B.

[0204] Furthermore, in the balun 101C, when viewed from above 211a, the metal wiring 701 and the metal wiring 702 partially overlap each other.

[0205] With this structure, when viewed from above 211a, the area occupied by the balun 101C can be suppressed while ensuring sufficient electromagnetic field coupling between the first wiring and the second wiring.

[0206] Furthermore, in the balun 103, a fourth wiring is disposed between the second end of the third wiring and the unbalanced line 601, having a first end connected to the second end of the third wiring and a second end connected to the unbalanced line 601. A fifth wiring has a first end connected to the second end of the fourth wiring and a grounded second end, and is electromagnetically coupled to the fourth wiring. A capacitor 334 has a first end connected to the second end of the fourth wiring and a grounded second end.

[0207] In this way, by including a fourth and fifth wiring for electromagnetic field coupling, a balun with the same characteristics as a balun using a three-stage transformer or coupling line can be achieved. That is, compared to the balun 101, by further configuring the fourth and fifth wiring and the capacitor 335, impedance variations with respect to the fundamental frequency of the radio frequency signal can be suppressed over a wider frequency band.

[0208] Furthermore, in the balun 103, the first wiring is formed by a metal wire 701 wound around the shaft 201. The second wiring is formed by a metal wire 702 wound around the shaft 201. The third wiring is formed by a metal wire 7034 wound around the shaft 201 in the opposite direction to the winding direction of the metal wire 702. The fourth wiring is formed by a metal wire 704 wound around the shaft 201 in the opposite direction. The fifth wiring is formed by a metal wire 705 wound around the shaft 201 in the winding direction.

[0209] In this way, the structure formed by the first, second, third, fourth and fifth wirings, which are each metal wiring wound around a common axis 201, enables the formation of a balanced-unbalanced converter 103 with a small area occupied on the substrate surface while ensuring electromagnetic field coupling between wirings.

[0210] Furthermore, in the balanced-unbalanced converter 103, metal wiring 701, 702, 7034, 704 and 705 are formed on surfaces 211a, 214a, 213a, 212a and 215a that intersect with axis 201, respectively.

[0211] With this structure, the first wiring, the second wiring, the third wiring, the fourth wiring and the fifth wiring can be formed by five wiring layers, thus reducing the thickness of the substrate on which the balun 103 is installed.

[0212] Furthermore, in the balun 103, when viewed from above 211a, metal wiring 701, metal wiring 702, metal wiring 7034, metal wiring 704 and metal wiring 705 partially overlap each other.

[0213] With this structure, when viewed from above 211a, it is possible to suppress the area occupied by the balun 103 while fully ensuring electromagnetic field coupling between the first wiring and the second or third wiring, electromagnetic field coupling between the second wiring and the third wiring, and electromagnetic field coupling between the fourth wiring and the fifth wiring.

[0214] Furthermore, in the balun 101, the first wiring, the second wiring, and the third wiring are transmission lines.

[0215] This structure allows for the easy formation of coupling lines while ensuring sufficient electromagnetic field coupling within the frequency band of wireless signals.

[0216] Furthermore, in the balun 101, the first wiring, the second wiring, and the third wiring are respectively windings 311, 312, and 313.

[0217] In this way, the structure formed by the windings of the first, second and third wirings, which can each ensure a large inductance, can fully ensure the electromagnetic field coupling between the first wiring and the second or third wiring, as well as the electromagnetic field coupling between the second wiring and the third wiring.

[0218] Furthermore, the embodiments described above are for the purpose of facilitating understanding of the present invention and are not intended to limit or interpret the present invention. The present invention can be modified / improved without departing from its spirit, and its equivalents are also included in the present invention. That is, any product resulting from appropriate design modifications to the embodiments by those skilled in the art, as long as it possesses the features of the present invention, is 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 examples shown and can be appropriately modified. Moreover, each embodiment is exemplified; it is self-evident that partial substitutions or combinations of the structures shown in different embodiments are possible, and such substitutions or combinations, as long as they contain the features of the present invention, are also included within the scope of the present invention.

Claims

1. A balanced-to-unbalanced converter, comprising: The first wiring has a first end connected to a first balanced line of one of the balanced signals and a second end connected to a second balanced line of the other of the balanced signals. The second wiring has a first end and a second end, wherein the first end is grounded; The third wiring has a first end connected to the second end of the second wiring and a second end connected to the unbalanced line transmitting the unbalanced signal, and is coupled to the electromagnetic field of the second wiring. The first capacitor has a first terminal connected to the first terminal of the third wiring and a second terminal that is grounded; as well as The second capacitor has a first terminal connected to the second terminal of the third wiring and a second terminal that is grounded. The first wiring is electromagnetically coupled to at least one of the second and third wirings.

2. The balun-to-unbalance converter according to claim 1, wherein, The first wiring is formed by a first conductive member wound around an axis. The second wiring is formed by a second conductive member wound around the axis. The third wiring is formed by a third conductive member wound around the axis in the opposite direction to the winding direction of the second conductive member.

3. The balanced-to-unbalanced converter according to claim 2, wherein, The number of windings of the third conductive member is greater than the number of windings of the second conductive member.

4. The balanced-to-unbalanced converter according to claim 2 or 3, wherein, At least a portion of the first conductive member is formed on a first surface intersecting the axis. At least a portion of the second conductive member is formed on a second surface intersecting the axis. The first portion contained in the third conductive member is formed on the third surface intersecting the axis.

5. The balun-to-unbalance converter according to claim 4, wherein, A second portion, which is included in the third conductive member and is different from the first portion, is formed on a fourth surface that intersects the axis.

6. The balun-to-unbalance converter according to claim 5, wherein, When the first surface is viewed from above in a direction perpendicular to it, the first conductive member, the second conductive member, the first portion, and the second portion overlap each other at least partially.

7. The balun-to-unbalance converter according to claim 4, wherein, A second portion, which is included in the third conductive member and is different from the first portion, is formed on the third surface.

8. The balun-to-unbalance converter according to claim 7, wherein, When viewed from above along a direction perpendicular to the first surface, the first conductive member and the first portion partially overlap each other.

9. The balun-to-unbalance converter according to claim 7 or 8, wherein, When viewed from above along a direction perpendicular to the first surface, the second conductive member and the second portion partially overlap each other.

10. The balun-to-unbalance converter according to claim 4, wherein, A second portion, which is included in the third conductive member and is different from the first portion, is formed on the second surface.

11. The balun of claim 10, wherein, When viewed from above along a direction perpendicular to the first surface, the first conductive member, the first portion, and the second portion partially overlap each other.

12. The balun-to-unbalance converter according to claim 2 or 3, wherein, At least a portion of the first conductive member is formed on a first surface intersecting the axis. The second conductive member and the third conductive member are formed on a second surface that intersects the axis.

13. The balun-to-unbalance converter according to claim 12, wherein, When the first surface is viewed from above in a direction perpendicular to the first surface, the first conductive member and the second conductive member partially overlap each other.

14. The balun-to-unbalance converter according to claim 1 or 2, wherein, It also has: The fourth wiring is disposed between the second end of the third wiring and the unbalanced line, and has a first end connected to the second end of the third wiring and a second end connected to the unbalanced line; The fifth wiring has a first end connected to the second end of the fourth wiring and a grounded second end, and is electromagnetically coupled to the fourth wiring; as well as The third capacitor has a first terminal connected to the second terminal of the fourth wiring and a second terminal that is grounded.

15. The balun of claim 14, wherein, The first wiring is formed by a first conductive member wound around an axis. The second wiring is formed by a second conductive member wound around the axis. The third wiring is formed by a third conductive member wound around the axis in the opposite direction to the winding direction of the second conductive member. The fourth wiring is formed by a fourth conductive member wound around the axis in the opposite direction. The fifth wiring is formed by a fifth conductive member wound around the winding direction along the axis.

16. The balun of claim 15, wherein, At least a portion of the first conductive member, at least a portion of the second conductive member, at least a portion of the third conductive member, at least a portion of the fourth conductive member, and at least a portion of the fifth conductive member are respectively formed on the first, second, third, fourth, and fifth surfaces intersecting the axis.

17. The balun of claim 16, wherein, When the first surface is viewed from above in a direction perpendicular to the first surface, the first conductive member, the second conductive member, the third conductive member, the fourth conductive member, and the fifth conductive member partially overlap each other.

18. The balun-to-unbalance converter according to any one of claims 1 to 13, wherein, The first wiring, the second wiring, and the third wiring are each transmission lines.

19. The balun-to-unbalance converter according to any one of claims 1 to 13, wherein, The first wiring, the second wiring, and the third wiring are each windings.

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