High-frequency circuit, high-frequency module, and communication device

Abstract

Suppressing the degradation of the characteristics of high-frequency circuits. In the first balun (7) of the high-frequency circuit (100), the first end (711) of the first coil (71) is connected to the amplifier (3), and the second end (712) of the first coil (71) is connected to ground. In the first balun (7), the first end (721) of the second coil (72) is connected to the first switch (5), and the second end (722) of the second coil (72) is connected to the second switch (6). In the second balun (8), the first end (811) of the third coil (81) is connected to the first end (721) of the second coil (72) via the first switch (5), and the second end (812) of the third coil (81) is connected to the second end (722) of the second coil (72) via the second switch (6). In the second balanced-to-unbalanced converter (8), the first end (821) of the fourth coil (82) is connected to the filter (1), and the second end (822) of the fourth coil (82) is connected to ground.

Description

Technical Field

[0001] This invention generally relates to a high-frequency circuit, a high-frequency module, and a communication device; more specifically, it relates to a high-frequency circuit having an amplifier, a high-frequency module having a high-frequency circuit, and a communication device having a high-frequency circuit. Background Technology

[0002] Patent document 1 discloses a high-frequency circuit that includes a power amplifier, a filter, a switch connecting the power amplifier and the filter, and a switch connecting the filter and an antenna.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-17691 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] In high-frequency circuits, when high power is applied to devices such as filters and switches, signal distortion sometimes occurs in the devices, and the characteristics of the high-frequency circuit deteriorate.

[0008] The purpose of this invention is to provide a high-frequency circuit, a high-frequency module, and a communication device that can suppress the degradation of characteristics.

[0009] Solution for solving the problem

[0010] One aspect of the present invention relates to a high-frequency circuit comprising a filter, an amplifier, a first switch, a second switch, a first balun, and a second balun. The amplifier has an input terminal and an output terminal. The amplifier is connected to the filter. The first balun has a first coil and a second coil. The second balun has a third coil and a fourth coil. In the first balun, a first end of the first coil is connected to a terminal of the amplifier's input and output terminals connected to the filter, and a second end of the first coil is connected to ground. In the first balun, a first end of the second coil is connected to the first switch, and a second end of the second coil is connected to the second switch. In the second balun, a first end of the third coil is connected to the first end of the second coil via the first switch, and a second end of the third coil is connected to the second end of the second coil via the second switch. In the second balun, a first end of the fourth coil is connected to the filter, and a second end of the fourth coil is connected to ground.

[0011] One aspect of the present invention relates to a high-frequency circuit comprising a first filter, a second filter, an amplifier, a first switch, a second switch, a first balun, and a second balun. The first filter has a first passband. The second filter has a second passband identical to the first passband. The amplifier has an input terminal and an output terminal. The amplifier is connected to the first filter and the second filter. The first balun has a first coil and a second coil. The second balun has a third coil and a fourth coil. In the first balun, a first end of the first coil is connected to a terminal of the amplifier's input or output that is connected to the first filter and the second filter, and a second end of the first coil is connected to ground. In the first balun, a first end of the second coil is connected to the first switch, and a second end of the second coil is connected to the second switch. In the second balun, a first end of the third coil is connected to the first end of the second coil via the first filter and the first switch, and a second end of the third coil is connected to the second end of the second coil via the second filter and the second switch. In the second balun, the first end of the fourth coil is connected to the signal path, and the second end of the fourth coil is connected to ground.

[0012] One embodiment of the present invention relates to a high-frequency module comprising the aforementioned high-frequency circuit and a mounting substrate. The amplifier, the first switch, the second switch, the first balun, and the second balun of the high-frequency circuit are disposed on the mounting substrate.

[0013] One embodiment of the present invention relates to a communication device comprising the aforementioned high-frequency circuit and signal processing circuit. The signal processing circuit is connected to the high-frequency circuit.

[0014] The effects of the invention

[0015] The high-frequency circuit, high-frequency module, and communication device described above by the present invention can suppress the degradation of the characteristics of the high-frequency circuit. Attached Figure Description

[0016] Figure 1 This is a circuit structure diagram of a communication device having the high-frequency circuit described in Embodiment 1.

[0017] Figure 2 It is the circuit diagram of the same high-frequency circuit as above.

[0018] Figure 3 A is a cross-sectional view of a high-frequency module with the same high-frequency circuit as above. Figure 3 B is another cross-sectional view of a high-frequency module with the same high-frequency circuit as above.

[0019] Figure 4 This is a bottom view of a high-frequency module with the same high-frequency circuitry as described above.

[0020] Figure 5 This is a circuit diagram of the high-frequency circuit involved in Implementation Method 2.

[0021] Figure 6 It is a cross-sectional view of a high-frequency module with the same high-frequency circuit as above.

[0022] Figure 7 This is a cross-sectional view of the high-frequency circuit involved in Implementation Method 3.

[0023] Figure 8 This is a circuit diagram of the high-frequency circuit involved in Implementation Method 4.

[0024] Figure 9 It is a cross-sectional view of a high-frequency module with the same high-frequency circuit as above.

[0025] Figure 10 This is a bottom view of a high-frequency module with the same high-frequency circuitry as described above.

[0026] Figure 11 This is a circuit diagram of the high-frequency circuit involved in Implementation Method 5.

[0027] Figure 12 This is a circuit diagram of the high-frequency circuit involved in Implementation Method 6.

[0028] Figure 13 This is a circuit diagram of the high-frequency circuit involved in Implementation Method 7.

[0029] Figure 14 This is a circuit diagram of the high-frequency circuit involved in Implementation Method 8.

[0030] Figure 15 This is a circuit diagram of the high-frequency circuit involved in Implementation Method 9.

[0031] Figure 16 This is a circuit diagram of the high-frequency circuit involved in Implementation Method 10.

[0032] Figure 17 This is a circuit diagram of the high-frequency circuit involved in Implementation Method 11.

[0033] Figure 18 This is a circuit diagram of the high-frequency circuit involved in Implementation Method 12.

[0034] Figure 19 This is a circuit diagram of the high-frequency circuit involved in Implementation Method 13. Detailed Implementation

[0035] The figures referenced in the following embodiments are schematic diagrams, and the size ratios and thickness ratios of the structural elements in the figures may not reflect the actual size ratios.

[0036] (Implementation Method 1)

[0037] Below, based on Figures 1-4 To illustrate the high-frequency circuit 100, high-frequency module 500, and communication device 600 involved in Embodiment 1.

[0038] like Figure 1 As shown, the high-frequency circuit 100 includes a filter 1 (transmitting filter 11), an amplifier 3 (power amplifier 31), a first switch 5, a second switch 6, a first balun 7, and a second balun 8. The amplifier 3 has input and output terminals. The amplifier 3 is connected to the filter 1. Figure 2 As shown, the first balun 7 has a first coil 71 and a second coil 72. Figure 2 As shown, the second balun 8 has a third coil 81 and a fourth coil 82. In the first balun 7, the first end 711 of the first coil 71 is connected to the output terminal of the amplifier 3, and the second end 712 of the first coil 71 is connected to ground. In the first balun 7, the first end 721 of the second coil 72 is connected to the first switch 5, and the second end 722 of the second coil 72 is connected to the second switch 6. In the second balun 8, the first end 811 of the third coil 81 is connected to the first end 721 of the second coil 72 via the first switch 5, and the second end 812 of the third coil 81 is connected to the second end 722 of the second coil 72 via the second switch 6. In the second balun 8, the first end 821 of the fourth coil 82 is connected to the filter 1, and the second end 822 of the fourth coil 82 is connected to ground.

[0039] In addition, such as Figure 1 As shown, the high-frequency circuit 100 also includes a second filter 2 (transmit filter 12) different from filter 1 (hereinafter also referred to as the first filter 1). The first filter has a first passband. The second filter 2 has a second passband different from the first passband. In addition, the high-frequency circuit 100 also includes a second amplifier 4 (power amplifier 32), which is a second amplifier 4 (power amplifier 32) other than amplifier 3 (hereinafter also referred to as the first amplifier 3). The second amplifier 4 has input terminals and output terminals, and is connected to the second filter 2.

[0040] In addition, the high-frequency circuit 100 also includes multiple (two in the example) receiver filters 21, 22 and multiple (two in the example) low-noise amplifiers 41, 42.

[0041] In addition, the high-frequency circuit 100 also includes an antenna terminal T1 and a third switch 10. The third switch 10 is connected between the antenna terminal T1 and the second balun 8. Furthermore, the high-frequency circuit 100 also includes a second antenna terminal T2, which is an additional antenna terminal besides the antenna terminal T1. The third switch 10 is configured to connect the first filter 1 to the first antenna terminal T1 and to connect the second filter 2 to the second antenna terminal T2.

[0042] The first filter 1 (transmitting filter 11) has a first passband that includes the frequency band of the first communication frequency band. The second filter 2 (transmitting filter 12) has a second passband that includes the frequency band of the second communication frequency band capable of simultaneous communication with the first communication frequency band. Additionally, the receiving filter 21 has a passband that includes the frequency band of the first communication frequency band. The receiving filter 22 has a passband that includes the frequency band of the second communication frequency band. "Capable of simultaneous communication" means capable of simultaneous reception, simultaneous transmission, and simultaneous transmission and reception at least one of these. In the high-frequency circuit 100, the combination of the first communication frequency band and the second communication frequency band is a combination capable of simultaneous reception, simultaneous transmission, and simultaneous transmission and reception in the high-frequency circuit 100.

[0043] like Figure 1 As shown, the high-frequency circuit 100 is used, for example, in the communication device 600. The communication device 600 is, for example, a portable telephone (e.g., a smartphone), but is not limited to this; it could also be a wearable terminal (e.g., a smartwatch). The high-frequency circuit 100 is, for example, a high-frequency front-end circuit capable of supporting 4G (fourth-generation mobile communication) standards, 5G (fifth-generation mobile communication) standards, etc. The 4G standard is, for example, the 3GPP (Third Generation Partnership Project) LTE (Long Term Evolution) standard. The 5G standard is, for example, 5G NR (New Radio). The high-frequency circuit 100 is, for example, a high-frequency front-end circuit capable of supporting carrier aggregation and dual connectivity. The combination of the first and second communication frequency bands capable of simultaneous communication is a combination of multiple frequency bands, some overlapping and some not overlapping, from the frequency bands of the communication frequency bands specified in the 3GPP LTE standard and the frequency bands of the communication frequency bands specified in the 5G NR standard. The frequency band is a downlink frequency band or an uplink frequency band. The downlink frequency band is the receive frequency band. The uplink frequency band is the transmit frequency band.

[0044] The high-frequency circuit 100 is configured, for example, to amplify and output a transmit signal (high-frequency signal) of a first frequency band input from the signal processing circuit 601 to antenna A1 (hereinafter also referred to as the first antenna A1). Furthermore, the high-frequency circuit 100 is configured to amplify and output a transmit signal (high-frequency signal) of a second frequency band input from the signal processing circuit 601 to antenna A2 (hereinafter also referred to as the second antenna A2). Additionally, the high-frequency circuit 100 is configured to amplify and output a receive signal (high-frequency signal) of the first frequency band input from the first antenna A1 to the signal processing circuit 601. Furthermore, the high-frequency circuit 100 is configured to amplify and output a receive signal (high-frequency signal) of the second frequency band input from the second antenna A2 to the signal processing circuit 601. The signal processing circuit 601 is not a structural element of the high-frequency circuit 100, but rather a structural element of the communication device 600 equipped with the high-frequency circuit 100. The high-frequency circuit 100 is controlled, for example, by the signal processing circuit 601 included in the communication device 600. The communication device 600 includes the high-frequency circuit 100 and the signal processing circuit 601. The communication device 600 also includes a first antenna A1 and a second antenna A2. The high-frequency module 500 includes a high-frequency circuit 100 and a mounting substrate 501 (see reference). Figure 3 A, Figure 3 B and Figure 4 ).

[0045] The high-frequency circuit 100, the high-frequency module 500, and the communication device 600 involved in Embodiment 1 will be described in further detail below.

[0046] (1) High-frequency circuits

[0047] (1.1) Circuit structure of high-frequency circuits

[0048] like Figure 1 As shown, the high-frequency circuit 100 includes, for example, multiple (e.g., two) transmitting filters 11 and 12, multiple (e.g., two) power amplifiers 31 and 32, and a controller 13. Additionally, the high-frequency circuit 100 includes multiple (e.g., two) receiving filters 21 and 22, and multiple (e.g., two) low-noise amplifiers 41 and 42. Furthermore, the high-frequency circuit 100 includes a first switch 5, a second switch 6, a third switch 10, a fourth switch 14, a fifth switch 15, a sixth switch 16, a first balun 7, and a second balun 8. Additionally, the high-frequency circuit 100 includes a first matching circuit M1 (see reference...). Figure 2 ) and the second matching circuit M2 (refer to Figure 2In addition, the high-frequency circuit 100 also includes a controller 13. Furthermore, the high-frequency circuit 100 also includes a first antenna terminal T1, a second antenna terminal T2, a first signal input terminal T3, a second signal input terminal T4, a first signal output terminal T5, a second signal output terminal T6, and a control terminal T7.

[0049] (1.1.1) Transmit Filter

[0050] For ease of explanation, the transmitting filter 11 will be referred to as the first transmitting filter 11, and the transmitting filter 12 will be referred to as the second transmitting filter 12. In the high-frequency circuit 100 according to Embodiment 1, the first transmitting filter 11 constitutes the first filter 1 described above, and the second transmitting filter 12 constitutes the second filter 2 described above. The multiple transmitting filters 11 and 12 are, for example, elastic wave filters. The elastic wave filter is, for example, a trapezoidal filter having multiple (e.g., 4) series-arm resonators and multiple (e.g., 3) parallel-arm resonators. Each resonator in the multiple series-arm resonators and multiple parallel-arm resonators of the elastic wave filter is an elastic wave resonator. The elastic wave filter is, for example, a surface acoustic wave (SAW) filter utilizing surface acoustic waves. In the SAW filter, each resonator in the multiple series-arm resonators and multiple parallel-arm resonators is, for example, a SAW (Surface Acoustic Wave) resonator including IDT (Interdigital Transducer) electrodes.

[0051] The first transmit filter 11 is a filter having a passband that includes the uplink band of the first communication frequency band. The second transmit filter 12 is a filter having a passband that includes the uplink band of the second communication frequency band. The first communication frequency band is, for example, Band 25 of the 3GPP LTE standard. The second communication frequency band is, for example, Band 66 of the 3GPP LTE standard.

[0052] (1.1.2) Power Amplifier

[0053] For ease of explanation, power amplifier 31 will be referred to as first power amplifier 31, and power amplifier 32 will be referred to as second power amplifier 32. In the high-frequency circuit 100 according to Embodiment 1, first power amplifier 31 constitutes the first amplifier 3 described above, and second power amplifier 32 constitutes the second amplifier 4 described above.

[0054] The first power amplifier 31 has an input terminal and an output terminal. The first power amplifier 31 amplifies the transmitted signal (first transmitted signal) input to the input terminal in a first frequency band and outputs it from the output terminal. The first frequency band, for example, includes the frequency band of a first communication frequency band but does not include the frequency band of a second communication frequency band. More specifically, the first frequency band, for example, includes the uplink frequency band of Band 25 of the 3GPP LTE standard but does not include the uplink frequency band of Band 66 of the 3GPP LTE standard. Additionally, the first frequency band, for example, also includes the uplink frequency band of Band 3 and the uplink frequency band of Band 34 of the 3GPP LTE standard.

[0055] The input terminal of the first power amplifier 31 is connected to the first signal input terminal T3. The input terminal of the first power amplifier 31 is connected to the signal processing circuit 601 via the first signal input terminal T3. The first signal input terminal T3 is used to input a high-frequency signal (transmit signal) from an external circuit (e.g., the signal processing circuit 601) into the high-frequency circuit 100. The output terminal of the first power amplifier 31 is connected to the first balun 7. Therefore, the output terminal of the first power amplifier 31 is connected to the first switch 5 and the second switch 6 via the first balun 7. In the high-frequency circuit 100, the first switch 5 and the second switch 6 are connected to the second balun 8, and the second balun 8 is connected to the first transmit filter 11.

[0056] The second power amplifier 32 has an input terminal and an output terminal. The second power amplifier 32 amplifies the transmission signal (second transmission signal) of the second frequency band input to the input terminal and outputs it from the output terminal. The second frequency band includes, for example, the frequency band of the second communication frequency band, but does not include the frequency band of the first communication frequency band.

[0057] The input terminal of the second power amplifier 32 is connected to the second signal input terminal T4. The input terminal of the second power amplifier 32 is connected to the signal processing circuit 601 via the second signal input terminal T4. The second signal input terminal T4 is a terminal for inputting a high-frequency signal (transmit signal) from an external circuit (e.g., the signal processing circuit 601) to the high-frequency circuit 100. The output terminal of the second power amplifier 32 is connected to the transmit filter 12 (second filter 2).

[0058] (1.1.3) Controller

[0059] Controller 13 is connected to control terminal T7. Control terminal T7 is connected, for example, to signal processing circuit 601. Controller 13 controls the first power amplifier 31 based on control signals from signal processing circuit 601. In addition, controller 13 also controls the second power amplifier 32 based on control signals from signal processing circuit 601.

[0060] (1.1.4) Receiver Filter

[0061] For ease of explanation, receiving filter 21 will be referred to as the first receiving filter 21, and receiving filter 22 will be referred to as the second receiving filter 22. The multiple receiving filters 21 and 22 are, for example, elastic wave filters. The elastic wave filter is, for example, a trapezoidal filter having multiple (e.g., four) series-arm resonators and multiple (e.g., three) parallel-arm resonators. Each resonator in the multiple series-arm and multiple parallel-arm resonators of the elastic wave filter is an elastic wave resonator. The elastic wave filter is, for example, a surface acoustic wave (SAW) filter utilizing surface acoustic waves. In the SAW filter, each resonator in the multiple series-arm and multiple parallel-arm resonators is, for example, a SAW resonator including an IDT electrode.

[0062] The first receiving filter 21 is a filter having a passband that includes the downlink band of the first communication frequency band. The second receiving filter 22 is a filter having a passband that includes the downlink band of the second communication frequency band. The first communication frequency band is, for example, Band 25 of the 3GPP LTE standard. The second communication frequency band is, for example, Band 66 of the 3GPP LTE standard.

[0063] (1.1.5) Low-noise amplifier

[0064] For ease of explanation, the low-noise amplifier 41 will be referred to as the first low-noise amplifier 41, and the low-noise amplifier 42 will be referred to as the second low-noise amplifier 42.

[0065] The first low-noise amplifier 41 has an input terminal and an output terminal. The first low-noise amplifier 41 amplifies the received signal of the third frequency band input to the input terminal and outputs it from the output terminal. The third frequency band, for example, includes the frequency band of the first communication frequency band but excludes the frequency band of the second communication frequency band. More specifically, the third frequency band, for example, includes the downlink frequency band of Band 25 of the 3GPP LTE standard but excludes the downlink frequency band of Band 66 of the 3GPP LTE standard. Additionally, the third frequency band, for example, also includes the downlink frequency band of Band 70 of the 3GPP LTE standard.

[0066] The input terminal of the first low-noise amplifier 41 is connected to the common terminal 140 of the fourth switch 14, and is connected to the first receiving filter 21 via the fourth switch 14. The output terminal of the first low-noise amplifier 41 is connected to the sixth switch 16, and is connected to the first signal output terminal T5 via the sixth switch 16. The first signal output terminal T5 is used to output the high-frequency signal (received signal) from the first low-noise amplifier 41 to an external circuit (e.g., signal processing circuit 601). Therefore, the first low-noise amplifier 41 is connected to the signal processing circuit 601 via the first signal output terminal T5.

[0067] The second low-noise amplifier 42 has an input terminal and an output terminal. The second low-noise amplifier 42 amplifies the received signal of the fourth frequency band input to the input terminal and outputs it from the output terminal. The fourth frequency band, for example, includes the frequency band of the second communication frequency band but does not include the frequency band of the first communication frequency band. More specifically, the fourth frequency band, for example, includes the downlink frequency band of Band 66 of the 3GPP LTE standard but does not include the downlink frequency band of Band 25 of the 3GPP LTE standard.

[0068] The input terminal of the second low-noise amplifier 42 is connected to the common terminal 150 of the fifth switch 15, and is also connected to the second receiving filter 22 via the fifth switch 15. The output terminal of the second low-noise amplifier 42 is connected to the sixth switch 16, and is also connected to the second signal output terminal T6 via the sixth switch 16. The second signal output terminal T6 is used to output the high-frequency signal (received signal) from the second low-noise amplifier 42 to an external circuit (e.g., signal processing circuit 601). Therefore, the second low-noise amplifier 42 is connected to the signal processing circuit 601 via the second signal output terminal T6.

[0069] (1.1.6) First switch

[0070] The first switch 5 has a common terminal 50 and multiple (three in the example) selector terminals 51-53. The common terminal 50 is connected to the first end 721 of the second coil 72 in the first balun 7 (see reference). Figure 2 Select terminal 51 is connected to the first end 811 of the third coil 81 in the second balun 8 (see reference). Figure 2 The first switch 5 is, for example, a switch capable of connecting at least one of the three selector terminals 51 to 53 to the common terminal 50. Here, the first switch 5 is, for example, a switch capable of one-to-one and one-to-many connections.

[0071] The first switch 5 is controlled, for example, by a signal processing circuit 601. The first switch 5 switches the connection state between the common terminal 50 and the three selection terminals 51 to 53 according to the control signal from the RF signal processing circuit 602 of the signal processing circuit 601. The first switch 5 is, for example, a switch IC (Integrated Circuit).

[0072] (1.1.7) Second switch

[0073] The second switch 6 has a common terminal 60 and multiple (three in the example) selector terminals 61-63. The common terminal 60 is connected to the second end 722 of the second coil 72 in the first balun 7 (see reference). Figure 2 Select terminal 61 is connected to the second end 812 of the third coil 81 in the second balun 8 (see reference). Figure 2 The second switch 6 is, for example, a switch capable of connecting at least one of the three selector terminals 61 to 63 to the common terminal 60. Here, the second switch 6 is, for example, a switch capable of one-to-one and one-to-many connections.

[0074] The second switch 6 is controlled, for example, by a signal processing circuit 601. The second switch 6 switches the connection state between the common terminal 60 and the three selection terminals 61-63 according to a control signal from the RF signal processing circuit 602 of the signal processing circuit 601. The second switch 6 is, for example, a switch IC.

[0075] (1.1.8) Third switch

[0076] The third switch 10 has two first terminals 101 and 102 and multiple (two in the example) second terminals 111 and 112. First terminal 101 is connected to the first antenna terminal T1. First terminal 102 is connected to the second antenna terminal T2. Second terminal 111 is connected to the first transmitting filter 11 and the first receiving filter 21. More specifically, second terminal 111 is connected to the junction of the output terminal of the first transmitting filter 11 and the input terminal of the first receiving filter 21. Second terminal 112 is connected to the second transmitting filter 12 and the second receiving filter 22. More specifically, second terminal 112 is connected to the junction of the output terminal of the second transmitting filter 12 and the input terminal of the second receiving filter 22.

[0077] In the third switch 10, the first terminal 101 can be connected to the second terminal 111, and the first terminal 102 can be connected to the second terminal 112.

[0078] The third switch 10 is controlled, for example, by a signal processing circuit 601. The third switch 10 switches the connection state of the first terminals 101, 102 and the second terminals 111, 112 according to the control signal from the RF signal processing circuit 602 of the signal processing circuit 601. The third switch 10 is, for example, a switch IC.

[0079] (1.1.9) Fourth switch

[0080] The fourth switch 14 has a common terminal 140 and multiple (three in the example) select terminals 141-143. The common terminal 140 is connected to the input terminal of the first low-noise amplifier 41. The select terminals 141 are connected to the output terminal of the first receiving filter 21. The fourth switch 14 is, for example, a switch capable of connecting the common terminal 140 to at least one of the multiple select terminals 141-143. Here, the fourth switch 14 is, for example, a switch capable of both one-to-one and one-to-many connections.

[0081] The fourth switch 14 is controlled, for example, by the signal processing circuit 601. The fourth switch 14 switches the connection state between the common terminal 140 and the multiple selection terminals 141-143 according to the control signal from the RF signal processing circuit 602 of the signal processing circuit 601. The fourth switch 14 is, for example, a switch IC.

[0082] (1.1.10) Fifth Switch

[0083] The fifth switch 15 has a common terminal 150 and multiple (three in the example) select terminals 151-153. The common terminal 150 is connected to the input terminal of the second low-noise amplifier 42. The select terminals 151 are connected to the output terminal of the second receiving filter 22. The fifth switch 15 is, for example, a switch capable of connecting the common terminal 150 to at least one of the multiple select terminals 151-153. Here, the fifth switch 15 is, for example, a switch capable of both one-to-one and one-to-many connections.

[0084] The fifth switch 15 is controlled, for example, by the signal processing circuit 601. The fifth switch 15 switches the connection state between the common terminal 150 and the multiple selection terminals 151-153 according to the control signal from the RF signal processing circuit 602 of the signal processing circuit 601. The fifth switch 15 is, for example, a switch IC.

[0085] (1.1.11) Sixth Switch

[0086] The sixth switch 16 has two first terminals 161 and 162 and multiple (two in the example shown) second terminals 165 and 166. First terminal 161 is connected to the first signal output terminal T5. First terminal 162 is connected to the second signal output terminal T6. Second terminal 165 is connected to the output terminal of the first low-noise amplifier 41. Second terminal 166 is connected to the output terminal of the second low-noise amplifier 42.

[0087] In the sixth switch 16, the first terminal 161 can be connected to the second terminal 165, and the first terminal 162 can be connected to the second terminal 166.

[0088] The sixth switch 16 is controlled, for example, by the signal processing circuit 601. The sixth switch 16 switches the connection states of the first terminals 161, 162 and the second terminals 165, 166 according to the control signal from the RF signal processing circuit 602 of the signal processing circuit 601. The sixth switch 16 is, for example, a switch IC.

[0089] (1.1.12) First Balanced-Unbalanced Converter

[0090] like Figure 2 As shown, the first balun 7 has a first coil 71 and a second coil 72. The first coil 71 and the second coil 72 face each other. In the first balun 7, the first end 711 of the first coil 71 is connected to the amplifier 3, and the second end 712 of the first coil 71 is connected to ground. In the first balun 7, the first end 721 of the second coil 72 is connected to the first switch 5, and the second end 722 of the second coil 72 is connected to the second switch 6.

[0091] The first balun 7 converts the high-frequency signal (unbalanced signal) input to the first terminal 711 (unbalanced terminal) of the first coil 71 into a pair of high-frequency signals (first high-frequency signal and second high-frequency signal). The first high-frequency signal is output from the first terminal 721 (first balanced terminal) of the second coil 72, and the second high-frequency signal is output from the second terminal 722 (second balanced terminal) of the second coil 72. The phases of the first and second high-frequency signals are opposite. In the first balun 7, the first terminal 711 of the first coil 71 constitutes an unbalanced terminal, but is not limited thereto. For example, the first balun 7 may also have an unbalanced terminal connected to the first terminal 711. Furthermore, in the first balun 7, the first terminal 721 and the second terminal 722 of the second coil 72 constitute a pair of balanced terminals, but is not limited thereto. For example, the first balun 7 may also have a pair of balanced terminals connected one-to-one to the first terminal 721 and the second terminal 722 of the second coil 72.

[0092] (1.1.13) Second Balanced-Unbalanced Converter

[0093] like Figure 2 As shown, the second balun 8 has a third coil 81 and a fourth coil 82. The third coil 81 and the fourth coil 82 face each other. In the second balun 8, the first end 811 of the third coil 81 is connected to the first end 721 of the second coil 72 via a first switch 5, and the second end 812 of the third coil 81 is connected to the first end 721 of the second coil 72 via a second switch 6. In the second balun 8, the first end 821 of the fourth coil 82 is connected to the filter 1, and the second end 822 of the fourth coil 82 is connected to ground.

[0094] The second balun 8 converts a pair of high-frequency signals (a first high-frequency signal and a second high-frequency signal) input to the first terminal 811 and the second terminal 812 of the third coil 81 into an unbalanced high-frequency signal, which is then output from the first terminal 821 of the fourth coil 82. In the second balun 8, the first terminal 811 and the second terminal 812 of the third coil 81 constitute a pair of balanced terminals, but this is not a limitation. For example, the second balun 8 may also have a pair of balanced terminals connected one-to-one with the first terminal 811 and the second terminal 812 of the third coil 81. Furthermore, in the second balun 8, the first terminal 821 of the fourth coil 82 constitutes an unbalanced terminal, but this is not a limitation. For example, the second balun 8 may also have an unbalanced terminal connected to the first terminal 821.

[0095] (1.1.14) First matching circuit and second matching circuit

[0096] The first matching circuit M1 is an impedance matching circuit. The first matching circuit M1 is connected between the second coil 72 of the first balun 7 and the first switch 5. More specifically, the first matching circuit M1 is connected between the first terminal 721 of the second coil 72 of the first balun 7 and the common terminal 50 of the first switch 5. The first matching circuit M1 includes at least one of an inductor, a capacitor, and a resistor. The second matching circuit M2 is an impedance matching circuit. The second matching circuit M2 is connected between the second coil 72 of the first balun 7 and the second switch 6. More specifically, the second matching circuit M2 is connected between the second terminal 722 of the second coil 72 of the first balun 7 and the common terminal 60 of the second switch 6.

[0097] (1.2) Summary

[0098] The high-frequency circuit 100 according to Embodiment 1 includes a filter 1 (transmitting filter 11), an amplifier 3 (power amplifier 31), a first switch 5, a second switch 6, a first balun 7, and a second balun 8. The amplifier 3 has input and output terminals. The amplifier 3 is connected to the filter 1. The first balun 7 has a first coil 71 and a second coil 72. The second balun 8 has a third coil 81 and a fourth coil 82. In the first balun 7, the first end 711 of the first coil 71 is connected to the output terminal of the amplifier 3, and the second end 712 of the first coil 71 is connected to ground. In the first balun 7, the first end 721 of the second coil 72 is connected to the first switch 5, and the second end 722 of the second coil 72 is connected to the second switch 6. In the second balun 8, the first end 811 of the third coil 81 is connected to the first end 721 of the second coil 72 via the first switch 5, and the second end 812 of the third coil 81 is connected to the second end 722 of the second coil 72 via the second switch 6. In the second balun 8, the first end 821 of the fourth coil 82 is connected to the filter 1, and the second end 822 of the fourth coil 82 is connected to ground.

[0099] The high-frequency circuit 100 according to Embodiment 1 can suppress the degradation of its characteristics. More specifically, in the high-frequency circuit 100, switches (first switch 5 and second switch 6), which are nonlinear devices, are connected between the first balun 7 and the second balun 8, thus reducing the power applied to the switches (first switch 5 and second switch 6). Therefore, the high-frequency circuit 100 can reduce signal distortion of the high-frequency signal at the switches (first switch 5 and second switch 6) and suppress the degradation of its characteristics. Furthermore, the high-frequency circuit 100 according to Embodiment 1 can reduce high-frequency signal distortion by reducing the power applied to the switches (first switch 5 and second switch 6) and the filter 1, and the resulting suppression effect on the temperature rise of the switches (first switch 5 and second switch 6) and the filter 1.

[0100] Furthermore, in the high-frequency circuit 100 according to Embodiment 1, amplifier 3 is a power amplifier 31 that amplifies the transmitted signal. The first balun 7 is connected to the output terminal of amplifier 3. Therefore, the high-frequency circuit 100 according to Embodiment 1 can suppress signal distortion of the high-frequency signal (transmitted signal) at the switches (first switch 5 and second switch 6).

[0101] Furthermore, the high-frequency circuit 100 according to Embodiment 1 also includes: a second filter 2, which is different from the first filter 1; and a second amplifier 4, which is an amplifier other than the first amplifier 3 that is an amplifier 3, having input terminals and output terminals, and connected to the second filter 2. The first filter 1 has a first passband. The second filter 2 has a second passband that is different from the first passband.

[0102] The high-frequency circuit 100 involved in Embodiment 1 can, for example, reduce the magnitude of IMD (Intermodulation Distortion) that occurs when performing dual uplink carrier aggregation using the first amplifier 3 (first power amplifier 31) and the second amplifier 4 (second power amplifier 32).

[0103] (2) High-frequency module

[0104] Below, based on Figure 3 A, Figure 3 B and Figure 4 To explain in more detail the high-frequency module 500, which includes high-frequency circuitry 100. Furthermore, Figure 3 A is with Figure 4 The cross-sectional view corresponding to the X1-X1 line section. Additionally, Figure 3 B is with Figure 4 The cross-sectional diagram corresponding to the X2-X2 line section.

[0105] (2.1) Structure of the high-frequency module

[0106] The high-frequency module 500 includes a high-frequency circuit 100 and a mounting substrate 501. The mounting substrate 501 has a first main surface 511 and a second main surface 512 facing each other. An amplifier 3 is disposed on the first main surface 511 of the mounting substrate 501. A first switch 5 and a second switch 6 are disposed on the second main surface 512 of the mounting substrate 501. A first balun 7 and a second balun 8 are disposed on the mounting substrate 501. Additionally, in the high-frequency module 500, a plurality of external connection terminals T0 are disposed on the second main surface 512 of the mounting substrate 501. Furthermore, the high-frequency module 500 also includes a resin layer 520 (hereinafter also referred to as the first resin layer 520) and a metal electrode layer 530. Additionally, the high-frequency module 500 also includes a second resin layer 540.

[0107] (2.1.1) Mounting the substrate

[0108] like Figure 3 A and Figure 3As shown in Figure B, the mounting substrate 501 has a first main surface 511 and a second main surface 512 facing each other in the thickness direction D1 of the mounting substrate 501. The mounting substrate 501 includes multiple dielectric layers, multiple conductive layers, and multiple conductive paths. In the mounting substrate 501, the multiple dielectric layers and the multiple conductive layers are alternately stacked layer by layer in the thickness direction D1 of the mounting substrate 501. That is, the mounting substrate 501 is a multilayer substrate including multiple dielectric layers and multiple conductive layers. The multiple conductive layers are formed in a predetermined pattern defined for each layer. Each of the multiple conductive layers includes one or more conductor portions. The mounting substrate 501 is, for example, an LTCC (Low Temperature Co-fired Ceramics) substrate. When the mounting substrate 501 is an LTCC substrate, the material of each dielectric layer is, for example, a ceramic comprising alumina and glass. In addition, the material of each conductive layer is, for example, copper. The material of each conductive layer is not limited to copper; for example, silver may also be used. Mounting substrate 501 is not limited to LTCC substrates; for example, it can also be a printed circuit board, HTCC (High Temperature Co-fired Ceramics) substrate, or resin multilayer substrate.

[0109] The first main surface 511 and the second main surface 512 of the mounting substrate 501 are separated from and intersect the thickness direction D1 of the mounting substrate 501. The first main surface 511 of the mounting substrate 501 includes a surface orthogonal to the thickness direction D1 and a surface not orthogonal to the thickness direction D1. Similarly, the second main surface 512 of the mounting substrate 501 may be orthogonal to the thickness direction D1, for example, but may also include, for example, the side surface of the conductor portion as a surface not orthogonal to the thickness direction D1.

[0110] One of the multiple conductive layers includes a ground layer. The ground layer is the circuit ground of the high-frequency module 500. The ground layer is connected to the ground terminal T8 via a conductor or the like. In addition, the ground layer is electrically connected to the metal electrode layer 530. The ground layer is connected to the metal electrode layer 530.

[0111] (2.1.2) Electronic components

[0112] In the high-frequency module 500, multiple electronic components are mounted on a first main surface 511 of a mounting substrate 501, and multiple electronic components are mounted on a second main surface 512 of the mounting substrate 501. "Electronic components mounted on the first main surface 511 of the mounting substrate 501" includes the following situations: the electronic components are configured (mechanically connected to) the first main surface 511 of the mounting substrate 501; and the electronic components are electrically connected to (appropriate conductor portions) of the mounting substrate 501. "Electronic components mounted on the second main surface 512 of the mounting substrate 501" includes the following situations: the electronic components are configured (mechanically connected to) the second main surface 512 of the mounting substrate 501; and the electronic components are electrically connected to (appropriate conductor portions) of the mounting substrate 501. The multiple electronic components mounted on the first main surface 511 of the mounting substrate 501 include a first power amplifier 31 (first amplifier 3), a second power amplifier 32 (second amplifier 4), a first transmit filter 11 (first filter 1), a second transmit filter 12 (second filter 2), multiple circuit elements M11 of a first matching circuit M1, and multiple circuit elements M12 of a second matching circuit M2. Multiple electronic components mounted on the second main surface 512 of the mounting substrate 501 include a first low-noise amplifier 41, a second low-noise amplifier 42, a first switch 5, a second switch 6, a third switch 10, a fourth switch 14, a fifth switch 15, and a sixth switch 16. The first power amplifier 31 and the second power amplifier 32 are, for example, GaAs-based chips. The first low-noise amplifier 41, the second low-noise amplifier 42, the first switch 5, the second switch 6, the third switch 10, the fourth switch 14, the fifth switch 15, and the sixth switch 16 are Si-based chips. Multiple circuit elements M11 of the first matching circuit M1 include, for example, chip inductors, chip capacitors, and chip resistors. Multiple circuit elements M12 of the second matching circuit M2 include, for example, chip inductors, chip capacitors, and chip resistors. The circuit structure of the first matching circuit M1 is the same as the circuit structure of the second matching circuit M2. The first matching circuit M1 is not limited to a structure including multiple circuit elements M11. The second matching circuit M2 is not limited to a structure including multiple circuit elements M12. Alternatively, the first matching circuit M1 and the second matching circuit M2 can be IPD (Integrated Passive Device).

[0113] When viewed from the thickness direction D1 of the mounting substrate 501, the outer edges of the plurality of electronic components mounted on the first main surface 511 of the mounting substrate 501 are each quadrilateral in shape. Furthermore, when viewed from the thickness direction D1 of the mounting substrate 501, the outer edges of the plurality of electronic components mounted on the second main surface 512 of the mounting substrate 501 are each quadrilateral in shape.

[0114] (2.1.3) First Balanced-to-Unbalanced Converter and Second Balanced-to-Unbalanced Converter

[0115] The first balun 7 and the second balun 8 in the high-frequency circuit 100 are integrated into the mounting substrate 501. The first coil 71 of the first balun 7 includes a first conductor pattern portion P1 that intersects (e.g., orthogonally) the thickness direction D1 of the mounting substrate 501. The second coil 72 of the first balun 7 includes a second conductor pattern portion P2 that intersects (e.g., orthogonally) the thickness direction D1 of the mounting substrate 501 and faces the first conductor pattern portion P1 in the thickness direction D1 of the mounting substrate 501. When viewed from above in the thickness direction D1 of the mounting substrate 501, the first coil 71 and the second coil 72 of the first balun 7 at least partially overlap. The first conductor pattern portion P1 and the second conductor pattern portion P2 are, for example, spiral-shaped. The third coil 81 of the second balun 8 includes a third conductor pattern portion P3 that intersects (e.g., orthogonally) the thickness direction D1 of the mounting substrate 501. The fourth coil 82 of the second balun 8 includes a fourth conductor pattern portion P4 that intersects (e.g., orthogonally) the thickness direction D1 of the mounting substrate 501 and faces the third conductor pattern portion P3 in the thickness direction D1 of the mounting substrate 501. When viewed from above in the thickness direction D1 of the mounting substrate 501, the third coil 81 and the fourth coil 82 of the second balun 8 at least partially overlap. The third conductor pattern portion P3 and the fourth conductor pattern portion P4 are, for example, spiral-shaped.

[0116] (2.1.4) External connection terminals

[0117] Multiple external connection terminals T0 are disposed on the second main surface 512 of the mounting substrate 501. "External connection terminals T0 disposed on the second main surface 512 of the mounting substrate 501" includes the following situations: the external connection terminals T0 are mechanically connected to the second main surface 512 of the mounting substrate 501; and the external connection terminals T0 are electrically connected to (appropriate conductor portions) of the mounting substrate 501. The material of the multiple external connection terminals T0 is, for example, metal (e.g., copper, copper alloy, etc.). The multiple external connection terminals T0 are respectively columnar electrodes. The columnar electrodes are, for example, cylindrical electrodes. The multiple external connection terminals T0 are bonded to the conductor portions of the mounting substrate 501, for example, by solder, but not limited to this; for example, a conductive adhesive (e.g., conductive paste) may be used to bond to the conductor portions of the mounting substrate 501, or they may be directly bonded to the conductor portions of the mounting substrate 501. When viewed from the thickness direction D1 of the mounting substrate 501, the multiple external connection terminals T0 are each circular in shape.

[0118] Multiple external connection terminals T0 include a first antenna terminal T1, a second antenna terminal T2, a first signal input terminal T3, a second signal input terminal T4, a first signal output terminal T5, a second signal output terminal T6, a control terminal T7, and multiple ground terminals T8 (see reference). Figure 1 and Figure 3 (B). Multiple ground terminals T8 are terminals that are electrically connected to the ground electrode of the aforementioned circuit board of the communication device 600 and thus provided with ground potential.

[0119] (2.1.5) First resin layer

[0120] like Figure 3 A and Figure 3 As shown in Figure B, a first resin layer 520 is disposed on a first main surface 511 of a mounting substrate 501. The first resin layer 520 covers a plurality of electronic components mounted on the first main surface 511 of the mounting substrate 501. The first resin layer 520 comprises a resin (e.g., epoxy resin). The first resin layer 520 may also comprise fillers in addition to resin.

[0121] (2.1.6) Second resin layer

[0122] like Figure 3 A and Figure 3 As shown in Figure B, a second resin layer 540 is disposed on the second main surface 512 of the mounting substrate 501. The second resin layer 540 covers the outer peripheral surfaces of each of the plurality of electronic components mounted on the second main surface 512 of the mounting substrate 501, as well as the outer peripheral surfaces of each of the plurality of external connection terminals T0. Each outer peripheral surface of the plurality of electronic components includes four sides of the electronic component. The second resin layer 540 does not cover the main surface of each of the plurality of electronic components on the side opposite to the mounting substrate 501. The second resin layer 540 comprises resin (e.g., epoxy resin). The second resin layer 540 may also contain fillers in addition to resin. The material of the second resin layer 540 may be the same as or a different material from the material of the first resin layer 520.

[0123] (2.1.7) Metal electrode layer

[0124] like Figure 3 A and Figure 3As shown in B, the metal electrode layer 530 covers the first resin layer 520. The metal electrode layer 530 is connected to the ground terminal T8 of the mounting substrate 501. The metal electrode layer 530 is conductive. In the high-frequency module 500, the metal electrode layer 530 is a shielding layer provided for electromagnetic shielding of the inside and outside of the high-frequency module 500. The metal electrode layer 530 has a multilayer structure formed by stacking multiple metal layers, but is not limited to this, and may also be a single metal layer. The metal layer contains one or more metals. When the metal electrode layer 530 has a multilayer structure formed by stacking multiple metal layers, the metal electrode layer 530 includes, for example, a first stainless steel layer on the first resin layer 520, a Cu layer on the first stainless steel layer, and a second stainless steel layer on the Cu layer. The materials of the first stainless steel layer and the second stainless steel layer are respectively an alloy containing Fe, Ni, and Cr. Alternatively, when the metal electrode layer 530 is a single metal layer, the metal electrode layer 530 is, for example, a Cu layer. The metal electrode layer 530 covers the main surface 521 of the first resin layer 520 opposite to the mounting substrate 501 side, the outer peripheral surface 523 of the first resin layer 520, the outer peripheral surface 513 of the mounting substrate 501, and the outer peripheral surface 543 of the second resin layer 540. The main surface 541 of the second resin layer 540 opposite to the mounting substrate 501 side is exposed and not covered by the metal electrode layer 530. The metal electrode layer 530 is electrically connected to the ground plane of the mounting substrate 501. Therefore, the high-frequency module 500 can make the potential of the metal electrode layer 530 approximately the same as the potential of the ground plane of the mounting substrate 501.

[0125] (2.2) Layout in high-frequency modules

[0126] When viewed from the thickness direction D1 of the mounting substrate 501, at least a portion of the first balun 7 overlaps with the first switch 5 and the second switch 6, and at least a portion of the second balun 8 overlaps with the first switch 5 and the second switch 6. In the first balun 7, the first coil 71 and the second coil 72 face each other in the thickness direction D1 of the mounting substrate 501. In the second balun 8, the third coil 81 and the fourth coil 82 face each other in the thickness direction D1 of the mounting substrate 501.

[0127] (2.3) Summary

[0128] The high-frequency module 500 according to Embodiment 1 includes a high-frequency circuit 100 and a mounting substrate 501. The amplifier 3, first switch 5, second switch 6, first balun 7, and second balun 8 of the high-frequency circuit 100 are disposed on the mounting substrate 501. The high-frequency module 500 according to Embodiment 1 is capable of suppressing the degradation of the characteristics of the high-frequency circuit 100.

[0129] Furthermore, in the high-frequency module 500 according to Embodiment 1, the mounting substrate 501 has a first main surface 511 and a second main surface 512 facing each other. An amplifier 3 is disposed on the first main surface 511 of the mounting substrate 501. A first switch 5 and a second switch 6 are disposed on the second main surface 512 of the mounting substrate 501. A first balun 7 and a second balun 8 are disposed on the mounting substrate 501. When viewed from the thickness direction D1 of the mounting substrate 501, at least a portion of the first balun 7 overlaps with the first switch 5 and the second switch 6, and at least a portion of the second balun 8 overlaps with the first switch 5 and the second switch 6. In the high-frequency module 500 according to Embodiment 1, the degradation of the characteristics of the high-frequency circuit 100 can be further suppressed.

[0130] (3) Communication device

[0131] like Figure 1 As shown, the communication device 600 according to Embodiment 1 includes a signal processing circuit 601 and a high-frequency circuit 100. The signal processing circuit 601 is connected to the high-frequency circuit 100.

[0132] The communication device 600 also includes a first antenna A1 and a second antenna A2. The communication device 600 further includes a circuit board on which a high-frequency module 500 with high-frequency circuitry 100 is mounted. The circuit board is, for example, a printed circuit board. The circuit board includes a ground electrode to which a ground potential is provided.

[0133] The signal processing circuit 601 includes, for example, an RF signal processing circuit 602 and a baseband signal processing circuit 603. The RF signal processing circuit 602 is, for example, an RFIC (Radio Frequency Integrated Circuit) that processes high-frequency signals. The RF signal processing circuit 602 performs up-conversion and other signal processing on the high-frequency signal (transmit signal) output from the baseband signal processing circuit 603, and outputs the processed high-frequency signal. Additionally, the RF signal processing circuit 602 performs down-conversion and other signal processing on the high-frequency signal (receive signal) output from the high-frequency circuit 100, and outputs the processed high-frequency signal to the baseband signal processing circuit 603. The baseband signal processing circuit 603 is, for example, a BBIC (Baseband Integrated Circuit). The baseband signal processing circuit 603 generates I-phase and Q-phase signals based on the baseband signal. The baseband signal can be, for example, an externally input audio signal or image signal. The baseband signal processing circuit 603 performs IQ modulation processing by combining the I-phase and Q-phase signals, and then outputs the transmit signal. At this time, the transmitted signal is generated as a modulated signal (IQ signal) obtained by amplitude modulation of a carrier signal of a specified frequency with a period longer than the period of the carrier signal. The received signal, processed by the baseband signal processing circuit 603, is used, for example, as an image signal for image display, or as an audio signal for the user's conversation in the communication device 600. The high-frequency circuit 100 transmits high-frequency signals (received signal, transmitted signal) between the first antenna A1 and the second antenna A2 and the RF signal processing circuit 602 of the signal processing circuit 601.

[0134] The communication device 600 according to Embodiment 1 includes a high-frequency circuit 100 and a signal processing circuit 601, thus enabling the suppression of the degradation of the characteristics of the high-frequency circuit 100.

[0135] (Implementation Method 2)

[0136] Refer to each Figure 5 and 6 The high-frequency circuit 100a and high-frequency module 500a involved in Embodiment 2 will be described below. For the high-frequency circuit 100a and high-frequency module 500a involved in Embodiment 2, the same structural elements as those in the high-frequency circuit 100 and high-frequency module 500 involved in Embodiment 1 will be marked with the same reference numerals and their descriptions will be omitted.

[0137] In the high-frequency circuit 100a according to Embodiment 2, it differs from the high-frequency circuit 100 according to Embodiment 1 in the following aspects: the first power amplifier 31 includes an amplifier 3, a balun for impedance matching, and a capacitor C1. The balun for impedance matching of the first power amplifier 31 is shared with the first balun 7. In the high-frequency circuit 100a according to Embodiment 2, the amplifier 3, for example, has a driving stage transistor 301, a final stage (output stage) transistor 302, and an interstage matching circuit 303 for matching the impedance of the driving stage transistor 301 with the impedance of the final stage transistor 302. In the amplifier 3, the driving stage transistor 301 and the final stage transistor 302 are, for example, HBTs (Heterojunction Bipolar Transistors). The interstage matching circuit 303 is, for example, an inductor disposed between the driving stage transistor 301 and the final stage transistor 302, but it may also include a capacitor in addition to an inductor. The number of transistor stages in amplifier 3 is not limited to 2 stages; it can also be 1 stage or more than 3 stages. Amplifier 3 is, for example, a GaAs-based chip.

[0138] In the first power amplifier 31, the first terminal 711 of the first balun 7 is connected to the output terminal of the amplifier 3 (the collector terminal of the final stage transistor 302). The collector terminals of the driving stage transistor 301 and the final stage transistor 302 are supplied with a power supply voltage Vcc. A capacitor C1 is connected between the collector terminal of the final stage transistor 302 and ground.

[0139] Similar to the high-frequency circuit 100 in Embodiment 1, the high-frequency circuit 100a has a switch (first switch 5 and second switch 6) that is a nonlinear device connected between the first balun 7 and the second balun 8, thus suppressing the degradation of the characteristics of the high-frequency circuit 100a.

[0140] Furthermore, the high-frequency module 500a according to Embodiment 2 can suppress the degradation of the characteristics of the high-frequency circuit 100a. In addition, compared with the case where the first power amplifier 31 is separately provided as a balun and the first balun 7, the high-frequency module 500a according to Embodiment 2 can achieve miniaturization.

[0141] (Implementation Method 3)

[0142] Reference Figure 7The high-frequency circuit 100b and high-frequency module 500b involved in Embodiment 3 will be described below. For the high-frequency circuit 100b and high-frequency module 500b involved in Embodiment 3, the same structural elements as those in the high-frequency circuit 100 and high-frequency module 500 involved in Embodiment 1 will be marked with the same reference numerals and their descriptions will be omitted.

[0143] The circuit structure of the high-frequency circuit 100b in Embodiment 3 is the same as that of the high-frequency circuit 100 in Embodiment 1.

[0144] The high-frequency module 500b according to Embodiment 3 differs from the high-frequency module 500 according to Embodiment 1 in that the second balun 8 is not built into the mounting substrate 501. In the high-frequency module 500b, one of the plurality of electronic components mounted on the first main surface 511 of the mounting substrate 501 (hereinafter also referred to as electronic component E1) includes a first transmit filter 11 (first filter 1) and a second balun 8. Electronic component E1 is a longitudinally coupled SAW filter including the first transmit filter 11 and the second balun 8.

[0145] Similar to the high-frequency circuit 100 in Embodiment 1, the high-frequency circuit 100b has a switch (first switch 5 and second switch 6) that is a nonlinear device connected between the first balun 7 and the second balun 8, thus suppressing the degradation of the characteristics of the high-frequency circuit 100b.

[0146] In addition, the high-frequency module 500b includes a high-frequency circuit 100b and a mounting substrate 501, thus suppressing the degradation of the characteristics of the high-frequency circuit 100b.

[0147] (Implementation Method 4)

[0148] Reference Figures 8-10 The high-frequency circuit 100c and high-frequency module 500c involved in Embodiment 4 will be described below. Regarding the high-frequency circuit 100c and high-frequency module 500c involved in Embodiment 4, structural elements that are the same as those in the high-frequency circuit 100 and high-frequency module 500 involved in Embodiment 1 will be marked with the same reference numerals and descriptions will be omitted as appropriate.

[0149] The high-frequency circuit 100c according to Embodiment 4 differs from the high-frequency circuit 100 according to Embodiment 1 in the following aspects: such as Figure 8As shown, a first filter 1A (first transmit filter 11A) having a first passband and a second filter 1B (second transmit filter 11B) having the same second passband as the first passband are provided to replace one filter 1. The first passband of the first filter 1A and the second passband of the second filter 1B include the uplink band of the first communication frequency band. In the second balun 8 in the high-frequency circuit 100c, the first terminal 811 of the third coil 81 is connected to the first terminal 721 of the second coil 72 via the first filter 1A and the first switch 5, and the second terminal 822 of the third coil 81 is connected to the second terminal 722 of the second coil 72 via the second filter 1B and the second switch 6. In the second balun 8, the first terminal 821 of the fourth coil 82 is connected to the signal path S1, and the second terminal 822 of the fourth coil 82 is connected to ground. The first terminal 821 of the fourth coil 82 of the second balun 8 is connected to the second terminal 111 of the third switch 10.

[0150] In the high-frequency circuit 100c, the first filter 1A (first transmitting filter 11A) is connected between the first switch 5 (selection terminal 51) and the first end 811 of the third coil 81 of the second balun 8, and the second filter 1B (second transmitting filter 11B) is connected between the second switch 6 (selection terminal 61) and the second end 812 of the third coil 81 of the second balun 8.

[0151] The high-frequency circuit 100c according to Embodiment 4 includes a first filter 1A, a second filter 1B, an amplifier 3, a first switch 5, a second switch 6, a first balun 7, and a second balun 8. The first filter 1A has a first passband. The second filter 1B has a second passband identical to the first passband. The amplifier 3 has an input terminal and an output terminal. The amplifier 3 is connected to the filter 1. The first balun 7 has a first coil 71 and a second coil 72. The second balun 8 has a third coil 81 and a fourth coil 82. In the first balun 7, the first end 711 of the first coil 71 is connected to the output terminal of the amplifier 3, and the second end 712 of the first coil 71 is connected to ground. In the first balun 7, the first end 721 of the second coil 72 is connected to the first switch 5, and the second end 722 of the second coil 72 is connected to the second switch 6. In the second balun 8, the first end 811 of the third coil 81 is connected to the first end 721 of the second coil 72 via the first filter 1A and the first switch 5, and the second end 822 of the third coil 81 is connected to the second end 722 of the second coil 72 via the second filter 1B and the second switch 6. In the second balun 8, the first end 821 of the fourth coil 82 is connected to the signal path S1, and the second end 822 of the fourth coil 82 is connected to ground.

[0152] The high-frequency circuit 100c according to Embodiment 4 can suppress the degradation of its characteristics. More specifically, in the high-frequency circuit 100c, switches (first switch 5 and second switch 6), which are nonlinear devices, are connected between the first balun 7 and the second balun 8, thus reducing the power applied to the switches (first switch 5 and second switch 6). Therefore, the high-frequency circuit 100c can reduce signal distortion of the high-frequency signal at the switches (first switch 5 and second switch 6), and suppress the degradation of its characteristics. Furthermore, in the high-frequency circuit 100c according to Embodiment 4, filters (first filter 1A and second filter 1B), which are nonlinear devices, are connected between the first balun 7 and the second balun 8, thus reducing the power applied to the filters (each of the first filter 1A and second filter 1B). Therefore, the high-frequency circuit 100c can reduce signal distortion of the high-frequency signal at the filters (each of the first filter 1A and second filter 1B), and suppress the degradation of its characteristics. Furthermore, the high-frequency circuit 100c according to Embodiment 4 includes a first balun 7 and a second balun 8, thus enabling the suppression of temperature rise in each of the switches (first switch 5 and second switch 6) and filters (first filter 1A and second filter 1B).

[0153] Furthermore, in the high-frequency circuit 100c, amplifier 3 is a power amplifier 31 that amplifies the transmitted signal. The first balun 7 is connected to the output terminal of amplifier 3. Therefore, the high-frequency circuit 100c can suppress signal distortion of the transmitted signal.

[0154] In addition, the high-frequency circuit 100c also includes: a transmitting filter 12 (see reference). Figure 1 ); and the second amplifier 4 (refer to) Figure 1 This is an amplifier other than the first amplifier 3, which is an amplifier 3, and has input and output terminals, and is connected to the transmitting filter 12 (see reference 12). Figure 1 (Connection). In the high-frequency circuit 100c, the transmitting filter 12 constitutes a third filter having a third passband different from the first passband of the first filter 1. The first passband includes the uplink band of the first communication frequency band. The third passband includes the uplink band of the third communication frequency band. The first communication frequency band is, for example, Band 25 of the 3GPP LTE standard. The third communication frequency band is, for example, Band 66 of the 3GPP LTE standard.

[0155] Therefore, the high-frequency circuit 100c can, for example, reduce the size of the IMD that occurs when performing dual uplink carrier aggregation using the first amplifier 3 (first power amplifier 31) and the second amplifier 4 (second power amplifier 32).

[0156] like Figure 9 and 10 As shown, the high-frequency module 500c according to Embodiment 4 includes a high-frequency circuit 100c and a mounting substrate 501.

[0157] In the high-frequency module 500c, the first switch 5 and the second switch 6 are mounted on the first main surface 511 of the mounting substrate 501. Additionally, in the high-frequency module 500c, one of the plurality of electronic components mounted on the first main surface 511 of the mounting substrate 501 (hereinafter also referred to as electronic component E2) includes a first filter 1A and a second filter 1B. In electronic component E2, the first filter 1A and the second filter 1B share a common piezoelectric substrate. The piezoelectric substrate is, for example, a piezoelectric substrate, but is not limited thereto.

[0158] The high-frequency module 500c includes a high-frequency circuit 100c and a mounting substrate 501, thus enabling it to suppress the degradation of the characteristics of the high-frequency circuit 100c.

[0159] (Implementation Method 5)

[0160] Reference Figure 11The high-frequency circuit 100d and high-frequency module 500d involved in Embodiment 5 will be described below. For the high-frequency circuit 100d and high-frequency module 500d involved in Embodiment 5, the same structural elements as those in the high-frequency circuit 100c and high-frequency module 500c involved in Embodiment 4 will be marked with the same reference numerals and descriptions will be omitted as appropriate.

[0161] The high-frequency circuit 100d according to Embodiment 5 differs from the high-frequency circuit 100c according to Embodiment 4 in that it also includes a third balun 9 and a fourth balun 17. Furthermore, the high-frequency circuit 100d differs from the high-frequency circuit 100c according to Embodiment 4 in that it includes a third filter 2A (third transmit filter 12A) and a fourth filter 2B (fourth transmit filter 12B) instead of the transmit filter 12. The third passband of the third filter 2A and the fourth passband of the fourth filter 2B include the uplink band of the second communication frequency band. The third balun 9 has a fifth coil 91 and a sixth coil 92. In the third balun 9, the first end 911 of the fifth coil 91 is connected to the output terminal of the second amplifier 4 (second power amplifier 32), and the second end 912 of the fifth coil 91 is connected to ground. In the third balun 9, the first end 921 of the sixth coil 92 is connected to the third filter 2A via the first switch 5, and the second end 922 of the sixth coil 92 is connected to the fourth filter 2B via the second switch 6. The fourth balun 17 has a seventh coil 171 and an eighth coil 172.

[0162] In the high-frequency circuit 100d, the first switch 5 also has a common terminal 50B. Additionally, in the high-frequency circuit 100d, the second switch 6 also has a common terminal 60B. In the high-frequency circuit 100d, the common terminal 50 of the first switch 5 is connected to the first end 721 of the second coil 72 of the first balun 7, and the common terminal 50B of the first switch 5 is connected to the first end 921 of the sixth coil 92 of the third balun 9. Furthermore, in the high-frequency circuit 100d, the common terminal 60 of the second switch 6 is connected to the second end 722 of the second coil 72 of the first balun 7, and the common terminal 60B of the second switch 6 is connected to the second end 922 of the sixth coil 92 of the third balun 9.

[0163] In the high-frequency circuit 100d, the first end 811 of the third coil 81 of the second balun 8 is connected to the selection terminal 51 of the first switch 5 via the first filter 1A, and the second end 812 of the third coil 81 of the second balun 8 is connected to the selection terminal 61 of the second switch 6 via the second filter 1B. Additionally, in the high-frequency circuit 100d, the first end 821 of the fourth coil 82 of the second balun 8 is connected to the second terminal 111 of the third switch 10, and the second end 822 of the fourth coil 82 of the second balun 8 is connected to ground. Furthermore, in the high-frequency circuit 100d, the first end 1711 of the seventh coil 171 of the fourth balun 17 is connected to the selection terminal 52 of the first switch 5 via the third filter 2A, and the second end 1712 of the seventh coil 171 of the fourth balun 17 is connected to the selection terminal 62 of the second switch 6 via the fourth filter 2B. In addition, in the high-frequency circuit 100d, the first end 1721 of the eighth coil 172 of the fourth balun 17 is connected to the second terminal 112 of the third switch 10, and the second end 1722 of the eighth coil 172 of the fourth balun 17 is connected to ground.

[0164] Like the high-frequency circuit 100c in Embodiment 4, the high-frequency circuit 100d in Embodiment 5 can suppress the degradation of its characteristics. Furthermore, in the high-frequency circuit 100d, filters (third filter 2A and fourth filter 2B), which are nonlinear devices, are connected between the third balun 9 and the fourth balun 17, thus reducing the power applied to the filters (each of the third filter 2A and the fourth filter 2B). Therefore, the high-frequency circuit 100d can reduce signal distortion of the high-frequency signals at the filters (each of the third filter 2A and the fourth filter 2B), and suppress the degradation of its characteristics.

[0165] In addition, the high-frequency circuit 100d can, for example, reduce the size of the IMD that occurs when performing dual uplink carrier aggregation using the first amplifier 3 (first power amplifier 31) and the second amplifier 4 (second power amplifier 32).

[0166] The high-frequency module 500d includes a high-frequency circuit 100d and a mounting substrate 501 (see reference). Figure 9 Therefore, it can suppress the degradation of the characteristics of the high-frequency circuit 100d.

[0167] (Implementation Method 6)

[0168] Reference Figure 12The high-frequency circuit 100e and high-frequency module 500e involved in Embodiment 6 will be described below. Regarding the high-frequency circuit 100e and high-frequency module 500e involved in Embodiment 6, structural elements that are the same as those in the high-frequency circuit 100d and high-frequency module 500d involved in Embodiment 5 will be marked with the same reference numerals and descriptions will be omitted as appropriate.

[0169] The high-frequency circuit 100e differs from the high-frequency circuit 100d according to Embodiment 5 in that the first filter 1A and the second filter 1B are connected to the second balun 8 via a third switch 10. Furthermore, the high-frequency circuit 100e differs from the high-frequency circuit 100d according to Embodiment 5 in that the third switch 10 also has first terminals 103 and 104, and second terminals 113 and 114. In the third switch 10, the first terminals 101, 102, 103, and 104 can be connected to the second terminals 111, 112, 113, and 114, respectively. Additionally, the high-frequency circuit 100e differs from the high-frequency circuit 100d according to Embodiment 5 in that the third filter 2A and the fourth filter 2B are connected to the fourth balun 17 via the third switch 10.

[0170] In the third switch 10, the second terminal 111 is connected to the selection terminal 51 of the first switch 5 via the first filter 1A, and the first terminal 101 is connected to the first end 811 of the third coil 81 of the second balun 8. Additionally, in the third switch 10, the second terminal 112 is connected to the selection terminal 61 of the second switch 6 via the second filter 1B. Furthermore, in the third switch 10, the second terminal 113 is connected to the selection terminal 52 of the first switch 5 via the third filter 2A, and the first terminal 103 is connected to the first end 1711 of the seventh coil 171 of the fourth balun 17. Additionally, in the third switch 10, the second terminal 114 is connected to the selection terminal 62 of the second switch 6 via the fourth filter 2B, and the first terminal 104 is connected to the second end 1712 of the seventh coil 171 of the fourth balun 17.

[0171] In the high-frequency circuit 100e, the first terminal 821 of the fourth coil 82 of the second balun 8 is connected to the antenna terminal T1, and the second terminal 822 of the fourth coil 82 of the second balun 8 is connected to ground. Additionally, in the high-frequency circuit 100e, the first terminal 1721 of the eighth coil 172 of the fourth balun 17 is connected to the antenna terminal T2, and the second terminal 1722 of the eighth coil 172 of the fourth balun 17 is connected to ground.

[0172] Like the high-frequency circuit 100d in Embodiment 5, the high-frequency circuit 100e in Embodiment 6 can suppress the degradation of the characteristics of the high-frequency circuit 100e. Furthermore, in the high-frequency circuit 100e in Embodiment 6, the third switch 10, which is a nonlinear device, is connected between the first balun 7 and the second balun 8, thus reducing the power applied to the third switch 10. Therefore, the high-frequency circuit 100d can reduce signal distortion of the high-frequency signal at the third switch 10 and suppress the degradation of the characteristics of the high-frequency circuit 100e.

[0173] The high-frequency circuit 100e, for example, can reduce the size of the IMD that occurs when performing dual uplink carrier aggregation using the first amplifier 3 (first power amplifier 31) and the second amplifier 4 (second power amplifier 32).

[0174] In addition, the high-frequency module 500e includes a high-frequency circuit 100e and a mounting substrate 501 (see reference). Figure 9 Therefore, it can suppress the degradation of the characteristics of the high-frequency circuit 100e.

[0175] (Implementation Method 7)

[0176] Reference Figure 13 The high-frequency circuit 100f and high-frequency module 500f according to Embodiment 7 will be described below. Regarding the high-frequency circuit 100f and high-frequency module 500f according to Embodiment 7, compared with the high-frequency circuit 100c according to Embodiment 4 (see...), Figure 8 The same structural elements as the high-frequency module 500c are marked with the same label and the description is omitted appropriately.

[0177] The high-frequency circuit 100f according to Embodiment 7 differs from the high-frequency circuit 100c according to Embodiment 4 in that it also includes a filter 1 connected between the first end 821 of the fourth coil 82 of the second balun 8 and the third switch 10.

[0178] The passband of filter 1 is the same as the first passband of the first filter 1A.

[0179] In Embodiment 7, the high-frequency circuit 100f is similar to that in Embodiment 4, where switches (first switch 5 and second switch 6) are connected between the first balun 7 and the second balun 8, thus suppressing the degradation of the characteristics of the high-frequency circuit 100f. Furthermore, in Embodiment 7, the high-frequency circuit 100f is similar to that in Embodiment 4, where filters (first filter 1A and second filter 1B) are connected between the first balun 7 and the second balun 8, thus suppressing the degradation of the characteristics of the high-frequency circuit 100f.

[0180] In addition, the high-frequency circuit 100f according to embodiment 7 also includes a filter 1, which can improve the attenuation characteristics.

[0181] In addition, the high-frequency module 500f includes a high-frequency circuit 100f and a mounting substrate 501 (see reference). Figure 9 Therefore, it can suppress the degradation of the characteristics of the high-frequency circuit 100f.

[0182] (Implementation Method 8)

[0183] Reference Figure 14 The high-frequency circuit 100g and high-frequency module 500g involved in Embodiment 8 will be described below. Regarding the high-frequency circuit 100g and high-frequency module 500g involved in Embodiment 8, compared with the high-frequency circuit 100c involved in Embodiment 4 (see...), Figure 8 The same structural elements as the high-frequency module 500c are marked with the same label and the description is omitted appropriately.

[0184] The high-frequency circuit 100g differs from the high-frequency circuit 100c according to Embodiment 4 in that it also includes a third balun 9 and a third filter 1C. The third balun 9 has a fifth coil 91 and a sixth coil 92. In the third balun 9, the first end 911 of the fifth coil 91 is connected to the selection terminal 53 of the first switch 5, and the second end 912 of the fifth coil 91 is connected to the selection terminal 63 of the second switch 6. In the third balun 9, the first end 921 of the sixth coil 92 is connected to the second terminal 112 of the third switch 10 via the third filter 1C, and the second end 922 of the sixth coil 92 is connected to ground. In the third switch 10, the first terminal 101 is connected to at least one of the two second terminals 111 and 112.

[0185] In the high-frequency circuit 100g according to Embodiment 8, similarly to the high-frequency circuit 100c according to Embodiment 4, switches (first switch 5 and second switch 6) are connected between the first balun 7 and the second balun 8, thus suppressing the degradation of the characteristics of the high-frequency circuit 100g. Furthermore, in the high-frequency circuit 100g according to Embodiment 8, similarly to the high-frequency circuit 100c according to Embodiment 4, filters (first filter 1A and second filter 1B) are connected between the first balun 7 and the second balun 8, thus suppressing the degradation of the characteristics of the high-frequency circuit 100g.

[0186] In addition, the high-frequency module 500g includes a high-frequency circuit 100g and a mounting substrate 501 (see reference). Figure 9 Therefore, it can suppress the degradation of the characteristics of high-frequency circuits by 100g.

[0187] (Implementation Method 9)

[0188] Reference Figure 15 The high-frequency circuit 100h and high-frequency module 500h according to Embodiment 9 will be explained below. Regarding the high-frequency circuit 100h and high-frequency module 500h according to Embodiment 9, compared with the high-frequency circuit 100c according to Embodiment 4 (see...), Figure 8 The same structural elements as the high-frequency module 500c are marked with the same label and the description is omitted appropriately.

[0189] The high-frequency circuit 100h differs from the high-frequency circuit 100c according to Embodiment 4 in that it also includes a third balun 9. Furthermore, the high-frequency circuit 100h differs from the high-frequency circuit 100c according to Embodiment 4 in that the first switch 5 also has an additional common terminal 50B besides the common terminal 50, and the second switch 6 also has an additional common terminal 60B besides the common terminal 60.

[0190] The third balun 9 has a fifth coil 91 and a sixth coil 92. In the third balun 9, the first end 911 of the fifth coil 91 is connected to the input terminal of the low-noise amplifier 41, and the second end 912 of the fifth coil 91 is connected to ground. In the third balun 9, the first end 921 of the sixth coil 92 is connected to the common terminal 50B of the first switch 5, and the second end 922 of the sixth coil 92 is connected to the common terminal 60B of the second switch 6.

[0191] In the first switch 5, common terminal 50 and common terminal 50B can be connected to select terminal 51 respectively. The first switch 5 is a switch that can connect at least one of the three select terminals 51 to 53 to each of the common terminals of common terminal 50 and common terminal 50B.

[0192] In the high-frequency circuit 100h, the passband of filter 1 includes the frequency band of the first communication band used in communication supporting the TDD (Time Division Duplex) communication mode. The high-frequency circuit 100h can, for example, simulate the simultaneous transmission and reception of the transmit signal and receive signal of the first communication band using TDD. "Simulatedly implemented" means that although the transmission of the transmit signal and the reception of the receive signal are not simultaneous, they occur within a short period of time that can be considered simultaneous. The first communication band is, for example, Band 34 of the 3GPP LTE standard, but is not limited to this; it could also be, for example, Band 39 of the 3GPP LTE standard.

[0193] When the high-frequency circuit 100h transmits a signal in the first communication frequency band using TDD communication, the common terminal 50 of the first switch 5 is connected to the selection terminal 51, and the common terminal 60 of the second switch 6 is connected to the selection terminal 61. Furthermore, when the high-frequency circuit 100h receives a signal in the first communication frequency band using TDD communication, the common terminal 50B of the first switch 5 is connected to the selection terminal 51, and the common terminal 60B of the second switch 6 is connected to the selection terminal 61.

[0194] In the high-frequency circuit 100h according to Embodiment 9, the switches (first switch 5 and second switch 6) and filters (first filter 1A and second filter 1B) are connected between the first balun 7 and the second balun 8, thus suppressing the degradation of the characteristics of the high-frequency circuit 100h. Furthermore, in the high-frequency circuit 100h according to Embodiment 9, the switches (first switch 5 and second switch 6) and filters (first filter 1A and second filter 1B) are connected between the third balun 9 and the second balun 8, thus suppressing the degradation of the characteristics of the high-frequency circuit 100h. More specifically, the high-frequency circuit 100h can suppress signal distortion of both the transmitted and received signals during TDD-based communication, thereby suppressing the degradation of the characteristics of the high-frequency circuit 100h.

[0195] In addition, the high-frequency module 500h includes a high-frequency circuit 100h and a mounting substrate 501 (see reference). Figure 9 Therefore, it can suppress the degradation of the characteristics of high-frequency circuits for 100 hours.

[0196] (Implementation Method 10)

[0197] Reference Figure 16The high-frequency circuit 100i and high-frequency module 500i involved in Embodiment 10 will be described below. Regarding the high-frequency circuit 100i and high-frequency module 500i involved in Embodiment 10, compared with the high-frequency circuit 100 involved in Embodiment 1 (refer to...),... Figure 1 and 2 The structural elements of the high-frequency module 500 are the same as those of the high-frequency module 500, and are marked with the same label with appropriate omissions of description.

[0198] The high-frequency circuit 100i differs from the high-frequency circuit 100 according to Embodiment 1 in that it also includes a switch 19. The switch 19 has a first terminal 191 and a second terminal 192 that can be connected to the first terminal 191. In the switch 19, the first terminal 191 is connected to the node between the first end 821 of the fourth coil 82 of the second balun 8 and the filter 1. Additionally, in the switch 19, the second terminal 192 is connected to the input terminal of the low-noise amplifier 41.

[0199] In the high-frequency circuit 100i, the passband of filter 1 includes the frequency band of the first communication frequency band used in communication supporting the TDD communication method. The high-frequency circuit 100i can, for example, simulate the simultaneous transmission and reception of the transmit signal and receive signal of the first communication frequency band using TDD. The first communication frequency band is, for example, Band 34 of the 3GPP LTE standard, but is not limited to this; it could also be, for example, Band 39 of the 3GPP LTE standard.

[0200] When the high-frequency circuit 100i transmits a signal in the first communication band using TDD communication, the common terminal 50 of the first switch 5 is connected only to the selection terminal 51 among the multiple selection terminals 51 to 53, and the common terminal 60 of the second switch 6 is connected only to the selection terminal 61 among the multiple selection terminals 61 to 63, while the first terminal 191 of the switch 19 is not connected to the second terminal 192. Furthermore, when the high-frequency circuit 100i receives a signal in the first communication band using TDD communication, the first terminal 191 of the switch 19 is connected to the second terminal 192, and the common terminal 50 of the first switch 5 is not connected to any of the multiple selection terminals 51 to 53, and the common terminal 60 of the second switch 6 is not connected to any of the multiple selection terminals 61 to 63.

[0201] In the high-frequency circuit 100i according to embodiment 10, switches (first switch 5 and second switch 6) are connected between the first balun 7 and the second balun 8, thus suppressing the degradation of the characteristics of the high-frequency circuit 100i. More specifically, the high-frequency circuit 100i can suppress signal distortion of the transmitted signal during TDD-based communication, thereby suppressing the degradation of the characteristics of the high-frequency circuit 100i.

[0202] In addition, the high-frequency module 500i includes a high-frequency circuit 100i and a mounting substrate 501 (see reference). Figure 3 A and Figure 3 (B), thus it is able to suppress the degradation of the characteristics of the high-frequency circuit 100i.

[0203] (Implementation Method 11)

[0204] Reference Figure 17 The high-frequency circuit 100j and high-frequency module 500j involved in Embodiment 11 will be described below. Regarding the high-frequency circuit 100j and high-frequency module 500j involved in Embodiment 11, compared with the high-frequency circuit 100c involved in Embodiment 4 (see...), Figure 8 The same structural elements as the high-frequency module 500c are marked with the same label and the description is omitted appropriately.

[0205] The high-frequency circuit 100j differs from the high-frequency circuit 100c of embodiment 4 in that it also includes a switch 18 and a transmitting filter 11C.

[0206] Switch 18 is connected between the output terminal of amplifier 3 (power amplifier 31) and the first balun 7. In the high-frequency circuit 100j according to embodiment 11, switch 18 constitutes a fourth switch connected between the output terminal of amplifier 3 and the first balun 7. Switch 18 has a common terminal 180 and a plurality of (e.g., 2) select terminals 181, 182. The common terminal 180 is connected to the output terminal of amplifier 3. Select terminal 181 is connected to the first end 711 of the first coil 71 in the first balun 7. Select terminal 182 is connected to the third switch 10 via a transmit filter 11C, not via the first balun 7 and the second balun 8. The transmit filter 11C is provided in the signal path (bypass path) S2 between the select terminal 182 of switch 18 and the third switch 10. Switch 18 is a switch capable of selectively connecting one of the plurality of select terminals 181, 182 to the common terminal 180. Switch 18, for example, is derived from signal processing circuit 601 (see reference). Figure 1 The switch 18 is controlled by the RF signal processing circuit 602 from the signal processing circuit 601. The switch 18 switches the connection state between the common terminal 180 and the two selection terminals 181 and 182 according to the control signal from the RF signal processing circuit 602. The switch 18 is, for example, a switch IC.

[0207] The transmitting filter 11C has the same passband as the first filter 1.

[0208] In the high-frequency circuit 100j, amplifier 3 can operate in a first power mode (e.g., high power mode) and a second power mode (e.g., low power mode) where the output power is lower than that of the first power mode. In high power mode, amplifier 3 sets its output power to a first predetermined power (e.g., 32 dBm). In low power mode, amplifier 3 sets its output power to a second predetermined power (e.g., 15 dBm) lower than the first predetermined power.

[0209] The controller 13 causes the amplifier 3 to operate in either a first power mode or a second power mode according to the control signal from the signal processing circuit 601.

[0210] In the high-frequency circuit 100j, when the controller 13 operates the amplifier 3 in the first power mode, the switch 18 makes the output terminal of the amplifier 3 connected to the first balun 7 and deconnects the output terminal of the amplifier 3 from the transmitting filter 11C. More specifically, when the controller 13 operates the amplifier 3 in the first power mode, in the switch 18, the common terminal 180 is connected to one of the two selection terminals 181 and 182, which is the selection terminal 181.

[0211] In the high-frequency circuit 100j, when the controller 13 operates the amplifier 3 in the second power mode, the switch 18 de-connects the output terminal of the amplifier 3 with the first balun 7 and connects the output terminal of the amplifier 3 with the transmit filter 11C. More specifically, when the controller 13 operates the amplifier 3 in the second power mode, in the switch 18, the common terminal 180 is connected to one of the two select terminals 181 and 182, select terminal 182. Thus, the amplifier 3 is connected to the third switch 10 via the transmit filter 11C, not via the first balun 7 and the second balun 8.

[0212] In the high-frequency circuit 100j according to Embodiment 11, switches (first switch 5 and second switch 6), which are nonlinear devices, are connected between the first balun 7 and the second balun 8, thus reducing the power applied to the switches (first switch 5 and second switch 6). Therefore, the high-frequency circuit 100j can reduce signal distortion of the high-frequency signals at the switches (first switch 5 and second switch 6) when the amplifier 3 operates in the first power mode, and can suppress the degradation of the characteristics of the high-frequency circuit 100j. Furthermore, in the high-frequency circuit 100j according to Embodiment 11, filters (first filter 1A and second filter 1B), which are nonlinear devices, are connected between the first balun 7 and the second balun 8, thus reducing the power applied to the filters (each of the first filter 1A and second filter 1B). Therefore, the high-frequency circuit 100j can reduce signal distortion of the high-frequency signals at the filters (each of the first filter 1A and second filter 1B) when the amplifier 3 operates in the first power mode, and can suppress the degradation of the characteristics of the high-frequency circuit 100j.

[0213] In addition, the high-frequency circuit 100j can, for example, reduce the size of the IMD that occurs when the first amplifier 3 operates in the first power mode and performs dual uplink carrier aggregation utilizing the first amplifier 3 (first power amplifier 31) and the second amplifier 4 (second power amplifier 32).

[0214] In addition, the high-frequency module 500j includes a high-frequency circuit 100j and a mounting substrate 501 (see reference). Figure 9 Therefore, it can suppress the degradation of the characteristics of the high-frequency circuit 100j.

[0215] (Implementation Method 12)

[0216] Reference Figure 18 This section will explain the high-frequency circuit 100k and high-frequency module 500k involved in Embodiment 12. Regarding the high-frequency circuit 100k and high-frequency module 500k involved in Embodiment 12, compared with the high-frequency circuit 100c involved in Embodiment 4 (see...),... Figure 8 The same structural elements as the high-frequency module 500c are marked with the same label and the description is omitted appropriately.

[0217] The high-frequency circuit 100k differs from the high-frequency circuit 100c of embodiment 4 in that it also includes a switch 18.

[0218] Switch 18 is connected between the input terminal of the first amplifier 3 (first power amplifier 31) and the signal input terminal T3. Switch 18 has a common terminal 180 and multiple (e.g., two) selectable terminals 181 and 182. The common terminal 180 is connected to the signal input terminal T3. Selectable terminal 181 is connected to the input terminal of the first amplifier 3 (first power amplifier 31). Selectable terminal 182 is connected to the input terminal of the second amplifier 4 (second power amplifier 32). The output terminal of the second amplifier 4 is connected to the third switch 10 via a transmit filter 12C, not via the first balun 7 and the second balun 8. The transmit filter 12C is provided in the signal path (bypass path) S2 between the output terminal of the second amplifier 4 and the second terminal 112 of the third switch 10. Switch 18 is a switch capable of selectively connecting one of the multiple selectable terminals 181 and 182 to the common terminal 180. Switch 18 is provided, for example, by a communication device 600 (see reference 600). Figure 1 The switch 18 is controlled by the signal processing circuit 601. The switch 18 switches the connection state between the common terminal 180 and the two selection terminals 181 and 182 according to the control signal from the RF signal processing circuit 602 of the signal processing circuit 601. The switch 18 is, for example, a switch IC.

[0219] The first power amplifier 31 and the second power amplifier 32 support different power levels. "Power level" is a classification of the output power of the terminal (communication device 600) defined by maximum output power, etc. (User Equipment Power Class). The smaller the number following "power level," the higher the supported output power. For example, the maximum output power of power level 1 (29 dBm) is greater than that of power level 2 (26 dBm), and the maximum output power of power level 2 (26 dBm) is greater than that of power level 3 (23 dBm). The maximum output power is determined, for example, by methods specified by 3GPP, etc. The first power amplifier 31 supports a first power level (e.g., power level 2), and the second power amplifier 32 supports a second power level (e.g., power level 3) with a maximum output power lower than that of the first power level. In the high-frequency circuit 100k, the controller 13 controls the first power amplifier 31 and the second power amplifier 32, for example, according to a control signal from the signal processing circuit 601.

[0220] In the high-frequency circuit 100k, the first passband and second passband of each of the first filter 1A and the second filter 1B through which the transmit signal from the first amplifier 3 supporting a first power level (e.g., power level 2) passes are included in the frequency band of the first communication band used in communication supporting TDD. The high-frequency circuit 100k can, for example, simulate the simultaneous transmission and reception of the transmit signal and the receive signal of the first communication band using TDD. The first communication band is, for example, Band 41 of the 3GPP LTE standard or n41 of 5G NR, but is not limited thereto; for example, it could also be Band 40 of the 3GPP LTE standard or n40 of 5G NR. Furthermore, in the high-frequency circuit 100k, the passband of the transmit filter 12C through which the transmit signal from the second amplifier 4 supporting a second power level (e.g., power level 3) passes is included in the uplink frequency band of the second communication band used in communication supporting FDD (Frequency Division Duplex). The second communication frequency band is, for example, Band 7 of the 3GPP LTE standard or n7 of 5G NR, but is not limited to these.

[0221] In the high-frequency circuit 100k according to Embodiment 12, switches (first switch 5 and second switch 6), which are nonlinear devices, are connected between the first balun 7 and the second balun 8, thus reducing the power applied to the switches (first switch 5 and second switch 6). Therefore, the high-frequency circuit 100k can reduce signal distortion of the high-frequency signal at the switches (first switch 5 and second switch 6) when the first amplifier 3 of the first power level is operating, and can suppress the degradation of the characteristics of the high-frequency circuit 100k. Furthermore, in the high-frequency circuit 100k according to Embodiment 12, filters (first filter 1A and second filter 1B), which are nonlinear devices, are connected between the first balun 7 and the second balun 8, thus reducing the power applied to the filters (each of the first filter 1A and second filter 1B). Therefore, the high-frequency circuit 100k can reduce signal distortion of the high-frequency signal at the filters (each of the first filter 1A and second filter 1B) when the first amplifier 3 is operating, and can suppress the degradation of the characteristics of the high-frequency circuit 100k.

[0222] In addition, the high-frequency module 500k includes a high-frequency circuit 100k and a mounting substrate 501 (see reference). Figure 9 Therefore, it can suppress the degradation of the characteristics of high-frequency circuits at 100kHz.

[0223] (Implementation Method 13)

[0224] Reference Figure 19The high-frequency circuit 100m and high-frequency module 500m involved in Embodiment 13 will be explained below. Regarding the high-frequency circuit 100m and high-frequency module 500m involved in Embodiment 13, compared with the high-frequency circuit 100 involved in Embodiment 1 (refer to...), Figure 1 and 2 The structural elements of the high-frequency module 500 are the same as those of the high-frequency module 500, and are marked with the same label with appropriate omissions of description.

[0225] The high-frequency circuit 100m according to Embodiment 13 includes a filter 1 (receiving filter 21), an amplifier 3 (low-noise amplifier 41), a first switch 5, a second switch 6, a first balun 7, and a second balun 8. The filter 1 has a passband. The amplifier 3 has an input terminal and an output terminal. The amplifier 3 is connected to the filter 1. The first balun 7 has a first coil 71 and a second coil 72. The second balun 8 has a third coil 81 and a fourth coil 82. In the first balun 7, the first end 711 of the first coil 71 is connected to the input terminal of the amplifier 3, and the second end 712 of the first coil 71 is connected to ground. In the first balun 7, the first end 721 of the second coil 72 is connected to the first switch 5, and the second end 722 of the second coil 72 is connected to the second switch 6. In the second balun 8, the first end 811 of the third coil 81 is connected to the first end 721 of the second coil 72 via the first switch 5, and the second end 812 of the third coil 81 is connected to the second end 722 of the second coil 72 via the second switch 6. In the second balun 8, the first end 821 of the fourth coil 82 is connected to the filter 1, and the second end 822 of the fourth coil 82 is connected to ground.

[0226] In addition, the high-frequency circuit 100m also includes an antenna terminal T1 and a third switch 10 connected between the antenna terminal T1 and the second balun 8. The third switch 10 is configured to connect the first filter 1 to the first antenna terminal T1. The third switch 10 has a first terminal 101 and a second terminal 111 that can be connected to the first terminal 101. In the third switch 10, the first terminal 101 is connected to the antenna terminal T1, and the second terminal 111 is connected to the input terminal of the filter 1. Furthermore, in the high-frequency circuit 100m, the output terminal of the amplifier 3 (low-noise amplifier 41) is connected to the first signal output terminal T5.

[0227] The high-frequency circuit 100m according to Embodiment 13 can suppress the degradation of its characteristics. More specifically, in the high-frequency circuit 100m, switches (first switch 5 and second switch 6), which are nonlinear devices, are connected between the first balun 7 and the second balun 8, thus reducing the power applied to the switches (first switch 5 and second switch 6). As a result, the high-frequency circuit 100m can reduce signal distortion of the high-frequency signal at the switches (first switch 5 and second switch 6) and suppress the degradation of its characteristics.

[0228] Furthermore, in the high-frequency circuit 100m according to Embodiment 13, amplifier 3 is a low-noise amplifier 41 that amplifies the received signal. The first balun 7 is connected to the input terminal of amplifier 3. Therefore, the high-frequency circuit 100m according to Embodiment 13 can suppress signal distortion of the high-frequency signal (received signal) at the switches (first switch 5 and second switch 6).

[0229] The high-frequency module 500m according to Embodiment 13 includes a high-frequency circuit 100m and a mounting substrate. The structure of the mounting substrate is the same as that of the mounting substrate 501 in the high-frequency module 500 according to Embodiment 1, so the illustration and description are omitted. The high-frequency module 500m according to Embodiment 13 includes a high-frequency circuit 100m, thus it is possible to suppress the degradation of the characteristics of the high-frequency circuit 100m.

[0230] (Modified Example)

[0231] The above-described embodiments 1 to 13 are merely one of the various embodiments of the present invention. Various modifications can be made to embodiments 1 to 13 as long as the objective of the present invention is achieved, depending on the design, etc.

[0232] For example, in the high-frequency circuit 100, the first matching circuit M1 is connected between the first terminal 721 of the second coil 72 of the first balun 7 and the first switch 5, and the second matching circuit M2 is connected between the second terminal 722 of the second coil 72 of the first balun 7 and the second switch 6. However, this is not a limitation; the structure may also lack the first matching circuit M1 and the second matching circuit M2. Alternatively, in the high-frequency circuit 100, the first matching circuit M1 may be connected between the first terminal 711 of the first balun 7 and the amplifier 3, and the second matching circuit M2 may be connected between the second terminal 712 of the first balun 7 and ground. Alternatively, in the high-frequency circuit 100, the first matching circuit M1 may be connected between the first switch 5 and the first terminal 811 of the third coil 81 of the second balun 8, and the second matching circuit M2 may be connected between the second switch 6 and the second terminal 812 of the third coil 81 of the second balun 8. Alternatively, in the high-frequency circuit 100, the first matching circuit M1 can be connected between the first end 821 of the fourth coil 82 of the second balun 8 and the filter 1, and the second matching circuit M2 can be connected between the second end 822 of the fourth coil 82 of the second balun 8 and ground.

[0233] Alternatively, the communication device 600 according to Embodiment 1 may also include any of the high-frequency circuits 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, 100i, 100j, 100k, and 100m to replace the high-frequency circuit 100.

[0234] In addition, the above-mentioned elastic wave filter is an elastic wave filter that utilizes surface acoustic waves or bulk acoustic waves, but it is not limited to these. For example, it can also be an elastic wave filter that utilizes elastic interface waves, plate waves, etc.

[0235] Alternatively, the high-frequency module 500 may also have the following structure: multiple external connection terminals T0 are ball bumps, and the high-frequency module 500 does not have a second resin layer 540. The material of the ball bumps constituting each of the multiple external connection terminals T0 is, for example, gold, copper, solder, etc. Regarding the multiple external connection terminals T0, it is also possible that external connection terminals T0 composed of ball bumps and external connection terminals T0 composed of columnar electrodes coexist.

[0236] Furthermore, regarding other examples of high-frequency circuits, a 3dB hybrid coupler can be incorporated as a replacement for the first balun 7 and the second balun 8 in any of the high-frequency circuits 100, 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, 100i, 100j, 100k, and 100m. Thus, the high-frequency circuits in these other examples, like those in 100, 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, 100i, 100j, 100k, and 100m, can suppress the degradation of high-frequency circuit characteristics. If, for example, a 90° hybrid coupler is used as the 3dB hybrid coupler in the high-frequency circuits of these other examples, the additional effect of improving input and output reflection losses can also be obtained.

[0237] (Way)

[0238] The following methods are disclosed in this specification.

[0239] The high-frequency circuit (100; 100a; 100b; 100i; 100m) involved in the first method includes a filter (1), an amplifier (3), a first switch (5), a second switch (6), a first balun (7), and a second balun (8). The amplifier (3) has an input terminal and an output terminal. The amplifier (3) is connected to the filter (1). The first balun (7) has a first coil (71) and a second coil (72). The second balun (8) has a third coil (81) and a fourth coil (82). In the first balun (7), the first end (711) of the first coil (71) is connected to the input terminal and the output terminal of the amplifier (3) connected to the filter (1), and the second end (712) of the first coil (71) is connected to ground. In the first balun (7), the first end (721) of the second coil (72) is connected to the first switch (5), and the second end (722) of the second coil (72) is connected to the second switch (6). In the second balun (8), the first end (811) of the third coil (81) is connected to the first end (721) of the second coil (72) via the first switch (5), and the second end (812) of the third coil (81) is connected to the second end (722) of the second coil (72) via the second switch (6). In the second balun (8), the first end (821) of the fourth coil (82) is connected to the filter (1), and the second end (822) of the fourth coil (82) is connected to ground.

[0240] In the high-frequency circuit (100; 100a; 100b; 100i; 100m) involved in the first embodiment, switches (first switch 5 and second switch 6) acting as nonlinear devices are connected between the first balun (7) and the second balun (8), thus reducing the power applied to the switches (first switch 5 and second switch 6). Consequently, the high-frequency circuit (100; 100a; 100b; 100i; 100m) involved in the first embodiment can reduce signal distortion of the high-frequency signal at the switches (first switch 5 and second switch 6) and suppress the degradation of the characteristics of the high-frequency circuit (100; 100a; 100b; 100i; 100m).

[0241] The high-frequency circuit (100c; 100d; 100e; 100f; 100g; 100h; 100j; 100k) involved in the second method includes a first filter (1A), a second filter (1B), an amplifier (3), a first switch (5), a second switch (6), a first balun (7), and a second balun (8). The first filter (1A) has a first passband. The second filter (1B) has a second passband that is the same as the first passband. The amplifier (3) has input terminals and output terminals. The amplifier (3) is connected to the first filter (1A) and the second filter (1B). The first balun (7) has a first coil (71) and a second coil (72). The second balun (8) has a third coil (81) and a fourth coil (82). In the first balun (7), the first end (711) of the first coil (71) is connected to the input and output terminals of the amplifier (3) and connected to the first filter (1A) and the second filter (1B), and the second end (712) of the first coil (71) is connected to ground. In the first balun (7), the first end (721) of the second coil (72) is connected to the first switch (5), and the second end (722) of the second coil (72) is connected to the second switch (6). In the second balun (8), the first end (811) of the third coil (81) is connected to the first end (721) of the second coil (72) via the first filter (1A) and the first switch (5), and the second end (812) of the third coil (81) is connected to the second end (722) of the second coil (72) via the second filter (1B) and the second switch (6). In the second balanced-unbalanced converter (8), the first end (821) of the fourth coil (82) is connected to the signal path (S1), and the second end (822) of the fourth coil (82) is connected to ground.

[0242] In the high-frequency circuit (100c; 100d; 100e; 100f; 100g; 100h; 100j; 100k) involved in the second method, the switches (first switch 5 and second switch 6) which are nonlinear devices are connected between the first balun (7) and the second balun (8), thus reducing the power applied to the switches (first switch 5 and second switch 6). As a result, the high-frequency circuit (100c; 100d; 100e; 100f; 100g; 100h; 100j; 100k) involved in the second method can reduce the signal distortion of the high-frequency signal at the switches (first switch 5 and second switch 6) and can suppress the degradation of the characteristics of the high-frequency circuit (100c; 100d; 100e; 100f; 100g; 100h; 100j; 100k). Furthermore, in the high-frequency circuit (100c; 100d; 100e; 100f; 100g; 100h; 100j; 100k) involved in the second method, the filters (first filter 1A and second filter 1B) which are nonlinear devices are connected between the first balun (7) and the second balun (8), thus reducing the power applied to the filters (each of the first filter 1A and the second filter 1B). As a result, the high-frequency circuit (100c; 100d; 100e; 100f; 100g; 100h; 100j; 100k) involved in the second method can reduce the signal distortion of the high-frequency signal at the filters (each of the first filter 1A and the second filter 1B) and can suppress the degradation of the characteristics of the high-frequency circuit (100c; 100d; 100e; 100f; 100g; 100h; 100j; 100k).

[0243] The high-frequency circuit (100; 100a; 100b; 100i; 100m) involved in the third method based on the first method also includes a second filter (2) and a second amplifier (4). The second filter (2) is different from the first filter (1) which is a filter (1). The second amplifier (4) is an amplifier other than the first amplifier (3) which is an amplifier (3), and has input terminals and output terminals. The second amplifier (4) is connected to the second filter (2). The first filter (1) has a first passband. The second filter (2) has a second passband different from the first passband. The first amplifier (3) is a first power amplifier (31) that amplifies the first transmitted signal. The second amplifier (4) is a second power amplifier (32) that amplifies a second transmitted signal different from the first transmitted signal.

[0244] The high-frequency circuits (100; 100a; 100b; 100i; 100m) involved in the third approach can, for example, reduce the size of the IMD that occurs when performing dual uplink carrier aggregation using the first amplifier (3) and the second amplifier (4).

[0245] The high-frequency circuits (100c; 100d; 100e; 100f; 100g; 100h; 100j) involved in the fourth method based on the second method also include a third filter (transmit filter 12) and a second amplifier (4). The third filter (transmit filter 12) has a third passband different from the first passband. The second amplifier (4) is an amplifier other than the first amplifier (3) which is an amplifier (3), and has input terminals and output terminals. The second amplifier (4) is connected to the third filter (transmit filter 12). The first amplifier (3) is a first power amplifier (31) that amplifies the first transmitted signal. The second amplifier (4) is a second power amplifier (32) that amplifies a second transmitted signal different from the first transmitted signal.

[0246] The fourth approach (100c; 100d; 100e; 100f; 100g; 100h; 100j) can, for example, reduce the size of the IMD that occurs when performing dual uplink carrier aggregation using the first amplifier (3) and the second amplifier (4).

[0247] The high-frequency circuit (100d; 100e) based on the fifth method of the third or fourth method also includes a third balun (9). The third balun (9) has a fifth coil (91) and a sixth coil (92). In the third balun (9), the first end (911) of the fifth coil (91) is connected to the output terminal of the second amplifier (4), and the second end (912) of the fifth coil (91) is connected to ground. In the third balun (9), the first end (921) of the sixth coil (92) is connected to the first end (811) of the third coil (8) of the second balun (8) via a first switch (5), and the second end (922) of the sixth coil (92) is connected to the second end (812) of the third coil (81) of the second balun (8) via a second switch (6).

[0248] The high-frequency circuit (100d; 100e) involved in the fifth method can suppress signal distortion between the third balun (9) and the second balun (8) and can suppress the degradation of the characteristics of the high-frequency circuit (100d; 100e).

[0249] The high-frequency circuit (100j) based on the sixth method of the first or second method also includes a third switch (10), a fourth switch (switch 18), a transmitting filter (11C), and a controller (13). The third switch (10) is connected to the first end (821) of the fourth coil (82) of the second balun (8). The fourth switch (switch 18) is connected between the output terminal of the amplifier (3) and the first balun (7). The transmitting filter (11C) is connected between the fourth switch (switch 18) and the third switch (10) without passing through the first balun (7) and the second balun (8). The controller (13) controls the amplifier (3). The amplifier (3) is a power amplifier (31) that amplifies the transmitted signal. The amplifier (3) can operate in a first power mode and a second power mode, the output power of which is lower than the output power of the first power mode. When the controller (13) operates the amplifier (3) in the first power mode, the fourth switch (switch 18) makes the output terminal of the amplifier (3) connected to the first balun (7) and deconnects the output terminal of the amplifier (3) from the transmitting filter (11C). When the controller (13) operates the amplifier (3) in the second power mode, the fourth switch (switch 18) makes the output terminal of the amplifier (3) deconnect from the first balun (7) and connects the output terminal of the amplifier (3) to the transmitting filter (11C).

[0250] The high-frequency circuit (100j) involved in the sixth method can suppress signal distortion when the amplifier (3) operates in the first power mode and can suppress the degradation of the characteristics of the high-frequency circuit (100j).

[0251] The high-frequency circuit (100k) based on the seventh method (either the first or second method) also includes a third switch (10), a second amplifier (4), and a transmit filter (12C). The third switch (10) is connected to the first terminal (821) of the fourth coil (82) of the second balun (8). The second amplifier (4) is an amplifier other than the first amplifier (3) of the amplifier (3), and has input and output terminals. The transmit filter (12C) is connected between the output terminal of the second amplifier (4) and the third switch (10) without passing through the first balun (7) and the second balun (8). The first amplifier (3) supports a first power level. The second amplifier (4) supports a second power level. The maximum output power of the first power level is greater than the maximum output power of the second power level.

[0252] The high-frequency circuit (100k) involved in the seventh method can suppress signal distortion when the first amplifier (3) is operating, and can suppress the degradation of the characteristics of the high-frequency circuit (100k).

[0253] In the high-frequency circuit (100m) involved in the eighth method based on the first or second method, the amplifier (3) is a low-noise amplifier (41) that amplifies the received signal. The first balun (7) is connected to the input terminal of the amplifier (3).

[0254] The high-frequency circuit (100m) involved in the eighth method can suppress the degradation of the characteristics of the high-frequency circuit (100m).

[0255] The high-frequency module (500; 500a; 500b; 500c; 500d; 500e; 500f; 500g; 500h; 500i; 500j; 500k; 500m) involved in the ninth method comprises: a high-frequency circuit (100; 100a; 100b; 100c; 100d; 100e; 100f; 100g; 100h; 100i; 100j; 100k; 100m) of any one of the first to eighth methods; and a mounting substrate (501). The amplifier (3), first switch (5), second switch (6), first balun (7), and second balun (8) of the high-frequency circuit (100; 100a; 100b; 100c; 100d; 100e; 100f; 100g; 100h; 100i; 100j; 100k; 100m) are disposed on the mounting substrate (501).

[0256] The high-frequency modules (500; 500a; 500b; 500c; 500d; 500e; 500f; 500g; 500h; 500i; 500j; 500k; 500m) involved in the ninth method can suppress the degradation of the characteristics of the high-frequency circuits (100; 100a; 100b; 100c; 100d; 100e; 100f; 100g; 100h; 100i; 100j; 100k; 100m).

[0257] The mounting substrate (501) of the high-frequency module (500; 500a; 500b; 500c; 500d; 500e; 500f; 500g; 500h; 500i; 500j; 500k; 500m) involved in the tenth method based on the ninth method has a first main surface (511) and a second main surface (512) facing each other. An amplifier (3) is disposed on the first main surface (511) of the mounting substrate (501). A first switch (5) and a second switch (6) are disposed on the second main surface (512) of the mounting substrate (501). A first balun (7) and a second balun (8) are disposed on the mounting substrate (501). When viewed from the thickness direction (D1) of the mounting substrate (501), at least a portion of the first balancing-unbalancing converter (7) overlaps with the first switch (5) and the second switch (6), and at least a portion of the second balancing-unbalancing converter (8) overlaps with the first switch (5) and the second switch (6).

[0258] The high-frequency modules (500; 500a; 500b; 500c; 500d; 500e; 500f; 500g; 500h; 500i; 500j; 500k; 500m) involved in the tenth method can further suppress the degradation of the characteristics of the high-frequency circuits (100; 100a; 100b; 100c; 100d; 100e; 100f; 100g; 100h; 100i; 100j; 100k; 100m).

[0259] The communication device (600) involved in the eleventh method includes: a high-frequency circuit (100; 100a; 100b; 100c; 100d; 100e; 100f; 100g; 100h; 100i; 100j; 100k; 100m) of any one of the first to eighth methods; and a signal processing circuit (601). The signal processing circuit (601) is connected to the high-frequency circuit (100; 100a; 100b; 100c; 100d; 100e; 100f; 100g; 100h; 100i; 100j; 100k; 100m).

[0260] The communication device (600) involved in the eleventh method is able to suppress the degradation of the characteristics of the high-frequency circuit (100; 100a; 100b; 100c; 100d; 100e; 100f; 100g; 100h; 100i; 100j; 100k; 100m).

[0261] Explanation of reference numerals in the attached figures

[0262] 1: Filter (first filter); 1A: First filter; 1B: Second filter; 2: Second filter; 3: Amplifier (first amplifier); 301: Transistor; 302: Transistor; 303: Interstage matching circuit; 4: Amplifier (second amplifier); 5: First switch; 50: Common terminal; 51, 52, 53: Selection terminals; 6: Second switch; 60: Common terminal; 61, 62, 63: Selection terminals; 7: First balun; 71: First coil; 711: First terminal; 712: Second terminal; 72: Second coil; 721: First terminal; 722: Second terminal; 8: Second balun; 81: Third coil; 811: First terminal; 812: Second terminal; Terminals; 82: Fourth coil; 821: First terminal; 822: Second terminal; 9: Third balun; 91: Fifth coil; 911: First terminal; 912: Second terminal; 92: Sixth coil; 921: First terminal; 922: Second terminal; 10: Third switch; 101, 102: First terminals; 111, 112: Second terminals; 11: Transmit filter (first transmit filter); 11A: First transmit filter; 11B: Second transmit filter; 11C: Transmit filter; 12: Transmit filter (second transmit filter, third filter); 12C: Transmit filter; 13: Controller; 14: Fourth switch; 140: Common terminal; 141, 142, 143: Selection terminals; 15: Fifth switch; 150: Common terminal; 151, 152, 153: Select terminals; 16: Sixth switch; 161, 162: First terminals; 165, 166: Second terminals; 17: Fourth balun; 171: Seventh coil; 1711: First terminal; 1712: Second terminal; 172: Eighth coil; 1721: First terminal; 1722: Second terminal; 18: Switch (fourth switch); 180: Common terminal; 181, 182: Select terminals; 21: Receiver filter (first receiver filter); 22: Receiver filter (second receiver filter); 31: Power amplifier (first power amplifier); 32: Power amplifier (second power amplifier); 41: Low noise Amplifier (first low-noise amplifier); 42: Low-noise amplifier (second low-noise amplifier); 100, 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, 100i, 100j, 100k, 100m: High-frequency circuit; 500, 500a, 500b, 500c, 500d, 500e, 500f, 500g, 500h, 500i, 500j, 500k, 500m: High-frequency module; 501: Mounting substrate; 511: First main surface; 512: Second main surface; 520: Resin layer (first resin layer); 521: Main surface; 523: Outer peripheral surface; 530: Metal electrode layer; 540: Second resin layer;541: Main surface; 543: Outer peripheral surface; 600: Communication device; 601: Signal processing circuit; 602: RF signal processing circuit; 603: Baseband signal processing circuit; A1: Antenna (first antenna); A2: Second antenna; Ba1: Balancing-to-unbalanced converter; D1: Thickness direction; E1: Electronic component; E2: Electronic component; S1: Signal path; M1: First matching circuit; M11: Circuit element; M2: Second matching circuit; M12: Circuit element; T0: External connection terminal; T1: Antenna terminal (first antenna terminal); T2: Second antenna terminal; T3: First signal input terminal; T4: Second signal input terminal; T5: First signal output terminal; T6: Second signal output terminal; T7: Control terminal; T8: Ground terminal.

Claims

1. A high-frequency circuit, comprising: filter; An amplifier having input and output terminals is connected to the filter; First switch; Second switch; A first balun has a first coil and a second coil; and The second balun has a third and a fourth coil. wherein In the first balanced-to-unbalanced converter The first end of the first coil is connected to the input terminal and the output terminal of the amplifier, which are connected to the filter. The second end of the first coil is connected to ground. The first end of the second coil is connected to the first switch. The second end of the second coil is connected to the second switch. In the second balanced-to-unbalanced converter The first end of the third coil is connected to the first end of the second coil via the first switch. The second end of the third coil is connected to the second end of the second coil via the second switch. The first end of the fourth coil is connected to the filter. The second end of the fourth coil is connected to ground.

2. A high-frequency circuit, comprising: A first filter having a first passband; A second filter having the same second passband as the first passband; An amplifier having input and output terminals, connected to the first filter and the second filter; First switch; Second switch; A first balun has a first coil and a second coil; and The second balun has a third and a fourth coil. In the first balanced-to-unbalanced converter, The first end of the first coil is connected to the input terminal and the output terminal of the amplifier, which are connected to the first filter and the second filter. The second end of the first coil is connected to ground. The first end of the second coil is connected to the first switch. The second end of the second coil is connected to the second switch. In the second balanced-to-unbalanced converter The first end of the third coil is connected to the first end of the second coil via the first filter and the first switch. The second end of the third coil is connected to the second end of the second coil via the second filter and the second switch. The first end of the fourth coil is connected to the signal path. The second end of the fourth coil is connected to ground.

3. The high-frequency circuit according to claim 1, wherein It also has: A second filter, which is different from the first filter that is said filter; and The second amplifier, which is an additional amplifier besides the first amplifier, has input and output terminals and is connected to the second filter. The first filter has a first passband. The second filter has a second passband that is different from the first passband. The first amplifier is a first power amplifier that amplifies the first transmitted signal. The second amplifier is a second power amplifier that amplifies a second transmitted signal that is different from the first transmitted signal.

4. The high frequency circuit according to claim 2, wherein It also has: A third filter having a third passband different from the first passband; and The second amplifier, which is an additional amplifier besides the first amplifier, has input and output terminals and is connected to the third filter. The first amplifier is a first power amplifier that amplifies the first transmitted signal. The second amplifier is a second power amplifier that amplifies a second transmitted signal that is different from the first transmitted signal.

5. The high-frequency circuit according to claim 3 or 4, wherein, It also features a third balun, which has a fifth and a sixth coil. In the third balanced-to-unbalanced converter, The first end of the fifth coil is connected to the output terminal of the second amplifier. The second end of the fifth coil is connected to ground. The first end of the sixth coil is connected to the first end of the third coil of the second balun via the first switch. The second end of the sixth coil is connected to the second end of the third coil of the second balun via the second switch.

6. The high-frequency circuit according to claim 1 or 2, wherein It also has: A third switch is connected to the first end of the fourth coil of the second balun; A fourth switch is connected between the output terminal of the amplifier and the first balun; A transmitting filter is connected between the fourth switch and the third switch without passing through the first and second baluns; and A controller that controls the amplifier. The amplifier mentioned above is a power amplifier that amplifies the transmitted signal. The amplifier is capable of operating in a first power mode and a second power mode, wherein the output power of the second power mode is lower than that of the first power mode. When the controller causes the amplifier to operate in the first power mode, the fourth switch makes the output terminal of the amplifier connected to the first balun and deconnected from the output terminal of the amplifier to the transmitting filter. When the controller causes the amplifier to operate in the second power mode, the fourth switch de-connects the output terminal of the amplifier to the first balun and turns the output terminal of the amplifier to the transmit filter.

7. The high-frequency circuit according to claim 1 or 2, wherein It also has: A third switch is connected to the first end of the fourth coil of the second balun; The second amplifier, which is an additional amplifier besides the first amplifier, has input terminals and output terminals; as well as A transmit filter is connected between the output terminal of the second amplifier and the third switch in a manner that bypasses both the first and second baluns. The first amplifier supports a first power level. The second amplifier supports a second power level. The maximum output power of the first power level is greater than the maximum output power of the second power level.

8. The high-frequency circuit according to claim 1 or 2, wherein, The amplifier is a low-noise amplifier that amplifies the received signal. The first balun is connected to the input terminal of the amplifier.

9. A high-frequency module, comprising: The high-frequency circuit according to any one of claims 1 to 8; and Mounting substrate wherein, The amplifier, the first switch, the second switch, the first balun, and the second balun of the high-frequency circuit are disposed on the mounting substrate.

10. The high-frequency module according to claim 9, wherein, The mounting substrate has a first main surface and a second main surface facing each other. The amplifier is disposed on the first main surface of the mounting substrate. The first switch and the second switch are disposed on the second main surface of the mounting substrate. The first balun and the second balun are disposed on the mounting substrate. When viewed from the thickness direction of the mounting substrate, At least a portion of the first balanced-to-unbalanced converter overlaps with the first switch and the second switch. At least a portion of the second balanced-to-unbalanced converter overlaps with the first switch and the second switch.

11. A communication device comprising: The high-frequency circuit according to any one of claims 1 to 8; and A signal processing circuit, which is connected to the high-frequency circuit.

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