Low noise amplifier circuit

Abstract

The present application provides a low noise amplifier circuit, which can realize wideband. The low noise amplifier circuit (1) comprises: an input terminal (101) and an output terminal (102); an amplifier (10) connected between the input terminal (101) and the output terminal (102); a transmission line transformer (20) comprising inductors (21) and (22) connected between the input terminal (101) and the input end of the amplifier (10); and an inductor (23) connected between the ground connection end of the amplifier (10) and the ground, one end of the inductor (21) and one end of the inductor (22) are connected with the input terminal (101), the other end of the inductor (21) is connected with the input end of the amplifier (10), the other end of the inductor (22) is connected with the ground, and the coupling coefficient (k23) of the inductor (22) and the inductor (23) is larger than the coupling coefficient (k13) of the inductor (21) and the inductor (23).

Description

Technical Field

[0001] This invention relates to low-noise amplifier circuits. Background Technology

[0002] Patent Document 1 discloses a low-noise amplifier circuit comprising: a common-source amplifier; a first inductor connected between an input terminal and the gate terminal of the common-source amplifier; and a second inductor connected to the source terminal of the common-source amplifier. By magnetically coupling the first inductor and the second inductor, the linearity of the low-noise amplifier circuit can be improved.

[0003] Patent Document 1: U.S. Patent Application Publication No. 2017 / 0194918.

[0004] However, in the aforementioned prior art, the first inductor and the second inductor are coupled by magnetic fields, so that the first inductor and the second inductor function as low-pass filters. However, the amplification characteristics on the high-frequency side deteriorate, and the bandwidth cannot be widened. Summary of the Invention

[0005] Therefore, the present invention provides a low-noise amplifier circuit capable of achieving wide bandwidth.

[0006] One aspect of the present invention relates to a low-noise amplifier circuit comprising: an input terminal and an output terminal; an amplifier connected between the input terminal and the output terminal; a transmission line transformer including a first inductor and a second inductor connected between the input terminal and the input terminal of the amplifier; and a third inductor connected between the ground connection terminal of the amplifier and ground, wherein one end of the first inductor and one end of the second inductor are connected to the input terminal, the other end of the first inductor is connected to the input terminal of the amplifier, the other end of the second inductor is connected to ground, and the coupling coefficient between the second inductor and the third inductor is greater than the coupling coefficient between the first inductor and the third inductor.

[0007] Additionally, one embodiment of the present invention relates to a low-noise amplifier circuit comprising: a substrate; an input terminal and an output terminal; an amplifier connected between the input terminal and the output terminal; a transmission line transformer including a first inductor and a second inductor connected between the input terminal and the input terminal of the amplifier; and a third inductor connected between the ground connection terminal of the amplifier and ground. One end of the first inductor and one end of the second inductor are connected to the input terminal, the other end of the first inductor is connected to the input terminal of the amplifier, and the other end of the second inductor is connected to ground. The first inductor is formed by a first wiring disposed on the substrate, the second inductor is formed by a spiral second wiring disposed on the substrate, and the third inductor is formed by a third wiring disposed on the substrate. One of the first wiring and the third wiring is disposed in the inner region of the second wiring from a top view of the substrate, and the other of the first wiring and the third wiring is disposed in the outer region of the second wiring from a top view of the substrate.

[0008] Additionally, one embodiment of the present invention relates to a low-noise amplifier circuit comprising: a substrate; an input terminal and an output terminal; an amplifier connected between the input terminal and the output terminal; a transmission line transformer including a first inductor and a second inductor connected between the input terminal and the input terminal of the amplifier; and a third inductor connected between the ground connection terminal of the amplifier and ground. One end of the first inductor and one end of the second inductor are connected to the input terminal, the other end of the first inductor is connected to the input terminal of the amplifier, and the other end of the second inductor is connected to ground. The first inductor, the second inductor, and the third inductor are formed by wiring disposed on the substrate, and the distance between the second inductor and the third inductor is smaller than the distance between the first inductor and the third inductor.

[0009] According to one aspect of the present invention, a low-noise amplifier circuit can be widened. Attached Figure Description

[0010] Figure 1 This is a circuit diagram of the low-noise amplifier circuit involved in the implementation method.

[0011] Figure 2 This is a circuit diagram of the low-noise amplifier circuit involved in the modified example 1 of the implementation method.

[0012] Figure 3A This is a top view of the low-noise amplifier circuit involved in the implementation method.

[0013] Figure 3B This is a cross-sectional view of the low-noise amplifier circuit involved in the implementation method.

[0014] Figure 4 This is a top view of the low-noise amplifier circuit involved in Variation 2 of the implementation method.

[0015] Figure 5 This is a top view of the low-noise amplifier circuit involved in Variation 3 of the implementation method.

[0016] Figure 6 This is a top view of the low-noise amplifier circuit involved in Variation 4 of the implementation method.

[0017] Figure 7 This is a top view of the low-noise amplifier circuit involved in variation 5 of the implementation method.

[0018] Figure 8A This is a top view of the low-noise amplifier circuit according to Variation 6 of the implementation method.

[0019] Figure 8B This is a cross-sectional view of the low-noise amplifier circuit according to Variation 6 of the implementation method.

[0020] Explanation of reference numerals in the attached figures

[0021] 1, 1A, 1B, 1C, 1D, 1E, 1F... Low-noise amplifier circuit; 10... Amplifier; 11, 12... FET; 20... Transmission line transformer; 21, 22, 23, 24... Inductors; 31, 32, 33, 34, 35... Capacitors; 41, 42... Resistors; 90... Substrate; 90a, 90b... Main surface; 101... Input terminal; 102... Output terminal; 103, 104... Bias terminal; D1, D2... Drain terminal; D13, D23... Distance; G1, G2... Gate terminal; k12, k13, k23... Coupling coefficient; n1, n2... Node; S1, S2... Source terminal. Detailed Implementation

[0022] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, the embodiments described below are either general or specific examples. The numerical values, shapes, materials, constituent elements, arrangements of constituent elements, and connection methods shown in the following embodiments are examples and are not intended to limit the present invention.

[0023] Furthermore, the figures are schematic diagrams that have been appropriately emphasized, omitted, or proportionally adjusted for the purpose of illustrating the invention, and are not necessarily strictly illustrative, sometimes differing from the actual shapes, positional relationships, and proportions. In the figures, substantially identical components are sometimes labeled with the same reference numerals, and repetitive descriptions are omitted or simplified.

[0024] In the following figures, the x-axis and y-axis are mutually orthogonal axes on a plane parallel to the main surface of the substrate. The z-axis is perpendicular to the main surface of the substrate, with its positive direction representing the upward direction and its negative direction representing the downward direction.

[0025] In the following description, “connection” includes not only direct connection using connection terminals and / or wiring conductors, but also electrical connection via other circuit elements.

[0026] "C connected between A and B" means that one end of C is connected to A, and the other end of C is connected to B, indicating that C is connected in series in the path connecting A and B. "C connected between the path connecting A and B and ground" means that one end of C is connected to the path connecting A and B, and the other end of C is connected to ground, indicating that C is connected in parallel in the path connecting A and B. "The path connecting A and B" refers to a path formed by conductors electrically connecting A and B.

[0027] A "terminal" indicates the point where a conductor within a circuit element ends. Furthermore, when the impedance between conductors in a circuit element is sufficiently low, a terminal can be interpreted not only as a single point, but also as any point on the conductor between the circuit elements or the entire conductor. A "node" indicates a point between circuit elements. Furthermore, when the impedance between conductors in a circuit element is sufficiently low, a node can be interpreted not only as a single point, but also as any point on the conductor between the circuit elements or the entire conductor.

[0028] "Wiring disposed on a substrate" includes wiring disposed on the main surface of the substrate and wiring disposed within the substrate. "Wiring disposed on the main surface of the substrate" includes, in addition to the case where the wiring is in contact with the main surface of the substrate, the case where the wiring is disposed above the main surface without contacting it (e.g., the wiring is stacked on top of other components that are in contact with the main surface). Furthermore, "wiring disposed on the main surface of the substrate" may also include wiring disposed in a recess formed on the main surface. "Wiring disposed within the substrate" includes, in addition to the case where the wiring is encapsulated within the substrate, the case where the entire wiring is disposed between the two main surfaces of the substrate but a portion of the wiring is not covered by the substrate, and the case where only a portion of the wiring is disposed within the substrate.

[0029] "Top view of the substrate" means observing an object by projecting it orthogonally onto the xy plane in the negative z-axis direction. "Overlap of A and B in the top view of the substrate" means that the region of A projected orthogonally onto the xy plane overlaps with the region of B projected orthogonally onto the xy plane.

[0030] "A and B are directly connected" means that A and B are physically in contact and connected. Furthermore, "A and B are directly connected" also includes A being connected to B via a bonding material. "Bonding material" refers to the substance sandwiched between A and B for the physical connection (bonding) between them.

[0031] Terms like "parallel" and "perpendicular" indicate the relationship between elements; terms like "straight line" indicate the shape of elements; and numerical ranges do not only mean strict but also imply substantially equal ranges, such as including a few percent of error.

[0032] (Implementation Method)

[0033] [Circuit configuration of low-noise amplifier circuit 1]

[0034] Figure 1 This is a circuit diagram of the low-noise amplifier circuit 1 according to the embodiment. Furthermore, Figure 1 This is an illustrative circuit diagram. The low-noise amplifier circuit 1 can be installed using a variety of circuit mounting methods and techniques. Therefore, the following description of the low-noise amplifier circuit 1 should not be interpreted in a limited way.

[0035] The low-noise amplifier circuit 1 includes an input terminal 101 and an output terminal 102, bias terminals 103 and 104, an amplifier 10, a transmission line transformer 20, inductors 23 and 24, capacitors 31, 32, 33 and 34, and resistors 41 and 42.

[0036] Input terminal 101 is an external connection terminal of the low-noise amplifier circuit 1, used to receive high-frequency signals. Input terminal 101 is connected externally to an antenna (not shown) of the low-noise amplifier circuit 1, and internally to a capacitor 31.

[0037] Output terminal 102 is an external connection terminal of the low-noise amplifier circuit 1, used to supply high-frequency signals. Output terminal 102 is connected externally to, for example, an RFIC (Radio Frequency Integrated Circuit) (not shown) of the low-noise amplifier circuit 1, and internally to a capacitor 32.

[0038] Amplifier 10 can amplify high-frequency signals using a power supply voltage VDD supplied from a power source (not shown). Amplifier 10 is connected between input terminal 101 and output terminal 102. Specifically, the input terminal of amplifier 10 is connected to input terminal 101 via capacitor 31 and transmission line transformer 20. The output terminal of amplifier 10 is connected to output terminal 102 via capacitor 32, and is also connected to the power supply via inductor 24. The ground connection terminal of amplifier 10 is connected to ground via inductor 23.

[0039] Amplifier 10 includes cascaded FETs 11 and 12. FET 11 is an example of a first FET, having a gate terminal G1, a drain terminal D1, and a source terminal S1. The gate terminal G1 is the input terminal of amplifier 10, and the source terminal S1 is the ground connection terminal of amplifier 10. The drain terminal D1 is connected to the source terminal S2 of FET 12. FET 12 is an example of a second FET, having a gate terminal G2, a drain terminal D2, and a source terminal S2. The gate terminal G2 is connected to the bias terminal 104 via resistor 42 and to ground via capacitor 34. The drain terminal D2 is the output terminal of amplifier 10.

[0040] FET11 and 12 are, for example, field-effect transistors (FETs), and more specifically, MOSFETs (Metal Oxide Semiconductor Field-Effect Transistors). Furthermore, FET11 and 12 are not limited to field-effect transistors. FET11 and 12 can also be bipolar transistors.

[0041] Inductor 23 is an example of a third inductor, a so-called source inductor, connected between the ground connection terminal of amplifier 10 and ground. The inductance value of inductor 23 is, for example, 0.1nH to 1nH.

[0042] Inductor 24 is a so-called choke inductor, connected between the power supply and FET 12.

[0043] The transmission line transformer 20 includes inductors 21 and 22, which are connected between input terminal 101 and the input terminal of amplifier 10. The transmission line transformer 20 uses electromagnetic field coupling between inductors 21 and 22 to achieve phase shift and impedance transformation.

[0044] Inductor 21 is an example of a first inductor and is part of the main circuit of the so-called transmission line transformer 20. Inductor 22 is an example of a second inductor and is part of the secondary circuit of the so-called transmission line transformer 20. Inductors 21 and 22 are configured to magnetically couple with each other. One end of inductor 21 and one end of inductor 22 are connected at node n1 and connected to input terminal 101 via capacitor 31. The other end of inductor 21 is connected to the input terminal of amplifier 10. The other end of inductor 22 is connected to ground via capacitor 33 and, at node n2, is connected to bias terminal 103 via resistor 41. The inductance values ​​of inductors 21 and 22 are, for example, 1nH to 10nH.

[0045] The low-noise amplifier circuit 1 is capable of amplifying high-frequency signals in the WLAN 7GHz band (WiFi 7GHz band, registered trademark). In this case, the inductance value of inductor 21 is, for example, 1.1nH, the inductance value of inductor 22 is, for example, 1.6nH, and the inductance value of inductor 23 is, for example, 0.2nH.

[0046] Capacitor 31 is an example of a first capacitor, connected between input terminal 101 and one end of inductor 21. Capacitor 31 is a so-called coupling capacitor, which allows high-frequency components to pass through and blocks DC components in the path connecting input terminal 101 and amplifier 10.

[0047] Capacitor 33 is an example of a second capacitor, connected between the other end of inductor 22 and between bias terminal 103 and ground. Capacitor 33 is capable of interrupting the DC component in the path connecting inductor 22 to ground.

[0048] Capacitor 34 is connected between the gate terminal G2 of FET12 and ground. Capacitor 32 is connected between the path connecting FET12 and inductor 24 and the output terminal 102.

[0049] In the low-noise amplifier circuit 1 with the above-described circuit configuration, the coupling coefficient k23, which represents the degree of magnetic coupling between inductor 22 and inductor 23, is larger than the coupling coefficient k13, which represents the degree of magnetic coupling between inductor 21 and inductor 23.

[0050] Through magnetic field coupling between inductors 22 and 23, the high-frequency signal input to amplifier 10 is fed back from inductor 23 to inductor 22, forming a high-pass filter in the signal transmission path between inductors 22 and 23. Therefore, the amplification characteristics of the low-noise amplifier circuit 1 can be widened.

[0051] On the other hand, if inductor 21 and inductor 23 are magnetically coupled, the high-frequency signal input to amplifier 10 is fed back from inductor 23 to inductor 21. However, an equivalent series resistor is inserted in the signal transmission path between inductors 21 and 23, forming a low-pass filter. Therefore, the amplification characteristics on the high-frequency side deteriorate, making widebanding impossible.

[0052] According to the low-noise amplifier circuit 1 of this embodiment, since the coupling coefficient k13 is smaller than the coupling coefficient k23, the formation of a low-pass filter between inductor 23 and inductor 21 is suppressed. Furthermore, since the coupling coefficient k23 is larger than the coupling coefficient k13, good linearity is ensured at high frequencies through the feedback loop between inductor 23 and inductor 22. Therefore, the amplification characteristics of the low-noise amplifier circuit 1 can be widened.

[0053] Furthermore, the coupling coefficient k12, which preferably represents the degree of magnetic coupling between inductor 21 and inductor 22, is larger than the coupling coefficient k23 between inductor 22 and inductor 23. This ensures a greater degree of freedom in phase shift and impedance transformation within the transmission line transformer 20.

[0054] Furthermore, inductors 24, capacitors 31-34, resistors 41 and 42, and bias terminals 103 and 104 may also be excluded from the low-noise amplifier circuit 1.

[0055] Furthermore, amplifier 10 is not limited to a source-grounded amplifier. For example, amplifier 10 could also be a gate-grounded amplifier.

[0056] Alternatively, amplifier 10 may not include cascaded FETs 11 and 12. For example, amplifier 10 may include FET 11 but not FET 12. In this case, FET 11 is an example of a first FET, with its gate terminal being the input terminal of amplifier 10, its source terminal being the ground connection terminal of amplifier 10, and its drain terminal being the output terminal of amplifier 10. Furthermore, bias terminal 104, resistor 42, and capacitor 34 are not configured.

[0057] Additionally, in the circuit configuration of amplifier 10, it is also possible to... Figure 1 Other circuit elements and wiring can be inserted between the disclosed circuit elements and signal path connections. For example, a capacitor can be connected between the drain terminal D2 and the gate terminal G2 of FET12.

[0058] [Circuit configuration of the low-noise amplifier circuit 1A involved in Variation 1]

[0059] Figure 2 This is a circuit diagram of the low-noise amplifier circuit 1A according to Embodiment 1. As shown in the diagram, the low-noise amplifier circuit 1A according to this embodiment includes an input terminal 101 and an output terminal 102, bias terminals 103 and 104, an amplifier 10, a transmission line transformer 20, inductors 23 and 24, capacitors 32, 34 and 35, and resistors 41 and 42. Compared with the low-noise amplifier circuit 1 according to Embodiment 1, the low-noise amplifier circuit 1A according to this embodiment differs in the configuration of supplying the bias voltage to the FET 11. Therefore, in the following description, the configurations of the low-noise amplifier circuit 1A according to this embodiment that are the same as those of the low-noise amplifier circuit 1 according to Embodiment 1 will be omitted, and the description will focus on the bias voltage supply configuration that is different from that of the low-noise amplifier circuit 1A according to Embodiment 1.

[0060] Input terminal 101 is connected externally to an antenna (not shown) in the low-noise amplifier circuit 1A, for example, or internally to a transmission line transformer 20 in the low-noise amplifier circuit 1A.

[0061] The input terminal of amplifier 10 is connected to input terminal 101 via capacitor 35 and transmission line transformer 20, and is also connected to bias terminal 103 via resistor 41.

[0062] One end of inductor 21 and one end of inductor 22 are connected to input terminal 101. The other end of inductor 21 is connected to the input terminal of amplifier 10 via capacitor 35. The other end of inductor 22 is connected to ground.

[0063] Capacitor 35 is an example of a first capacitor, connected between the other end of inductor 21 and the input terminal of amplifier 10. Capacitor 35 is a so-called coupling capacitor, which allows high-frequency components to pass through and blocks DC components in the path connecting input terminal 101 and amplifier 10.

[0064] In the low-noise amplifier circuit 1A with the above-described circuit configuration, the coupling coefficient k23 between inductor 22 and inductor 23 is larger than the coupling coefficient k13 between inductor 21 and inductor 23.

[0065] Therefore, since the coupling coefficient k13 is smaller than the coupling coefficient k23, the formation of a low-pass filter between inductor 23 and inductor 21 can be suppressed. Furthermore, since the coupling coefficient k23 is larger than the coupling coefficient k13, a high-pass filter is formed between inductor 23 and inductor 22. Thus, through the feedback loop formed by the magnetic field coupling of inductors 23 and 22, good linearity is ensured up to the high-frequency side, thereby widening the amplification characteristics of the low-noise amplifier circuit 1A.

[0066] Furthermore, by acquiring the inductance value of each inductor, the magnetic flux direction of the inductor, the distance between the two inductors, and the material properties of the surrounding areas of the two inductors, the coupling coefficient of the two inductors in this embodiment and its variations can be determined. For example, when the two inductors are configured by wiring disposed on the substrate 90, the arrangement of the two inductors disposed on the substrate 90, the material properties of the two inductors and the substrate 90 can be used as input parameters to perform calculations using an electromagnetic field simulator.

[0067] [3. Mounting examples of inductors 21, 22, and 23 according to the embodiments]

[0068] Next, while referring to Figure 3A as well as Figure 3B An example of mounting the inductors 21 to 23 in the low-noise amplifier circuit 1 will be described. Figure 3A This is a top view of the low-noise amplifier circuit 1 according to the embodiment. Figure 3B This is a cross-sectional view of the low-noise amplifier circuit 1 according to the embodiment. Specifically, Figure 3A This is a top view (perspective) of the substrate 90 from the z-axis, showing the area where inductors 21-23 are formed. Figure 3B yes Figure 3A A cross-sectional view at line IIIb-IIIb.

[0069] also, Figure 3A as well as Figure 3B The illustrations of inductors 21, 22, and 23 show configurations that inductors 21 to 23 can be installed using a variety of circuit mounting methods and any of the circuit techniques employed. Therefore, the descriptions of inductors 21 to 23 provided below should not be interpreted in a limited way.

[0070] like Figure 3A as well as Figure 3B As shown, the low-noise amplifier circuit 1, in addition to having Figure 1 In addition to the circuit configuration shown, it also includes a substrate 90.

[0071] The substrate 90 is, for example, a substrate made of semiconductor material, and is sometimes referred to as a mold or chip. As a semiconductor material, silicon single crystal, gallium nitride (GaN), or silicon carbide (SiC) can be used.

[0072] Alternatively, the substrate 90 may be, for example, a substrate made of low-temperature co-fired ceramics formed by simultaneously firing multiple dielectric layers, or a substrate made of high-temperature co-fired ceramics, a component-embedded substrate, a substrate having a redistribution layer (RDL), or a printed circuit board, etc.

[0073] like Figure 3A As shown, inductor 21 is formed by a spiral first wiring disposed on substrate 90. Inductor 22 is formed by a spiral second wiring disposed on substrate 90. Inductor 23 is formed by a third wiring disposed on substrate 90. Furthermore, as... Figure 3B As shown, inductors 21 to 23 are formed on the same layer of substrate 90.

[0074] Specifically, inductor 21 is formed by a first wiring extending in a right-hand spiral from the outside to the inside. Inductor 22 is formed by a second wiring extending in a left-hand spiral from the inside to the outside. One end of inductor 21 and one end of inductor 22 are connected at node n1. The other end of inductor 21 is connected to the gate terminal G1 of FET 11 via a connection wiring. The other end of inductor 22 is connected to node n2. One end of inductor 23 is connected to the source terminal S1 of FET 11. The other end of inductor 23 is connected to ground.

[0075] Here, as Figure 3A as well as Figure 3B As shown, the first wiring constituting inductor 21 is disposed in the inner region of the second wiring constituting inductor 22, and the third wiring constituting inductor 23 is disposed in the outer region of the second wiring.

[0076] Therefore, from a top view of the substrate 90, inductors 21 and 23 are arranged with inductor 22 sandwiched between them, thus allowing the coupling coefficient k23 between inductors 22 and 23 to be larger than the coupling coefficient k13 between inductors 21 and 23. This suppresses the formation of a low-pass filter between inductors 23 and 21. Furthermore, the feedback loop formed by the magnetic field coupling between inductors 23 and 22 ensures good linearity up to the high-frequency side. Consequently, the amplification characteristics of the low-noise amplifier circuit 1 can be widened.

[0077] Furthermore, the coupling coefficient k12, which preferably represents the degree of magnetic coupling between inductor 21 and inductor 22, is larger than the coupling coefficient k23 between inductor 22 and inductor 23. This ensures a greater degree of freedom in phase shift and impedance transformation within the transmission line transformer 20.

[0078] Furthermore, each of the inductors 21 to 23 may not be composed of wiring formed only on one layer of the substrate 90, but may be composed of multiple wirings formed on multiple layers of the substrate 90.

[0079] Alternatively, the first wiring, the second wiring, and the third wiring may not be formed on the same layer of the substrate 90, but preferably at least a portion of each of the first wiring, the second wiring, and the third wiring is formed on the same layer of the substrate 90.

[0080] In addition, the first wiring may not be spiral, and the third wiring may also be spiral.

[0081] In addition, the winding direction of inductors 21 and 22 is not limited to the above-mentioned winding direction.

[0082] In addition, in the low-noise amplifier circuit 1 according to this embodiment, it can be configured such that the first wiring constituting the inductor 21 is disposed in the outer region of the second wiring constituting the inductor 22, and the third wiring constituting the inductor 23 is disposed in the inner region of the second wiring.

[0083] Therefore, from the top view of the substrate 90, inductors 21 and 23 are arranged with inductor 22 sandwiched between them, so the coupling coefficient k23 between inductors 22 and 23 can be made larger than the coupling coefficient k13 between inductors 21 and 23. As a result, the amplification characteristics of the low-noise amplifier circuit 1 can be widened.

[0084] In addition, inductors 21 and 23 can be surface-mount chip inductors disposed on substrate 90.

[0085] Furthermore, in this embodiment, the first wiring constituting inductor 21, the second wiring constituting inductor 22, and the third wiring constituting inductor 23 (hereinafter referred to as wiring constituting the inductor) are each defined as follows. Wiring constituting the inductor is defined as a section of wiring having a certain linewidth and a certain film thickness in a top view of the substrate 90, sandwiched between a conductive path or a terminal. However, in the case where the inductor is composed of multiple wirings spread across multiple layers, the diameter of the conductive path connecting the wirings of different layers may differ from the linewidth and film thickness of the wiring within the layer; this conductive path is also included in the wiring constituting the inductor.

[0086] [4. Mounting examples of inductors 21, 22, and 23 as described in Variation 2]

[0087] Next, while referring to Figure 4 The installation example of inductors 21 to 23 in the low-noise amplifier circuit 1B involved in Modification Example 2 will be described. Figure 4 This is a top view of the low-noise amplifier circuit 1B according to Variation 2 of the implementation method. Specifically, Figure 4 This is a view of the area where inductors 21 to 23 are formed on the substrate 90 from the z-axis positive side (perspective).

[0088] The low-noise amplifier circuit 1B involved in Modification Example 2 has Figure 1 The circuit configuration shown differs from the low-noise amplifier circuit 1 described in the embodiment only in the arrangement of inductors 21 to 23. Therefore, in the following description, the configuration identical to that of the low-noise amplifier circuit 1B described in this variation will be omitted, and the description will focus on the arrangement of inductors 21 to 23, which differ from that of the low-noise amplifier circuit 1 described in the embodiment.

[0089] like Figure 4 As shown, the low-noise amplifier circuit 1B, in addition to having Figure 1 In addition to the circuit configuration shown, it also includes a substrate 90.

[0090] like Figure 4 As shown, inductor 21 is formed by a spiral first wiring disposed on substrate 90. Inductor 22 is formed by a spiral second wiring disposed on substrate 90. Inductor 23 is formed by a spiral third wiring disposed on substrate 90. Inductors 21 to 23 are formed on the same layer of substrate 90.

[0091] Specifically, inductor 21 is formed by a first wiring extending in a right-hand spiral from the outside to the inside. Inductor 22 is formed by a second wiring extending in a left-hand spiral from the inside to the outside. One end of inductor 21 and one end of inductor 22 are connected at node n1. The other end of inductor 21 is connected to the gate terminal G1 of FET 11. The other end of inductor 22 is connected to node n2 via a connection wiring. Inductor 23 is formed by a third wiring extending in a right-hand spiral from the outside to the inside. One end of inductor 23 is connected to the source terminal S1 of FET 11 via a connection wiring. The other end of inductor 23 is connected to ground via a connection wiring.

[0092] Here, from a top view of the substrate 90, the winding shafts of inductor 21 and inductor 23, extending in the z-axis direction, are contained within the inner region of the second wiring. Furthermore, the first wiring constituting inductor 21 is disposed outside the outer region of the second wiring constituting inductor 22, and the third wiring constituting inductor 23 is disposed inside the second wiring.

[0093] Therefore, from a top view of the substrate 90, inductors 21 and 23 are arranged to sandwich inductor 22. Furthermore, the area ratio of the inner region of inductor 23 to the inner region of inductor 21 is smaller than the area ratio of the inner region of inductor 23 to the inner region of inductor 22. This allows the coupling coefficient k23 between inductors 22 and 23 to be larger than the coupling coefficient k13 between inductors 21 and 23. This suppresses the formation of a low-pass filter between inductors 23 and 21. Additionally, the feedback loop formed by the magnetic field coupling between inductors 23 and 22 ensures good linearity up to the high-frequency side. This widens the amplification characteristics of the low-noise amplifier circuit 1B.

[0094] Furthermore, each of the inductors 21 to 23 may not be composed of wiring formed only on one layer of the substrate 90, but may be composed of multiple wirings formed on multiple layers of the substrate 90.

[0095] Alternatively, the first wiring, the second wiring, and the third wiring may not be formed on the same layer of the substrate 90, but preferably at least a portion of each of the first wiring, the second wiring, and the third wiring is formed on the same layer of the substrate 90.

[0096] In addition, the winding direction of inductors 21 to 23 is not limited to the above-mentioned winding direction.

[0097] Alternatively, in the low-noise amplifier circuit 1B involved in this modified example, it may be configured such that the first wiring constituting the inductor 21 is disposed in the inner region of the second wiring constituting the inductor 22, and the third wiring constituting the inductor 23 is disposed in the outer region of the second wiring.

[0098] Therefore, from a top view of the substrate 90, inductors 21 and 23 are arranged to sandwich inductor 22. Furthermore, the area ratio of the inner region of inductor 21 to the inner region of inductor 23 is smaller than that of inductor 22 to the inner region of inductor 23. This allows the coupling coefficient k23 between inductors 22 and 23 to be larger than the coupling coefficient k13 between inductors 21 and 23. Consequently, the amplification characteristics of the low-noise amplifier circuit 1B can be widened.

[0099] [5. Mounting examples of inductors 21, 22, and 23 as described in Variation 3]

[0100] Next, while referring to Figure 5 The installation example of inductors 21 to 23 in the low-noise amplifier circuit 1C involved in Modification Example 3 will be described. Figure 5 This is a top view of the low-noise amplifier circuit 1C according to Variation 3 of the implementation method. Specifically, Figure 5 This is a view of the area where inductors 21 to 23 are formed on the substrate 90 from the z-axis positive side (perspective).

[0101] The low-noise amplifier circuit 1C involved in Modification Example 3 has Figure 1 The circuit configuration shown differs from the low-noise amplifier circuit 1 described in the embodiment only in the arrangement of inductors 21 to 23. Therefore, in the following description of the low-noise amplifier circuit 1C described in this variation, the configuration identical to that of the low-noise amplifier circuit 1 described in the embodiment will be omitted, and the description will focus on the arrangement of inductors 21 to 23, which differ from that of the low-noise amplifier circuit 1 described in the embodiment.

[0102] like Figure 5 As shown, the low-noise amplifier circuit 1C, in addition to having Figure 1 The circuit configuration shown also includes a substrate 90.

[0103] like Figure 5As shown, inductor 21 is formed by a spiral first wiring disposed on substrate 90. Inductor 22 is formed by a spiral second wiring disposed on substrate 90. Inductor 23 is formed by a spiral third wiring disposed on substrate 90. Inductors 21 to 23 are formed on the same layer of substrate 90.

[0104] Specifically, inductor 21 is formed by a first wiring extending in a left-hand spiral from the outside to the inside. Inductor 22 is formed by a second wiring extending in a right-hand spiral from the outside to the inside. One end of inductor 21 and one end of inductor 22 are connected at node n1. The other end of inductor 21 is connected to the gate terminal G1 of FET 11 via a connection wiring. The other end of inductor 22 is connected to node n2 via a connection wiring. Inductor 23 is formed by a third wiring extending in a right-hand spiral from the outside to the inside. One end of inductor 23 is connected to the source terminal S1 of FET 11 via a connection wiring. The other end of inductor 23 is connected to ground via a connection wiring.

[0105] Here, from a top view of the substrate 90, the winding axis of the inductor 21 extending in the z-axis direction is included in the outer region of the second wiring. Furthermore, the winding axis of the inductor 23 extending in the z-axis direction is included in the inner region of the second wiring. Additionally, the first wiring constituting the inductor 21 is disposed in the outer region of the second wiring constituting the inductor 22, and the third wiring constituting the inductor 23 is disposed in the inner region of the second wiring.

[0106] Therefore, from a top view of the substrate 90, inductors 21 and 23 are arranged with inductor 22 sandwiched between them, thus allowing the coupling coefficient k23 between inductors 22 and 23 to be larger than the coupling coefficient k13 between inductors 21 and 23. This suppresses the formation of a low-pass filter between inductors 23 and 21. Furthermore, the feedback loop formed by the magnetic field coupling between inductors 23 and 22 ensures good linearity up to the high-frequency side. Consequently, the amplification characteristics of the low-noise amplifier circuit 1C can be widened.

[0107] Furthermore, inductors 21 to 23 may be composed of wiring not only formed on one layer of substrate 90, but also of multiple wiring formed on multiple layers of substrate 90.

[0108] In addition, the first wiring, the second wiring and the third wiring may not be formed on the same layer of the substrate 90, but preferably at least a portion of the first wiring, the second wiring and the third wiring are formed on the same layer of the substrate 90.

[0109] In addition, the winding direction of inductors 21 to 23 is not limited to the above-mentioned winding direction.

[0110] Alternatively, inductors 21 and 23 can also be surface-mount chip inductors disposed on substrate 90.

[0111] [6. Mounting examples of inductors 21, 22, and 23 as described in Variation 4]

[0112] Next, while referring to Figure 6 The installation example of inductors 21 to 23 in the low-noise amplifier circuit 1D involved in Modification Example 4 will be described. Figure 6 This is a top view of the low-noise amplifier circuit 1D according to Variation 4 of the implementation method. Specifically, Figure 6 This is a view of the area where inductors 21 to 23 are formed on the substrate 90 from the z-axis positive side (perspective).

[0113] The low-noise amplifier circuit 1D involved in Modification Example 4 has Figure 1 The circuit configuration shown differs from the low-noise amplifier circuit 1 of the embodiment only in the arrangement of inductors 21 to 23. Furthermore, the low-noise amplifier circuit 1D of this modification differs from the low-noise amplifier circuit 1C of modification 3 only in the substitution of the arrangement of inductors 21 and 23 relative to inductor 22. Therefore, in the following description of the low-noise amplifier circuit 1D of this modification, the configuration identical to that of the low-noise amplifier circuit 1C of modification 3 will be omitted, and the description will focus on the configuration of inductors 21 to 23 that differ from those of the low-noise amplifier circuit 1C of modification 3.

[0114] like Figure 6 As shown, inductor 21 is formed by a first wiring extending in a right-hand spiral from the outside to the inside. Inductor 22 is formed by a second wiring extending in a left-hand spiral from the inside to the outside. One end of inductor 21 and one end of inductor 22 are connected at node n1 via a connecting wiring. The other end of inductor 21 is connected to the gate terminal G1 of FET 11 via a connecting wiring. The other end of inductor 22 is connected to node n2. Inductor 23 is formed by a third wiring extending in a right-hand spiral from the outside to the inside. One end of inductor 23 is connected to the source terminal S1 of FET 11. The other end of inductor 23 is connected to ground.

[0115] Here, from a top view of the substrate 90, the winding axis of the inductor 21 extending in the z-axis direction is included in the inner region of the second wiring. Furthermore, the winding axis of the inductor 23 extending in the z-axis direction is included in the outer region of the second wiring. Additionally, the first wiring constituting the inductor 21 is disposed in the inner region of the second wiring constituting the inductor 22, and the third wiring constituting the inductor 23 is disposed in the outer region of the second wiring.

[0116] Therefore, from the top view of the substrate 90, inductors 21 and 23 are arranged with inductor 22 sandwiched between them, thus allowing the coupling coefficient k23 between inductors 22 and 23 to be larger than the coupling coefficient k13 between inductors 21 and 23. This suppresses the formation of a low-pass filter between inductors 23 and 21. Furthermore, the feedback loop formed by the magnetic field coupling between inductors 23 and 22 ensures good linearity up to the high-frequency side. Consequently, the amplification characteristics of the low-noise amplifier circuit 1D can be widened.

[0117] Furthermore, inductors 21 to 23 may be composed of wiring not only formed on one layer of substrate 90, but also of multiple wiring formed on multiple layers of substrate 90.

[0118] In addition, the first wiring, the second wiring and the third wiring may not be formed on the same layer of the substrate 90, but preferably at least a portion of the first wiring, the second wiring and the third wiring are formed on the same layer of the substrate 90.

[0119] In addition, the winding direction of inductors 21 to 23 is not limited to the above-mentioned winding direction.

[0120] Alternatively, inductors 21 and 23 can also be surface-mount chip inductors disposed on substrate 90.

[0121] [7. Mounting examples of inductors 21, 22, and 23 as described in Variation 5]

[0122] Next, while referring to Figure 7 The installation example of inductors 21 to 23 in the low-noise amplifier circuit 1E involved in Modification Example 5 will be described. Figure 7 This is a top view of the low-noise amplifier circuit 1E according to Variation 5 of the implementation method. Specifically, Figure 7 This is a view of the area where inductors 21 to 23 are formed on the substrate 90 from the z-axis positive side (perspective).

[0123] The low-noise amplifier circuit 1E involved in Modification Example 5 has Figure 1 The circuit configuration shown differs from the low-noise amplifier circuit 1 described in the embodiment only in the arrangement of inductors 21 to 23. Therefore, in the following description of the low-noise amplifier circuit 1E described in this variation, the configuration identical to that of the low-noise amplifier circuit 1 described in the embodiment will be omitted, and the description will focus on the arrangement of inductors 21 to 23, which differ from that of the low-noise amplifier circuit 1 described in the embodiment.

[0124] like Figure 7 As shown, the low-noise amplifier circuit 1E, in addition to having Figure 1In addition to the circuit configuration shown, it also includes a substrate 90.

[0125] like Figure 7 As shown, inductor 21 is formed by a spiral first wiring disposed on substrate 90. Inductor 22 is formed by a spiral second wiring disposed on substrate 90. Inductor 23 is formed by a spiral third wiring disposed on substrate 90. Inductors 21 to 23 are formed on the same layer of substrate 90.

[0126] Specifically, inductor 21 is formed by a first wiring extending in a left-hand spiral from the outside to the inside. Inductor 22 is formed by a second wiring extending in a right-hand spiral from the outside to the inside. One end of inductor 21 and one end of inductor 22 are connected at node n1 via a connecting wiring. The other end of inductor 21 is connected to the gate terminal G1 of FET 11 via a connecting wiring. The other end of inductor 22 is connected to node n2 via a connecting wiring. Inductor 23 is formed by a third wiring extending in a right-hand spiral from the outside to the inside. One end of inductor 23 is connected to the source terminal S1 of FET 11. The other end of inductor 23 is connected to ground.

[0127] Here, the distance D23 between the second and third wirings is smaller than the distance D13 between the first and third wirings. In other words, the distance D23 between inductor 22 and inductor 23 is smaller than the distance D13 between inductor 21 and inductor 23.

[0128] Therefore, since the distance D23 is smaller than the distance D13, the coupling coefficient k23 between inductors 22 and 23 can be made larger than the coupling coefficient k13 between inductors 21 and 23. This suppresses the formation of a low-pass filter between inductors 23 and 21. Furthermore, good linearity is ensured at high frequencies through the feedback loop formed by the magnetic field coupling between inductors 23 and 22. Thus, the amplification characteristics of the low-noise amplifier circuit 1E can be widened.

[0129] Furthermore, inductors 21 to 23 may be composed of wiring not only formed on one layer of substrate 90, but also of multiple wiring formed on multiple layers of substrate 90.

[0130] In addition, the first wiring, the second wiring and the third wiring may not be formed on the same layer of the substrate 90, but preferably at least a portion of the first wiring, the second wiring and the third wiring are formed on the same layer of the substrate 90.

[0131] In addition, the winding direction of inductors 21 to 23 is not limited to the above-mentioned winding direction.

[0132] In addition, preferably, from a top view of the substrate 90, the winding shaft of one of the inductors 21 to 23 is not included in either of the inner regions of the wiring forming the other two inductors.

[0133] In addition, inductors 21 to 23 can be surface-mount chip inductors disposed on substrate 90.

[0134] [Modification 6: Installation examples of inductors 21, 22, and 23]

[0135] Next, while referring to Figure 8A as well as Figure 8B The installation example of inductors 21 to 23 in the low-noise amplifier circuit 1F involved in Modification Example 6 will be described. Figure 8A This is a top view of the low-noise amplifier circuit 1F according to Variation 6 of the implementation method. Figure 8B This is a cross-sectional view of the low-noise amplifier circuit 1F according to Variation 6 of the implementation method. Specifically, Figure 8A This is a top view (perspective) of the substrate 90 from the z-axis, showing the area where inductors 21-23 are formed. Figure 8B yes Figure 8A A cross-sectional view at line VIIIb-VIIIb. Furthermore, in Figure 8A In order to make it easier to understand the configuration relationship of inductors 21 to 23, the connection wiring and terminals connected to inductors 21 to 23 are not described.

[0136] The low-noise amplifier circuit 1F involved in Modification Example 6 has Figure 1 The circuit configuration shown differs from the low-noise amplifier circuit 1 described in the embodiment only in the arrangement of inductors 21 to 23. Therefore, in the following description of the low-noise amplifier circuit 1F described in this modified example, the configurations identical to those in the low-noise amplifier circuit 1 described in the embodiment will be omitted, and the description will focus on the configuration of inductors 21 to 23, which differ from those in the low-noise amplifier circuit 1 described in the embodiment.

[0137] like Figure 8A as well as Figure 8B As shown, the low-noise amplifier circuit 1F, in addition to having Figure 1 In addition to the circuit configuration shown, it also includes a substrate 90 having opposing main surfaces 90a (first main surface) and 90b (second main surface).

[0138] like Figure 8AAs shown, inductor 21 is formed by a spiral first wiring disposed on substrate 90. Inductor 22 is formed by a spiral second wiring disposed on substrate 90. Inductor 23 is formed by a spiral third wiring disposed on substrate 90. In a top (perspective) view of the main surface 90a, the winding axis of inductor 21 and the winding axis of inductor 23, extending in the z-axis direction, are contained within the inner peripheral region of the second wiring forming inductor 22.

[0139] Here, as Figure 8B As shown, the first wiring is disposed on the main surface 90a side of the second wiring, and the third wiring is disposed on the main surface 90b side of the second wiring. In other words, inductor 21 is disposed on the main surface 90a side of inductor 22, and inductor 23 is disposed on the main surface 90b side of inductor 22.

[0140] Therefore, the distance D23 between inductors 22 and 23 is smaller than the distance D13 between inductors 21 and 23, thus allowing the coupling coefficient k23 between inductors 22 and 23 to be larger than the coupling coefficient k13 between inductors 21 and 23. This suppresses the formation of a low-pass filter between inductors 23 and 21. Furthermore, the feedback loop formed by the magnetic field coupling between inductors 23 and 22 ensures good linearity up to the high-frequency side. Consequently, the amplification characteristics of the low-noise amplifier circuit 1F can be widened.

[0141] Furthermore, each of the inductors 21 to 23 may not be composed of wiring formed only on one layer of the substrate 90, but may be composed of multiple wirings formed on multiple layers of the substrate 90.

[0142] In addition, the winding direction of inductors 21 to 23 is not limited to the above-mentioned winding direction.

[0143] [9 effects, etc.]

[0144] As described above, the low-noise amplifier circuit 1 according to this embodiment includes: an input terminal 101 and an output terminal 102; an amplifier 10 connected between the input terminal 101 and the output terminal 102; a transmission line transformer 20 including inductors 21 and 22 connected between the input terminal 101 and the input terminal of the amplifier 10; and an inductor 23 connected between the ground connection terminal of the amplifier 10 and ground. One end of inductor 21 and one end of inductor 22 are connected to the input terminal 101, the other end of inductor 21 is connected to the input terminal of the amplifier 10, the other end of inductor 22 is connected to ground, and the coupling coefficient k23 between inductor 22 and inductor 23 is larger than the coupling coefficient k13 between inductor 21 and inductor 23.

[0145] Therefore, since the coupling coefficient k13 is smaller than the coupling coefficient k23, the formation of a low-pass filter between inductor 23 and inductor 21 is suppressed. Furthermore, since the coupling coefficient k23 is larger than the coupling coefficient k13, good linearity is ensured at high frequencies through the feedback loop between inductor 23 and inductor 22. Thus, the amplification characteristics of the low-noise amplifier circuit 1 can be widened.

[0146] Additionally, for example, the low-noise amplifier circuit 1, the low-noise amplifier circuit 1B according to the modified example 2, the low-noise amplifier circuit 1C according to the modified example 3, and the low-noise amplifier circuit 1D according to the modified example 4 also include a substrate 90, an inductor 21 formed by a first wiring disposed on the substrate 90, an inductor 22 formed by a spiral second wiring disposed on the substrate 90, and an inductor 23 formed by a third wiring disposed on the substrate 90. One of the first wiring and the third wiring is disposed in the inner region of the second wiring from a top view of the substrate 90, and the other of the first wiring and the third wiring is disposed in the outer region of the second wiring from a top view of the substrate 90.

[0147] Therefore, from the top view of the substrate 90, inductors 21 and 23 are arranged with inductor 22 sandwiched between them, thus making the coupling coefficient k23 between inductors 22 and 23 larger than the coupling coefficient k13 between inductors 21 and 23. This suppresses the formation of a low-pass filter between inductors 23 and 21. Furthermore, good linearity is ensured up to the high-frequency side by means of the feedback loop formed by the magnetic field coupling between inductors 23 and 22. Thus, the amplification characteristics of the low-noise amplifier circuit 1 (1B, 1C, 1D) can be widened.

[0148] Additionally, for example, in the low-noise amplifier circuit 1B, the first wiring and the third wiring are spiral-shaped, and from the top view of the substrate 90, the winding axis of the inductor 21 and the winding axis of the inductor 23 are contained in the inner region of the second wiring.

[0149] Therefore, from the top view of the substrate 90, since inductors 21 and 23 are arranged to sandwich inductor 22, the coupling coefficient k23 between inductors 22 and 23 can be made larger than the coupling coefficient k13 between inductors 21 and 23. As a result, the amplification characteristics of the low-noise amplifier circuit 1B can be widened.

[0150] Additionally, for example, the low-noise amplifier circuit 1E involved in Modification 5 also includes a substrate 90, inductors 21, 22 and 23 are formed by wiring disposed on the substrate 90, and the distance D23 between inductors 22 and 23 is smaller than the distance D13 between inductors 21 and 23.

[0151] Therefore, since the distance D23 is smaller than the distance D13, the coupling coefficient k23 between inductors 22 and 23 can be made larger than the coupling coefficient k13 between inductors 21 and 23. This suppresses the formation of a low-pass filter between inductors 23 and 21. Furthermore, good linearity is ensured at high frequencies through the feedback loop formed by the magnetic field coupling between inductors 23 and 22. Thus, the amplification characteristics of the low-noise amplifier circuit 1E can be widened.

[0152] Additionally, for example, the low-noise amplifier circuit 1F according to Modification 6 further includes a substrate 90 having opposing main surfaces 90a and 90b. Inductor 21 is formed by a spiral first wiring disposed on the substrate 90, inductor 22 is formed by a spiral second wiring disposed on the substrate 90, and inductor 23 is formed by a spiral third wiring disposed on the substrate 90. When viewed from above the main surface 90a, the winding axis of inductor 21 and the winding axis of inductor 23 are contained in the inner region of the second wiring. The first wiring is disposed on the main surface 90a side of the second wiring, and the third wiring is disposed on the main surface 90b side of the second wiring.

[0153] Therefore, since the distance D23 between inductors 22 and 23 is smaller than the distance D13 between inductors 21 and 23, the coupling coefficient k23 between inductors 22 and 23 can be made larger than the coupling coefficient k13 between inductors 21 and 23. This suppresses the formation of a low-pass filter between inductors 23 and 21. Furthermore, good linearity is ensured at high frequencies through the feedback loop formed by the magnetic field coupling between inductors 23 and 22. Thus, the amplification characteristics of the low-noise amplifier circuit 1F can be widened.

[0154] Additionally, for example, in the low-noise amplifier circuit involved in the embodiment, amplifier 10 includes FET 11, the gate terminal of FET 11 is the input terminal of amplifier 10, the source terminal of FET 11 is the ground connection terminal of amplifier 10, and the drain terminal of FET 11 is the output terminal of amplifier 10.

[0155] Therefore, a low-noise amplifier circuit can be constructed using a single-stage transistor.

[0156] Additionally, for example, in the low-noise amplifier circuit 1, the amplifier 10 includes FETs 11 and 12. The drain terminal D1 of FET 11 is connected to the source terminal S2 of FET 12. The gate terminal G1 of FET 11 is the input terminal of amplifier 10. The source terminal S1 of FET 11 is the ground connection terminal of amplifier 10. The drain terminal D2 of FET 12 is the output terminal of amplifier 10.

[0157] Therefore, a low-noise amplifier circuit can be constructed using cascaded two-stage transistors.

[0158] Additionally, for example, the low-noise amplifier circuit 1 also includes: a capacitor 31 connected between the input terminal 101 and one end of the inductor 21; a bias terminal 103 connected to the other end of the inductor 22; and a capacitor 33 connected between the other end of the inductor 22 and the bias terminal 103 and ground.

[0159] Thus, bias voltage (current) can be supplied to amplifier 10 via transmission line transformer 20.

[0160] Additionally, for example, the low-noise amplifier circuit 1A also includes: a capacitor 35 connected between the other end of the inductor 21 and the input terminal of the amplifier 10; and a bias terminal 103 connected between the capacitor 35 and the input terminal of the amplifier 10.

[0161] Therefore, the bias voltage (current) can be supplied to the amplifier 10 without passing through the transmission line transformer 20.

[0162] In addition, for example, in low-noise amplifier circuits 1, 1A to 1F, the coupling coefficient k12 between inductor 21 and inductor 22 is larger than the coupling coefficient k23 between inductor 22 and inductor 23.

[0163] Therefore, the degree of freedom in phase shift and impedance transformation in the transmission line transformer 20 can be greatly ensured.

[0164] (Other implementation methods)

[0165] The low-noise amplifier circuit of the present invention has been described above based on the embodiments, but the low-noise amplifier circuit of the present invention is not limited to the above embodiments. Other embodiments implemented by combining any of the constituent elements in the above embodiments, variations of the above embodiments that can be conceived by those skilled in the art without departing from the spirit of the present invention, and various machines that incorporate the above low-noise amplifier circuit are also included in the present invention.

[0166] For example, in the circuit configuration of the low-noise amplifier circuit according to the above embodiments, other circuit elements and wiring may be inserted between the paths connecting the circuit elements and signal paths disclosed in the drawings. For example, the low-noise amplifier circuit 1 may also include a bias circuit that applies a bias voltage to the FET 11.

[0167] Industrial availability

[0168] This invention, as a low-noise amplifier circuit configured at the front end, can be widely used in communication devices such as mobile phones.

Claims

1. A low-noise amplifier circuit, wherein, have: Input terminals and output terminals; An amplifier is connected between the aforementioned input terminal and the aforementioned output terminal; A transmission line transformer, comprising a first inductor and a second inductor, is connected between the aforementioned input terminal and the input terminal of the aforementioned amplifier. as well as The third inductor is connected between the ground connection terminal of the aforementioned amplifier and the ground. One end of the first inductor and one end of the second inductor are connected to the input terminal. The other end of the first inductor is connected to the input terminal of the amplifier. The other end of the second inductor is connected to ground. The coupling coefficient between the second inductor and the third inductor is greater than that between the first inductor and the third inductor.

2. The low-noise amplifier circuit according to claim 1, wherein, The aforementioned low-noise amplifier circuit also includes a substrate. The first inductor is formed by a first wiring disposed on the substrate. The second inductor is formed by a spiral second wiring disposed on the substrate. The aforementioned third inductor is formed by a third wiring disposed on the aforementioned substrate. One of the first wiring and the third wiring is disposed in the inner region of the second wiring from a top view of the substrate. The other of the first wiring and the third wiring is disposed in the outer region of the second wiring from the top view of the substrate.

3. The low-noise amplifier circuit according to claim 2, wherein, The first wiring and the third wiring described above are spiral-shaped. From a top view of the substrate, the winding shafts of the first inductor and the third inductor are contained within the inner region of the second wiring.

4. The low-noise amplifier circuit according to claim 1, wherein, The aforementioned low-noise amplifier circuit also includes a substrate. The first inductor, the second inductor, and the third inductor are formed by wiring disposed on the substrate. The distance between the second inductor and the third inductor is smaller than the distance between the first inductor and the third inductor.

5. The low-noise amplifier circuit according to claim 1, wherein, The aforementioned low-noise amplifier circuit also includes a substrate having a first main surface and a second main surface that are opposite to each other. The first inductor is formed by a spiral first wiring disposed on the substrate. The second inductor is formed by a spiral second wiring disposed on the substrate. The aforementioned third inductor is formed by a spiral third wiring disposed on the aforementioned substrate. Viewed from above on the first main surface, the winding shafts of the first inductor and the third inductor are contained within the inner region of the second wiring. The first wiring described above is configured on the first main surface side of the second wiring described above. The third wiring is configured on the second main surface side of the second wiring.

6. A low-noise amplifier circuit, wherein, have: substrate; Input terminals and output terminals; An amplifier is connected between the aforementioned input terminal and the aforementioned output terminal; A transmission line transformer, comprising a first inductor and a second inductor, is connected between the aforementioned input terminal and the input terminal of the aforementioned amplifier. as well as The third inductor is connected between the ground connection terminal of the aforementioned amplifier and the ground. One end of the first inductor and one end of the second inductor are connected to the input terminal. The other end of the first inductor is connected to the input terminal of the amplifier. The other end of the second inductor is connected to ground. The first inductor is formed by a first wiring disposed on the substrate. The second inductor is formed by a spiral second wiring disposed on the substrate. The aforementioned third inductor is formed by a third wiring disposed on the aforementioned substrate. One of the first wiring and the third wiring is disposed in the inner region of the second wiring from a top view of the substrate. The other of the first wiring and the third wiring is disposed in the outer region of the second wiring from the top view of the substrate.

7. The low-noise amplifier circuit according to claim 6, wherein, The first wiring and the third wiring described above are spiral-shaped. From a top view of the substrate, the winding shafts of the first inductor and the third inductor are contained within the inner region of the second wiring.

8. A low-noise amplifier circuit, wherein, have: substrate; Input terminals and output terminals; An amplifier is connected between the aforementioned input terminal and the aforementioned output terminal; A transmission line transformer, comprising a first inductor and a second inductor, is connected between the aforementioned input terminal and the input terminal of the aforementioned amplifier. as well as The third inductor is connected between the ground connection terminal of the aforementioned amplifier and the ground. One end of the first inductor and one end of the second inductor are connected to the input terminal. The other end of the first inductor is connected to the input terminal of the amplifier. The other end of the second inductor is connected to ground. The first inductor, the second inductor, and the third inductor are formed by wiring disposed on the substrate. The distance between the second inductor and the third inductor is smaller than the distance between the first inductor and the third inductor.

9. The low-noise amplifier circuit according to any one of claims 1 to 8, wherein, The amplifier described above includes a first FET. The gate terminal of the first FET is the input terminal. The source terminal of the first FET is the aforementioned ground connection terminal. The drain terminal of the first FET is the output terminal of the amplifier.

10. The low-noise amplifier circuit according to any one of claims 1 to 8, wherein, The amplifier described above includes a first FET and a second FET. The drain terminal of the first FET is connected to the source terminal of the second FET. The gate terminal of the first FET is the input terminal. The source terminal of the first FET is the aforementioned ground connection terminal. The drain terminal of the second FET is the output terminal of the amplifier.

11. The low-noise amplifier circuit according to any one of claims 1 to 10, wherein, The aforementioned low-noise amplifier circuit also features: A first capacitor is connected between the aforementioned input terminal and one end of the aforementioned first inductor; The bias terminal is connected to the other end of the second inductor; and The second capacitor is connected between the other end of the second inductor and the bias terminal and ground.

12. The low-noise amplifier circuit according to any one of claims 1 to 10, wherein, The aforementioned low-noise amplifier circuit also features: A first capacitor is connected between the other end of the first inductor and the input terminal of the amplifier; and The bias terminal is connected between the first capacitor and the input terminal of the amplifier.

13. The low-noise amplifier circuit according to any one of claims 1 to 12, wherein, The coupling coefficient between the first inductor and the second inductor is greater than the coupling coefficient between the second inductor and the third inductor.

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