High frequency circuits

Abstract

The high-frequency circuit (1) includes: a switching circuit (51) including a common terminal (511) connected to an antenna connection terminal (101) and selection terminals (512 and 513); a switching circuit (52) including a common terminal (521) connected to the selection terminal (512) and selection terminals (522 and 523); a transmit filter (31) connected to the selection terminal (513) and having a passband that includes a transmit band (A) supporting a first power level (e.g., power level 2); a receive filter (41) connected to the selection terminal (522) and having a passband that includes a receive band (A); and at least one of a transmit filter (32) and a receive filter (42) connected to the selection terminal (523), wherein the transmit filter (32) has a passband that includes a transmit band (B) supporting a second power level (e.g., power level 3), and the receive filter (42) has a passband that includes a receive band (B).

Description

Technical Field

[0001] This invention relates to a high-frequency circuit. Background Technology

[0002] A high-frequency circuit that supports a power level (e.g., power level 2) that allows for a higher maximum output power than previously possible has been proposed. For example, Patent Document 1 discloses a high-frequency circuit that includes a duplexer circuit connected to a power amplifier circuit supporting a first power level and a duplexer circuit connected to a power amplifier circuit supporting a second power level.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2022 / 138373 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] However, in the aforementioned prior art, when multiple filters are required to support multiple frequency bands, the loss of transmitted signals caused by the switching circuits used to connect the multiple filters can sometimes become a problem.

[0008] Therefore, the present invention provides a high-frequency circuit that can reduce the loss of transmitted signals.

[0009] Solution for solving the problem

[0010] One aspect of the present invention relates to a high-frequency circuit comprising: a first switching circuit including a first common terminal connected to an antenna connection terminal, and a first selection terminal and a second selection terminal; a second switching circuit including a second common terminal connected to the first selection terminal, and a third selection terminal and a fourth selection terminal; a first transmit filter connected to the second selection terminal, having a passband including a transmit band supporting a first FDD frequency band at a first power level defined by a first maximum output power; a first receive filter connected to the third selection terminal, having a passband including a receive band of the first FDD frequency band; and at least one of a second transmit filter and a second receive filter connected to the fourth selection terminal, the second transmit filter having a passband including a transmit band supporting a second frequency band at a second maximum output power lower than the first maximum output power, and the second receive filter having a passband including a receive band of a third frequency band.

[0011] The effects of the invention

[0012] According to the present invention, signal loss can be reduced. Attached Figure Description

[0013] Figure 1 This is a circuit structure diagram of the high-frequency circuit involved in the implementation method.

[0014] Figure 2 This is a circuit structure diagram illustrating the first communication mode of the high-frequency circuit involved in the embodiment.

[0015] Figure 3 This is a circuit structure diagram illustrating the second communication mode of the high-frequency circuit involved in the embodiment.

[0016] Figure 4 This is a circuit structure diagram illustrating the third communication mode of the high-frequency circuit involved in the embodiment.

[0017] Figure 5 This is a circuit structure diagram illustrating the fourth communication mode of the high-frequency circuit involved in the embodiment.

[0018] Figure 6 This is a circuit structure diagram illustrating the fifth communication mode of the high-frequency circuit involved in the embodiment.

[0019] Figure 7 This is a top view of the high-frequency circuit involved in the implementation method. Detailed Implementation

[0020] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Furthermore, the embodiments described below are general or specific examples. The numerical values, shapes, materials, structural elements, arrangements of structural elements, and connection methods shown in the following embodiments are examples and are not intended to limit the present invention.

[0021] In the figures below, the x-axis and y-axis are mutually orthogonal axes on a plane parallel to the main surface of the module substrate. Specifically, when the module substrate has a rectangular shape when viewed from above, the x-axis is parallel to the first side of the module substrate, and the y-axis is parallel to the second side of the module substrate orthogonal to the first side. Additionally, the z-axis is perpendicular to the main surface of the module substrate; the positive direction of the z-axis represents the upward direction, and the negative direction represents the downward direction.

[0022] Furthermore, the figures are schematic diagrams that have been appropriately emphasized, omitted, or proportionally adjusted for the purpose of illustrating the invention, and are not necessarily strictly illustrative, sometimes differing from the actual shapes, positional relationships, and proportions. In the figures, substantially identical structures are labeled with the same reference numerals, and sometimes repeated descriptions are omitted or simplified.

[0023] In this disclosure, "connection" includes not only direct connections via connecting terminals and / or wiring conductors, but also electrical connections via other circuit elements. "A connected between B and C" means that A is connected in series along the path connecting B and C; specifically, it means that one end of A is connected to B and the other end of A is connected to C. "Terminal" refers to the point where a conductor within an element terminates. Furthermore, where the impedance of the conductors between elements is sufficiently low, a terminal can be interpreted as any point on the conductors between elements or the entire conductor, rather than just a single point.

[0024] The "passband of a filter" is a portion of the spectrum transmitted through the filter, defined as the frequency band where the output power is no more than 3dB lower than the maximum output power. Therefore, the high-frequency and low-frequency ends of the passband of a bandpass filter are determined as the higher and lower frequencies of the two points where the output power is 3dB lower than the maximum output power.

[0025] "Receive band" refers to the frequency band used for receiving in a communication device, while "transmit band" refers to the frequency band used for transmitting in a communication device. For example, in the frequency band used for Frequency Division Duplex (FDD), different frequency bands (uplink band and downlink band) are used as the transmit and receive bands. Conversely, in the frequency band used for Time Division Duplex (TDD), the transmit and receive bands use the same frequency band.

[0026] "Component disposed on the main surface of the substrate" includes not only components disposed in contact with the main surface of the substrate, but also components disposed on top of the main surface in a manner that does not contact the main surface (e.g., components stacked on top of other components disposed in contact with the main surface). Additionally, "component disposed on the main surface of the substrate" may also include components disposed in a recess formed on the main surface.

[0027] "A is positioned between B and C" means that at least one of the multiple line segments connecting any point in B to any point in C passes through A. "A is positioned closer to C than B" means that the distance between A and C is shorter than the distance between B and C. Here, "the distance between A(B) and C" represents the length of the shortest line segment connecting any point in A(B) to any point in C.

[0028] "Top view of module substrate" means that the object is projected onto the xy plane from the positive side of the z-axis for observation.

[0029] In addition, terms such as "parallel" and "perpendicular" indicate the relationship between elements, terms such as "rectangle" indicate the shape of elements, and numerical ranges indicate substantially equivalent ranges, such as including a few percent of error, rather than just indicating a strict meaning.

[0030] (Implementation Method)

[0031] Description of the implementation method. The communication device 5 involved in this implementation method can be used to provide wireless connectivity. For example, the communication device 5 can be installed in user equipment (UE) in cellular networks (also known as mobile networks) such as portable phones, smartphones, tablet computers, and wearable devices. In another example, by installing the communication device 5, wireless connectivity can be provided to IoT (Internet of Things) sensor devices, medical / healthcare devices, automobiles, unmanned aerial vehicles (UAVs), and automated guided vehicles (AGVs). In yet another example, by installing the communication device 5, wireless connectivity can also be provided using wireless access points or wireless hotspots.

[0032] Reference Figure 1 The circuit structure of the communication device 5 and the high-frequency circuit 1 involved in this embodiment will be explained. Figure 1 This is a circuit diagram of the communication device 5 involved in this embodiment.

[0033] also, Figure 1 This is an illustrative circuit structure; the communication device 5 and the high-frequency circuit 1 can be installed using any of a variety of circuit mounting methods and circuit techniques. Therefore, the following description of the communication device 5 and the high-frequency circuit 1 should not be interpreted restrictively.

[0034] [1. Circuit structure of communication device 5]

[0035] First, refer to Figure 1 The circuit structure of the communication device 5 according to this embodiment will be explained. The communication device 5 includes a high-frequency circuit 1, an antenna 2, an RFIC (Radio Frequency Integrated Circuit) 3, and a BBIC (Baseband Integrated Circuit) 4.

[0036] High-frequency circuit 1 is capable of transmitting high-frequency signals between antenna 2 and RFIC 3. The circuit structure of high-frequency circuit 1 will be described later.

[0037] Antenna 2 is connected to antenna connection terminal 101 of high-frequency circuit 1. Antenna 2 can receive high-frequency signals from high-frequency circuit 1 and output them to the outside of communication device 5. Alternatively, antenna 2 can also receive high-frequency signals from outside of communication device 5 and output them to high-frequency circuit 1. Furthermore, antenna 2 may not be included in communication device 5. Alternatively, communication device 5 may have one or more antennas in addition to antenna 2.

[0038] RFIC 3 is an example of a signal processing circuit that processes high-frequency signals. Specifically, RFIC 3 can process the transmit signal input from BBIC 4 through up-conversion or the like, and output the resulting high-frequency transmit signal to high-frequency circuit 1. Furthermore, RFIC 3 can process the high-frequency receive signal input via the receive path of high-frequency circuit 1 through down-conversion or the like, and output the resulting receive signal to BBIC 4. Additionally, RFIC 3 may also have a control unit that controls the switches and power amplifiers in high-frequency circuit 1. Moreover, some or all of the functions of the control unit in RFIC 3 may be included externally, for example, within BBIC 4 or high-frequency circuit 1.

[0039] BBIC 4 is a baseband signal processing circuit that uses an intermediate frequency band (IF) with a frequency lower than that of the high-frequency signal transmitted by the high-frequency circuit 1 for signal processing. Signals processed by BBIC 4 may be used, for example, as image signals to display images and / or as sound signals to make calls via a speaker. Alternatively, BBIC 4 may not be included in the communication device 5.

[0040] [2. Circuit structure of high-frequency circuit 1]

[0041] Next, refer to Figure 1 The circuit structure of the high-frequency circuit 1 according to this embodiment will be described below. The high-frequency circuit 1 includes power amplifiers 11 and 12, low-noise amplifiers 21 to 23, transmitting filters 31 to 33, receiving filters 41 to 43, switching circuits 51 to 53, variable phase circuit 61, antenna connection terminal 101, high-frequency input terminals 111 and 112, and high-frequency output terminals 121 to 123.

[0042] Antenna connection terminal 101 is an external connection terminal of high-frequency circuit 1. Antenna connection terminal 101 is connected to antenna 2 externally to high-frequency circuit 1 and to switching circuit 51 internally to high-frequency circuit 1. Thus, high-frequency circuit 1 can supply transmission signals to antenna 2 via antenna connection terminal 101 and can receive signals from antenna 2.

[0043] High-frequency input terminals 111 and 112 are external connection terminals of the high-frequency circuit 1. High-frequency input terminals 111 and 112 are externally connected to the RFIC 3 and internally connected to power amplifiers 11 and 12, respectively. Thus, the high-frequency circuit 1 can supply the transmission signals of frequency bands A and C received from the RFIC 3 via high-frequency input terminal 111 to power amplifier 11, and can supply the transmission signal of frequency band B received from the RFIC 3 via high-frequency input terminal 112 to power amplifier 12.

[0044] High-frequency output terminals 121-123 are external connection terminals of high-frequency circuit 1. High-frequency output terminals 121-123 are externally connected to RFIC 3 and internally connected to low-noise amplifiers 21-23, respectively. Thus, high-frequency circuit 1 can supply received signals in frequency bands A-C to RFIC 3 via high-frequency output terminals 121-123.

[0045] Power amplifier 11 is connected between high-frequency input terminal 111 and switching circuit 53. Specifically, the input terminal of power amplifier 11 is connected to high-frequency input terminal 111, and the output terminal of power amplifier 11 is connected to switching circuit 53. Power amplifier 11 can amplify the transmitted signals in frequency bands A and C supplied from RFIC 3 via high-frequency input terminal 111 using power supplied from a power source (not shown). Power amplifier 11 supports a first power level.

[0046] Power amplifier 12 is connected between high-frequency input terminal 112 and transmit filter 32. Specifically, the input of power amplifier 12 is connected to high-frequency input terminal 112, and the output of power amplifier 12 is connected to transmit filter 32. Power amplifier 12 can amplify the transmit signal of frequency band B supplied from RFIC 3 via high-frequency input terminal 112 using power supplied from a power source (not shown). Power amplifier 12 can also support a second power level, but does not support the first power level.

[0047] Power amplifiers 11 and 12 can be constructed from heterojunction bipolar transistors (HBTs) and can be manufactured using semiconductor materials. Examples of semiconductor materials include silicon germanium (SiGe) or gallium arsenide (GaAs). Furthermore, the amplifying transistors of power amplifiers 11 and 12 are not limited to HBTs. For example, power amplifier 11 can also be constructed from a high-electron-mobility transistor (HEMT) or a metal-semiconductor field-effect transistor (MESFET). In this case, gallium nitride (GaN) or silicon carbide (SiC) can also be used as the semiconductor material.

[0048] Furthermore, power amplifier 11 may be partially or entirely excluded from high-frequency circuit 1. In this case, power amplifier 11 may be partially or entirely connected between RFIC 3 and high-frequency input terminal 111, or it may be included in RFIC 3. Similarly, power amplifier 12 may be partially or entirely excluded from high-frequency circuit 1. In this case, power amplifier 12 may be partially or entirely connected between RFIC 3 and high-frequency input terminal 112, or it may be included in RFIC 3.

[0049] The first power level is a power level defined by a first maximum output power. The first power level can also be power level 2, defined by, for example, a maximum output power of 26 dBm. The second power level is a power level defined by a second maximum output power lower than the first maximum output power. The second power level can also be power level 3, defined by, for example, a maximum output power of 23 dBm. Furthermore, the first and second power levels are not limited to power level 2 and power level 3. For example, the first power level can also be power level 1.5, and the second power level can also be power level 5.

[0050] Power class is a classification of the output power of a terminal based on its maximum output power. The smaller the power class value, the higher the maximum allowable output power. For example, in 3GPP, the maximum output power for power class 1 is specified as 31 dBm, for power class 1.5 it is specified as 29 dBm, for power class 2 it is specified as 26 dBm, for power class 3 it is specified as 23 dBm, and for power class 5 it is specified as 20 dBm.

[0051] The maximum output power of the terminal is defined by the maximum output power at the antenna end. The maximum output power of the UE is determined using methods defined by 3GPP, etc. For example, in... Figure 1 In this method, the maximum output power is determined by measuring the radiated power at antenna 2. Alternatively, instead of measuring the radiated power, a terminal can be placed near antenna 2, and a measuring instrument (such as a spectrum analyzer) can be connected to that terminal to measure the maximum output power of antenna 2.

[0052] A low-noise amplifier 21 is connected between the receiving filter 41 and the high-frequency output terminal 121. Specifically, the input terminal of the low-noise amplifier 21 is connected to the receiving filter 41, and the output terminal of the low-noise amplifier 21 is connected to the high-frequency output terminal 121. The low-noise amplifier 21 can amplify the received signal in frequency band A that has passed through the receiving filter 41 using power supplied from a power source (not shown).

[0053] A low-noise amplifier 22 is connected between the receiving filter 42 and the high-frequency output terminal 122. Specifically, the input terminal of the low-noise amplifier 22 is connected to the receiving filter 42, and the output terminal of the low-noise amplifier 22 is connected to the high-frequency output terminal 122. The low-noise amplifier 22 can amplify the received signal in frequency band B that has passed through the receiving filter 42 using power supplied from a power source (not shown).

[0054] A low-noise amplifier 23 is connected between the receiving filter 43 and the high-frequency output terminal 123. Specifically, the input terminal of the low-noise amplifier 23 is connected to the receiving filter 43, and the output terminal of the low-noise amplifier 23 is connected to the high-frequency output terminal 123. The low-noise amplifier 23 can amplify the received signal in frequency band C that has passed through the receiving filter 43 using power supplied from a power source (not shown).

[0055] The low-noise amplifiers 21-23 can be constructed using field-effect transistors (FETs) and can be manufactured using semiconductor materials. Examples of semiconductor materials include single-crystal silicon, gallium nitride (GaN), or silicon carbide (SiC). Furthermore, the amplifying transistors in the low-noise amplifiers 21-23 are not limited to FETs. For example, some or all of the low-noise amplifiers 21-23 can also be constructed using bipolar transistors.

[0056] Furthermore, some or all of the low-noise amplifiers 21-23 may not be included in the high-frequency circuit 1. In this case, some or all of the low-noise amplifier 21 may be connected between the high-frequency output terminal 121 and the RFIC 3, some or all of the low-noise amplifier 22 may be connected between the high-frequency output terminal 122 and the RFIC 3, and some or all of the low-noise amplifier 23 may be connected between the high-frequency output terminal 123 and the RFIC 3. Alternatively, some or all of the low-noise amplifiers 21-23 may also be included in the RFIC 3.

[0057] Transmit filter 31 is an example of a first transmit filter and has a passband that includes the transmit frequency band A. Transmit filter 31 has power tolerance supporting a first power level. Transmit filter 31 is connected between switching circuits 51 and 53. Specifically, one end of transmit filter 31 is connected to the select terminal 513 of switching circuit 51, and the other end of transmit filter 31 is connected to the select terminal 532 of switching circuit 53.

[0058] Transmit filter 32 is an example of a second transmit filter, having a passband that includes the transmit frequency band B. Transmit filter 32 may also have power tolerance supporting a second power level, but not power tolerance supporting a first power level. Transmit filter 32 is connected between switching circuit 52 and power amplifier 12. Specifically, one end of transmit filter 32 is connected to the selection terminal 523 of switching circuit 52, and the other end of transmit filter 32 is connected to the output terminal of power amplifier 12. Furthermore, transmit filter 32 may not be included in high-frequency circuit 1.

[0059] Transmit filter 33 is an example of a third transmit filter, having a passband that includes the transmit frequency band C. Transmit filter 33 has power tolerance supporting a first power level. Transmit filter 33 is connected between switching circuits 51 and 53. Specifically, one end of transmit filter 33 is connected to the selection terminal 514 of switching circuit 51, and the other end of transmit filter 33 is connected to the selection terminal 533 of switching circuit 53. Alternatively, transmit filter 33 may not be included in the high-frequency circuit 1. In this case, switching circuit 51 may not include selection terminal 514.

[0060] As transmitting filters 31-33, surface acoustic wave (SAW) filters, bulk acoustic wave (BAW) filters, LC resonant filters, dielectric resonant filters, or any combination thereof may be used, and they are not limited to these. For example, transmitting filters 31 and 33 may also be BAW filters with higher power tolerance, and transmitting filter 32 may also be an SAW filter with lower power tolerance.

[0061] The receiving filter 41 is an example of a first receiving filter and has a passband that includes the receiving frequency band A. The receiving filter 41 is connected between the switching circuit 52 and the low-noise amplifier 21. Specifically, one end of the receiving filter 41 is connected to the selection terminal 522 of the switching circuit 52, and the other end of the receiving filter 41 is connected to the input terminal of the low-noise amplifier 21.

[0062] The receiving filter 42 is an example of a second receiving filter, having a passband that includes the receiving band of frequency band B. The receiving filter 42 is connected between the switching circuit 52 and the low-noise amplifier 22. Specifically, one end of the receiving filter 42 is connected to the selection terminal 523 of the switching circuit 52, and the other end of the receiving filter 42 is connected to the input terminal of the low-noise amplifier 22. Furthermore, the receiving filter 42 may not be included in the high-frequency circuit 1. Additionally, the passband of the receiving filter 42 may not include the receiving band of frequency band B, or it may include the receiving bands of other frequency bands. In this case, the receiving filter 42 may also be connected to an additional selection terminal of the switching circuit 52.

[0063] The receiving filter 43 is an example of a third receiving filter, having a passband that includes the receiving frequency band C. The receiving filter 43 is connected between the switching circuit 52 and the low-noise amplifier 23. Specifically, one end of the receiving filter 43 is connected to the selection terminal 522 of the switching circuit 52, and the other end of the receiving filter 43 is connected to the input terminal of the low-noise amplifier 23. Alternatively, the receiving filter 43 may not be included in the high-frequency circuit 1. Furthermore, the receiving filter 43 may not be connected to the selection terminal 522, or it may be connected to an additional selection terminal of the switching circuit 52.

[0064] As receiving filters 41-43, SAW filters, BAW filters, LC resonant filters or dielectric resonant filters, or any combination thereof, may also be used, and are not limited to them.

[0065] Frequency bands A through C are frequency bands used in communication systems built using Radio Access Technology (RAT). Frequency bands A through C are predefined by standardization organizations such as 3GPP (3rd Generation Partnership Project) and IEEE (Institute of Electrical and Electronics Engineers). Examples of communication systems include 5G NR (5th Generation New Radio) systems, LTE (Long Term Evolution) systems, and WLAN (Wireless Local Area Network) systems.

[0066] Frequency band A is an example of a first FDD frequency band, supporting a first power level. Frequency band A is an FDD frequency band, for example, it is Band 1 for LTE or n1 for 5G NR. Alternatively, for example, frequency band A can also be Band 3 for LTE or n3 for 5G NR, or it can be Band 40 for LTE or n40 for 5G NR.

[0067] Frequency band B is an example of the second and third frequency bands and does not support the first power level. Frequency band B can be either an FDD or TDD band. When frequency band B is a TDD band, transmit filter 32 and receive filter 42 can be combined into a single transmit / receive filter. Frequency band B can be, for example, Band 25 for LTE or n25 for 5G NR. Alternatively, frequency band B can also be, for example, Band 66 for LTE or n66 for 5G NR.

[0068] Band C is an example of the fourth FDD band, supporting the first power level. Band C is an FDD band different from Band A, such as Band 3 for LTE or n3 for 5G NR. Alternatively, for example, Band C could also be Band 1 for LTE or n1 for 5G NR, or Band 40 for LTE or n40 for 5G NR.

[0069] Switching circuit 51 is an example of a first switching circuit and is sometimes referred to as an antenna switch. Switching circuit 51 is connected between antenna connection terminal 101 and transmit filters 31 and 32, and switching circuit 52. Specifically, switching circuit 51 includes a common terminal 511 and select terminals 512-514. Common terminal 511 is an example of a first common terminal and is connected to antenna connection terminal 101. Select terminal 512 is an example of a first select terminal and is connected to common terminal 521 of switching circuit 52 via variable phase circuit 61. Select terminal 513 is an example of a second select terminal and is connected to transmit filter 31. Select terminal 514 is an example of a fifth select terminal and is connected to transmit filter 33.

[0070] In this connection structure, the switching circuit 51 can connect the common terminal 511 to at least one of the selection terminals 512-514 based on a control signal, for example, from RFIC 3. That is, the switching circuit 51 can connect the common terminal 511 to any one of the selection terminals 512-514, and can also connect it to at least two of the selection terminals 512-514 simultaneously. The switching circuit 51 is, for example, a multi-connection type switching circuit.

[0071] Switching circuit 52 is an example of a second switching circuit and is sometimes referred to as an antenna switch. Switching circuit 52 is connected between switching circuit 51 and transmitting filter 32 and receiving filters 41-43. Specifically, switching circuit 52 includes a common terminal 521 and selection terminals 522 and 523. Common terminal 521 is an example of a second common terminal and is connected to selection terminal 512 of switching circuit 51 via variable phase circuit 61. Selection terminal 522 is an example of a third selection terminal and is connected to receiving filters 41 and 43. Selection terminal 523 is an example of a fourth selection terminal and is connected to transmitting filter 32 and receiving filter 42.

[0072] In this connection structure, the switching circuit 52 can connect the common terminal 521 to at least one of the selection terminals 522 and 523 based on, for example, a control signal from the RFIC 3. That is, the switching circuit 52 can connect the common terminal 521 to either the selection terminals 522 and 523, or it can connect to both selection terminals 522 and 523 simultaneously. The switching circuit 52 is, for example, a multi-connection type switching circuit.

[0073] Switching circuit 53 is an example of a third switching circuit and is sometimes referred to as a band selection switch. Switching circuit 53 is connected between power amplifier 11 and transmit filters 31 and 33. Specifically, switching circuit 53 includes a common terminal 531 and selection terminals 532 and 533. Common terminal 531 is an example of a third common terminal and is connected to the output of power amplifier 11. Selection terminal 532 is an example of a sixth selection terminal and is connected to transmit filter 31. Selection terminal 533 is an example of a seventh selection terminal and is connected to transmit filter 33.

[0074] In this connection structure, the switching circuit 53 can exclusively connect the common terminal 531 to the select terminals 532 and 533 based on, for example, a control signal from RFIC 3. The switching circuit 53 is, for example, constructed as an SPDT (Single-Pole Double-Throw) type switching circuit.

[0075] Switching circuits 51 and 53 are mounted using CMOS-SOI (Complementary Metal-Oxide-Semiconductor Silicon-on-Insulator), while switching circuit 52 is mounted using bulk CMOS. However, the mounting methods for switching circuits 51 to 53 are not limited to these. For example, switching circuits 51 and / or 53 can also be mounted using bulk CMOS, and switching circuit 52 can also be mounted using CMOS-SOI.

[0076] A variable phase circuit 61 is connected between switching circuits 51 and 52. Specifically, the variable phase circuit 61 is connected between the selection terminal 512 of switching circuit 51 and the common terminal 521 of switching circuit 52. The variable phase circuit 61 can adjust the phase shift according to the filter connected to the common terminal 511.

[0077] For example, when the transmit filter 31 and receive filter 41 are simultaneously connected to the common terminal 511 for transmitting and receiving signals in band A, the phase shift of the variable phase circuit 61 is adjusted to a phase shift that makes the impedance of the transmit band of band A close to an open circuit when viewed from the common terminal 511. This suppresses intermodulation distortion and other distortions caused by leakage of the transmit signal from band A into the receive path.

[0078] Furthermore, for example, when the transmit filter 33 and receive filter 43 are simultaneously connected to the common terminal 511 for transmitting and receiving signals in band C, the phase shift of the variable phase circuit 61 is adjusted to a phase shift that makes the impedance of the transmit band of band C close to an open circuit when viewed from the common terminal 511. This suppresses intermodulation distortion and other distortions caused by leakage of the transmitted signal from band C into the receiving path.

[0079] Furthermore, the circuit structure of the variable phase circuit 61 is not particularly limited. For example, the variable phase circuit 61 may also be composed of a switch, an inductor, and / or a capacitor. Additionally, the variable phase circuit 61 may not be included in the high-frequency circuit 1.

[0080] [3. Communication Mode of High-Frequency Circuit 1]

[0081] Next, the frequency band used in the communication and the communication mode of the high-frequency circuit 1 that supports the power level applied to the frequency band will be explained.

[0082] [3.1. First Communication Mode]

[0083] First, refer to Figure 2 This will illustrate the first communication mode of high-frequency circuit 1. Figure 2 This is a circuit structure diagram showing the first communication mode of the high-frequency circuit 1 according to this embodiment. In this figure and the following figures, dashed arrows indicate the flow of high-frequency signals.

[0084] The first communication mode is a communication mode for transmitting signals in frequency band A at a first power level (e.g., power level 2). In the first communication mode, the transmission of signals in the transmit band of frequency band A is not simultaneous with the reception of signals in the receive band of frequency band A.

[0085] In the first communication mode, the switching circuit 51 connects the common terminal 511 to the selection terminal 513, but not to the selection terminals 512 and 514. Furthermore, the switching circuit 53 connects the common terminal 531 to the selection terminal 532, but not to the selection terminal 533. Thus, one end of the transmitting filter 31 is connected to the antenna connection terminal 101 via the switching circuit 51, and the other end of the transmitting filter 31 is connected to the power amplifier 11 via the switching circuit 53.

[0086] As a result, the transmit signal of band A is transmitted from RFIC 3 to antenna 2 via high-frequency input terminal 111, power amplifier 11, switching circuit 53, transmit filter 31, switching circuit 51 and antenna connection terminal 101.

[0087] [3.2. Second Communication Mode]

[0088] Next, refer to Figure 3 This will illustrate the second communication mode of high-frequency circuit 1. Figure 3 This is a circuit structure diagram showing the second communication mode of the high-frequency circuit 1 involved in this embodiment.

[0089] The second communication mode is a communication mode for transmitting and receiving signals in frequency band A at a second power level (e.g., power level 3). In the second communication mode, the transmission of signals in the transmission band of frequency band A is performed simultaneously with the reception of signals in the reception band of frequency band A.

[0090] In the second communication mode, switch circuit 51 connects common terminal 511 to select terminals 512 and 513, but not to select terminal 514. Switch circuit 52 connects common terminal 521 to select terminal 522, but not to select terminal 523. Switch circuit 53 connects common terminal 531 to select terminal 532, but not to select terminal 533. Thus, one end of the transmitting filter 31 is connected to antenna connection terminal 101 via switch circuit 51, and the other end of the transmitting filter 31 is connected to power amplifier 11 via switch circuit 53. Furthermore, one end of the receiving filter 41 is connected to antenna connection terminal 101 via switch circuit 52, variable phase circuit 61, and switch circuit 51.

[0091] As a result, the transmit signal of band A is transmitted from RFIC 3 to antenna 2 via high-frequency input terminal 111, power amplifier 11, switching circuit 53, transmit filter 31, switching circuit 51, and antenna connection terminal 101. Conversely, the receive signal of band A is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 101, switching circuit 51, variable phase circuit 61, switching circuit 52, receive filter 41, low-noise amplifier 21, and high-frequency output terminal 121.

[0092] [3.3. Third Communication Mode]

[0093] Next, refer to Figure 4 This will illustrate the third communication mode of high-frequency circuit 1. Figure 4 This is a circuit structure diagram showing the third communication mode of the high-frequency circuit 1 involved in this embodiment.

[0094] The third communication mode is a communication mode used for transmitting and receiving signals in band B at a second power level (e.g., power level 3). In the third communication mode, the transmission of signals in the transmit band of band B is performed simultaneously with the reception of signals in the receive band of band B.

[0095] In the third communication mode, the switching circuit 51 connects the common terminal 511 to the selection terminal 512, but not to the selection terminals 513 and 514. Furthermore, the switching circuit 52 connects the common terminal 521 to the selection terminal 523, but not to the selection terminal 522. Thus, one end of the transmitting filter 32 and the receiving filter 42 is connected to the antenna connection terminal 101 via the switching circuit 52, the variable phase circuit 61, and the switching circuit 52.

[0096] As a result, the transmit signal of band B is transmitted from RFIC 3 to antenna 2 via high-frequency input terminal 112, power amplifier 12, transmit filter 32, switching circuit 52, variable phase circuit 61, and antenna connection terminal 101. Conversely, the receive signal of band B is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 101, switching circuit 51, variable phase circuit 61, switching circuit 52, receive filter 42, low-noise amplifier 22, and high-frequency output terminal 122.

[0097] [3.4. Fourth Communication Mode]

[0098] First, refer to Figure 5 This will illustrate the fourth communication mode of high-frequency circuit 1. Figure 5 This is a circuit structure diagram showing the fourth communication mode of the high-frequency circuit 1 involved in this embodiment.

[0099] The fourth communication mode is a communication mode used to transmit signals in band C at a first power level (e.g., power level 2). In the fourth communication mode, the transmission of signals in the transmit band of band C is not simultaneous with the reception of signals in the receive band of band C.

[0100] In the fourth communication mode, the switching circuit 51 connects the common terminal 511 to the selection terminal 514, but not to the selection terminals 512 and 513. Furthermore, the switching circuit 53 connects the common terminal 531 to the selection terminal 533, but not to the selection terminal 532. Thus, one end of the transmitting filter 33 is connected to the antenna connection terminal 101 via the switching circuit 51, and the other end of the transmitting filter 33 is connected to the power amplifier 11 via the switching circuit 53.

[0101] As a result, the transmit signal of band C is transmitted from RFIC 3 to antenna 2 via high-frequency input terminal 111, power amplifier 11, switching circuit 53, transmit filter 33, switching circuit 51 and antenna connection terminal 101.

[0102] [3.5. Fifth Communication Mode]

[0103] Next, refer to Figure 6 This will illustrate the fifth communication mode of high-frequency circuit 1. Figure 6 This is a circuit structure diagram showing the fifth communication mode of the high-frequency circuit 1 involved in this embodiment.

[0104] The fifth communication mode is a communication mode used for transmitting and receiving signals in band C at a second power level (e.g., power level 3). In the fifth communication mode, the transmission of signals in the transmit band of band C is performed simultaneously with the reception of signals in the receive band of band C.

[0105] In the fifth communication mode, switch circuit 51 connects common terminal 511 to selection terminals 512 and 514, but not to selection terminal 513. Switch circuit 52 connects common terminal 521 to selection terminal 522, but not to selection terminal 523. Switch circuit 53 connects common terminal 531 to selection terminal 533, but not to selection terminal 532. Thus, one end of the transmitting filter 33 is connected to antenna connection terminal 101 via switch circuit 51, and the other end of the transmitting filter 33 is connected to power amplifier 11 via switch circuit 53. Furthermore, one end of the receiving filter 43 is connected to antenna connection terminal 101 via switch circuit 52, variable phase circuit 61, and switch circuit 51.

[0106] As a result, the transmit signal of band C is transmitted from RFIC 3 to antenna 2 via high-frequency input terminal 111, power amplifier 11, switching circuit 53, transmit filter 33, switching circuit 51, and antenna connection terminal 101. Conversely, the receive signal of band C is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 101, switching circuit 51, variable phase circuit 61, switching circuit 52, receive filter 43, low-noise amplifier 23, and high-frequency output terminal 123.

[0107] [4. Installation example of high-frequency circuit 1]

[0108] Next, refer to Figure 7 To illustrate the installation example of the high-frequency circuit 1 constructed as described above. Figure 7 This is a top view of the high-frequency circuit 1 according to this embodiment. Figure 7 In some cases, each component is labeled with a character (e.g., A-Tx) to make the configuration relationship between the components easier to understand, but the actual components may not be labeled with this character.

[0109] In addition, Figure 7 The illustration of a portion of the multiple circuit components included in the high-frequency circuit 1 is omitted. Circuit components not shown (such as power amplifiers 11 and 12) can be positioned at any location on the module substrate.

[0110] Module substrate 70 is a substrate used to mount high-frequency circuit 1. Figure 7 In the module substrate 70, transmitting filters 31 (A-Tx), 32 (B-Tx) and 33 (C-Tx), receiving filters 41 (A-Rx), 42 (B-Rx) and 43 (C-Rx), and integrated circuit 50 including switching circuits 51 (SW1) and 52 (SW2) are arranged on the main surface.

[0111] The module substrate 70 can be, for example, a low-temperature co-fired ceramic (LTCC) substrate or a high-temperature co-fired ceramic (HTCC) substrate with a multi-dielectric layer stacked structure, a component-embedded substrate, a substrate with a redistribution layer (RDL), or a printed circuit board, but is not limited to these.

[0112] Integrated circuit 50 is disposed between transmit filter 31 and receive filter 41, and between transmit filter 33 and receive filter 43. That is, the switching circuits 51 and 52 within integrated circuit 50 are disposed between transmit filter 31 and receive filter 41, and between transmit filter 33 and receive filter 43.

[0113] Within integrated circuit 50, switching circuit 51 is closer to transmitting filter 31 than switching circuit 52. That is, the distance D11 between switching circuit 51 and transmitting filter 31 is shorter than the distance D21 between switching circuit 52 and transmitting filter 31. Furthermore, within integrated circuit 50, switching circuit 52 is closer to receiving filter 41 than switching circuit 51. That is, the distance D22 between switching circuit 52 and receiving filter 41 is shorter than the distance D12 between switching circuit 51 and receiving filter 41.

[0114] The number of FETs (Field Effect Transistors) connected in series between the common terminal 511 and the select terminals 512 and 513 in switch circuit 51 is greater than the number of FETs connected in series between the common terminal 521 and the select terminals 522 and 523 in switch circuit 52. In other words, the number of stacks of individual series-connected SPST (Single-Pole Single-Throw) switches in switch circuit 51 is greater than the number of individual stacks of individual series-connected SPST switches in switch circuit 52.

[0115] In addition, Figure 7In this circuit, switching circuits 51 and 52 are mounted on a single integrated circuit 50, but are not limited to this. For example, switching circuits 51 and 52 may also be mounted separately on two integrated circuits.

[0116] [5. Summary]

[0117] As described above, the high-frequency circuit 1 according to this embodiment includes: a switching circuit 51, which includes a common terminal 511 connected to the antenna connection terminal 101, and selection terminals 512 and 513; a switching circuit 52, which includes a common terminal 521 connected to the selection terminal 512, and selection terminals 522 and 523; a transmit filter 31, which is connected to the selection terminal 513 and has a passband that includes a transmit band A that supports a first power level (e.g., power level 2) defined by a first maximum output power; a receive filter 41, which is connected to the selection terminal 522 and has a passband that includes a receive band A; and at least one of a transmit filter 32 and a receive filter 42 connected to the selection terminal 523, wherein the transmit filter 32 has a passband that includes a transmit band B that supports a second power level (e.g., power level 3) defined by a second maximum output power lower than the first maximum output power, and the receive filter 42 has a passband that includes a receive band B.

[0118] Accordingly, the receiving filter 41, and the receiving filter 42 and / or the transmitting filter 32 are connected to the switching circuit 51 via the switching circuit 52. Therefore, compared to the case where the receiving filter 41, and the receiving filter 42 and / or the transmitting filter 32 are directly connected to the selection terminals of the switching circuit 51, the number of selection terminals of the switching circuit 51 can be reduced. Consequently, the cutoff capacitance of the selection terminals in the switching circuit 51 can be reduced, and the loss of the transmitted signal in band A can be reduced.

[0119] Additionally, for example, in the high-frequency circuit 1 of this embodiment, when frequency band A is used for the first power level, the common terminal 511 may be connected to the selection terminal 513, and may not be connected to the selection terminal 512. When frequency band A is used for the second power level, the common terminal 511 may be connected to both the selection terminals 512 and 513, and the common terminal 521 may be connected to the selection terminal 522.

[0120] Accordingly, when frequency band A is used for the first power level, the common terminal 511 is not connected to the selection terminal 512. Therefore, the switching circuit 52 is not used to transmit the first power level signal, thus allowing the power tolerance of the switching circuit 52 to be lower than that of the switching circuit 51. As a result, the large size of the high-frequency circuit 1 caused by the switching circuit 52 can be suppressed, and the miniaturization of the high-frequency circuit 1 can be achieved by reducing the number of selection terminals of the switching circuit 51.

[0121] Alternatively, for example, in the high-frequency circuit 1 of this embodiment, the number of multiple FETs in the switching circuit 51 connected in series between the common terminal 511 and each of the selection terminals 512 and 513 may be greater than the number of multiple FETs in the switching circuit 52 connected in series between the common terminal 521 and each of the selection terminals 522 and 523.

[0122] Accordingly, the number of FETs in the switching circuit 51, which requires higher power tolerance, increases, resulting in a greater miniaturization effect due to the reduction of the select terminals of the switching circuit 51.

[0123] Additionally, for example, in the high-frequency circuit 1 according to this embodiment, the switching circuit 51 may also include a selection terminal 514, and the high-frequency circuit 1 may also include: a transmitting filter 33 connected to the selection terminal 514, having a passband that includes a transmitting frequency band supporting the first power level; and a receiving filter 43 connected to the selection terminal 522, having a passband that includes a receiving frequency band supporting the first power level.

[0124] Accordingly, the receiving filter 43 is further connected to the switching circuit 51 via the switching circuit 52. Therefore, compared to the case where the receiving filter 43 is directly connected to the selection terminal of the switching circuit 51, the number of selection terminals of the switching circuit 51 can be reduced. Consequently, the cutoff capacitance of the selection terminals in the switching circuit 51 can be reduced, thereby reducing the loss of the transmitted signal in band A as well as the loss of the transmitted signal in band C.

[0125] Additionally, for example, in the high-frequency circuit 1 of this embodiment, when frequency band C is used for the first power level, the common terminal 511 may be connected to the selection terminal 514, and may not be connected to the selection terminal 512. When frequency band C is used for the second power level, the common terminal 511 may be connected to both the selection terminals 512 and 514, and the common terminal 521 may be connected to the selection terminal 522.

[0126] Accordingly, when frequency band C is used for the first power level, the common terminal 511 is not connected to the selection terminal 512. Therefore, the switching circuit 52 is not used to transmit the first power level signal, thus allowing the power tolerance of the switching circuit 52 to be lower than that of the switching circuit 51. As a result, the large size of the high-frequency circuit 1 caused by the switching circuit 52 can be suppressed, and the miniaturization of the high-frequency circuit 1 can be achieved by reducing the number of selection terminals of the switching circuit 51.

[0127] Alternatively, for example, the high-frequency circuit 1 according to this embodiment may also include a variable phase circuit 61 connected between the selection terminal 512 and the common terminal 521.

[0128] Accordingly, the phase shift of the variable phase circuit 61 can be changed when both transmission and reception of signals in frequency band A and frequency band C are performed simultaneously. Therefore, when both transmission and reception of signals in frequency band A are performed simultaneously, the phase shift of the variable phase circuit 61 can be adjusted to a level that makes the impedance of the transmission band of frequency band A close to an open circuit when viewed from the common terminal 511 and the receiving filter 41. Furthermore, when both transmission and reception of signals in frequency band C are performed simultaneously, the phase shift of the variable phase circuit 61 can be adjusted to a level that makes the impedance of the transmission band of frequency band C close to an open circuit when viewed from the common terminal 511 and the receiving filter 43. As a result, intermodulation distortion caused by leakage of the transmitted signal into the receiving path during simultaneous transmission and reception of signals in frequency band A and frequency band C can be suppressed.

[0129] Additionally, for example, the high-frequency circuit 1 according to this embodiment may also include: a power amplifier 11; and a switching circuit 53, which includes a common terminal 531 connected to the power amplifier 11, a selection terminal 532 connected to the transmitting filter 31, and a selection terminal 533 connected to the transmitting filter 33.

[0130] Accordingly, the power amplifier 11 can be used to amplify the transmitted signals of frequency bands A and C, and the circuit size of the high-frequency circuit 1 can be reduced compared to the case where power amplifiers are prepared separately for frequency bands A and C.

[0131] Additionally, for example, in the high-frequency circuit 1 involved in this embodiment, frequency band A may be Band 1 for LTE or n1 for 5G NR, frequency band B may be Band 25 for LTE or n25 for 5G NR, and frequency band C may be Band 3 for LTE or n3 for 5G NR.

[0132] Accordingly, the high-frequency circuit 1 can support the transmission and reception of signals for Band 1 of LTE or n1 of 5G NR, the transmission and reception of signals for Band 25 of LTE or n25 of 5G NR, and the transmission and reception of signals for Band 3 of LTE or n3 of 5G NR.

[0133] Alternatively, for example, the high-frequency circuit 1 involved in this embodiment may also include a module substrate 70 configured with switching circuits 51 and 52, as well as a transmitting filter 31 and a receiving filter 41. Switching circuits 51 and 52 may also be configured between the transmitting filter 31 and the receiving filter 41. Switching circuit 51 may be closer to the transmitting filter 31 than switching circuit 52, and switching circuit 52 may be closer to the receiving filter 41 than switching circuit 51.

[0134] Accordingly, the transmitting filter 31, which is directly connected to the switching circuit 51, can be positioned near the switching circuit 51, and the receiving filter 41, which is directly connected to the switching circuit 52, can be positioned near the switching circuit 52. As a result, the wiring length between the switching circuit 51 and the transmitting filter 31, as well as the wiring length between the switching circuit 52 and the receiving filter 41, can be shortened.

[0135] Alternatively, for example, in the high-frequency circuit 1 according to this embodiment, the switching circuit 51 may be mounted via CMOS-SOI.

[0136] Therefore, the power handling capability of the switching circuit 51 can be improved, and the miniaturization of the switching circuit 51 can be achieved.

[0137] (Other implementation methods)

[0138] The above description of the high-frequency circuit according to the present invention is based on embodiments; however, the high-frequency circuit according to the present invention is not limited to the above embodiments. Other embodiments implemented by combining any structural elements in the above embodiments, variations of the above embodiments that can be conceived by those skilled in the art without departing from the spirit of the present invention, and various devices incorporating the above high-frequency circuit are also included in the present invention.

[0139] For example, in the circuit structure of the high-frequency circuits according to the above embodiments, other circuit elements and wiring may be inserted between the paths connecting the circuit elements and signal paths disclosed in the drawings. For example, an impedance matching circuit may be inserted between the filter and the switching circuit.

[0140] Additionally, for example, the high-frequency circuits described in the above embodiments may also include one or more transmit filters and / or receive filters. In this case, the switching circuits 51 and / or 52 may also include one or more additional selection terminals for connecting one or more transmit filters and / or receive filters.

[0141] The features of the high-frequency circuit described below based on the above embodiments are shown below.

[0142] <1>

[0143] A high-frequency circuit, comprising:

[0144] The first switching circuit includes a first common terminal connected to the antenna connection terminal, a first selection terminal and a second selection terminal;

[0145] The second switching circuit includes a second common terminal connected to the first selection terminal, as well as a third selection terminal and a fourth selection terminal;

[0146] A first transmit filter, connected to the second select terminal, has a passband that includes a transmit band supporting a first FDD band with a first power level defined by a first maximum output power;

[0147] A first receiving filter, connected to the third selection terminal, has a passband that includes the receiving frequency band of the first FDD band; and

[0148] At least one of a second transmitting filter and a second receiving filter connected to the fourth selection terminal, the second transmitting filter having a passband that includes a transmitting band supporting a second power level defined by a second maximum output power lower than the first maximum output power, and the second receiving filter having a passband that includes a receiving band that includes a third frequency band.

[0149] <2>

[0150] according to <1> The high-frequency circuit, wherein,

[0151] When the first FDD frequency band is used for the first power level, the first common terminal is connected to the second select terminal, but not to the first select terminal.

[0152] When the first FDD band is used for the second power level, the first common terminal is connected to the first select terminal and the second select terminal, and the second common terminal is connected to the third select terminal.

[0153] <3>

[0154] according to <1> or <2> The high-frequency circuit, wherein,

[0155] The number of FETs in the first switching circuit that are connected in series between the first common terminal and each of the first and second selection terminals is greater than the number of FETs in the second switching circuit that are connected in series between the second common terminal and each of the third and fourth selection terminals.

[0156] <4>

[0157] according to <1> ~ <3> The high-frequency circuit described in any one of the above, wherein,

[0158] The first switching circuit also has a fifth selection terminal.

[0159] The high-frequency circuit also features:

[0160] A third transmit filter, connected to the fifth selection terminal, has a passband including a transmit band supporting a fourth FDD band of the first power level; and

[0161] The third receiving filter, which is connected to the third selection terminal, has a passband that includes the receiving frequency band of the fourth FDD band.

[0162] <5>

[0163] according to <4> The high-frequency circuit, wherein,

[0164] When the fourth FDD band is used for the first power level, the first common terminal is connected to the fifth select terminal, but not to the first select terminal.

[0165] When the fourth FDD band is used for the second power level, the first common terminal is connected to the first selection terminal and the fifth selection terminal, and the second common terminal is connected to the third selection terminal.

[0166] <6>

[0167] according to <4> or <5> The high-frequency circuit, wherein,

[0168] The high-frequency circuit also includes a variable phase circuit connected between the first selection terminal and the second common terminal.

[0169] <7>

[0170] according to <4> ~ <6> The high-frequency circuit described in any one of the above, wherein,

[0171] The high-frequency circuit also features:

[0172] Power amplifiers; and

[0173] The third switching circuit includes a third common terminal connected to the power amplifier, a sixth selection terminal connected to the first transmitting filter, and a seventh selection terminal connected to the third transmitting filter.

[0174] <8>

[0175] according to <4> ~ <7> The high-frequency circuit described in any one of the above, wherein,

[0176] The first FDD band is Band 1 for LTE or n1 for 5G NR.

[0177] Both the second and third frequency bands are Band 25 for LTE or n25 for 5G NR.

[0178] The fourth FDD band is Band3 for LTE or n3 for 5G NR.

[0179] <9>

[0180] according to <1> ~ <8> The high-frequency circuit described in any one of the above, wherein,

[0181] The high-frequency circuit also includes a module substrate configured with the first switching circuit, the second switching circuit, the first transmitting filter, and the first receiving filter.

[0182] The first switching circuit and the second switching circuit are configured between the first transmitting filter and the first receiving filter.

[0183] The first switching circuit is closer to the first transmitting filter than the second switching circuit.

[0184] The second switching circuit is closer to the first receiving filter than the first switching circuit.

[0185] <10>

[0186] according to <1> ~ <9> The high-frequency circuit described in any one of the above, wherein,

[0187] The first switching circuit is mounted via CMOS-SOI.

[0188] Industrial availability

[0189] As a high-frequency circuit configured in the front end, this invention can be widely used in communication devices such as portable telephones.

[0190] Explanation of reference numerals in the attached figures

[0191] 1: High-frequency circuits

[0192] 2: Antenna

[0193] 3: RFIC

[0194] 4: BBIC

[0195] 5: Communication device

[0196] 11, 12: Power Amplifier

[0197] 21, 22, 23: Low-noise amplifiers

[0198] 31, 32, 33: Transmit filters

[0199] 41, 42, 43: Receiver filters

[0200] 50: Integrated Circuits

[0201] 51, 52, 53: Switching circuits

[0202] 61: Variable phase circuit

[0203] 70: Module baseboard

[0204] 101: Antenna connection terminal

[0205] 111, 112: High-frequency input terminals

[0206] 121, 122, 123: High-frequency output terminals

[0207] 511, 521, 531: Common terminals

[0208] 512, 513, 514, 522, 523, 532, 533: Select terminal

[0209] D11, D12, D21, D22: Distance

Claims

1. A high-frequency circuit, comprising: The first switching circuit includes a first common terminal connected to the antenna connection terminal, a first selection terminal and a second selection terminal; The second switching circuit includes a second common terminal connected to the first selection terminal, as well as a third selection terminal and a fourth selection terminal; A first transmitting filter, connected to the second selection terminal, has a passband that includes a transmitting band that supports a first frequency division duplex band, i.e., a first FDD band, which is a first power level defined by a first maximum output power. A first receiving filter, which is connected to the third selection terminal, has a passband that includes the receiving frequency band of the first FDD band; as well as At least one of a second transmitting filter and a second receiving filter connected to the fourth selection terminal, the second transmitting filter having a passband that includes a transmitting band supporting a second power level defined by a second maximum output power lower than the first maximum output power, and the second receiving filter having a passband that includes a receiving band that includes a third frequency band.

2. The high-frequency circuit according to claim 1, wherein, When the first FDD frequency band is used for the first power level, the first common terminal is connected to the second select terminal, but not to the first select terminal. When the first FDD band is used for the second power level, the first common terminal is connected to the first select terminal and the second select terminal, and the second common terminal is connected to the third select terminal.

3. The high-frequency circuit according to claim 1 or 2, wherein, The number of field-effect transistors (FETs) in the first switching circuit that are connected in series between the first common terminal and each of the first and second selection terminals is greater than the number of FETs in the second switching circuit that are connected in series between the second common terminal and each of the third and fourth selection terminals.

4. The high-frequency circuit according to any one of claims 1 to 3, wherein, The first switching circuit also has a fifth selection terminal. The high-frequency circuit also features: A third transmit filter, connected to the fifth selection terminal, has a passband including a transmit band supporting a fourth FDD band of the first power level; and The third receiving filter, which is connected to the third selection terminal, has a passband that includes the receiving frequency band of the fourth FDD band.

5. The high-frequency circuit according to claim 4, wherein, When the fourth FDD band is used for the first power level, the first common terminal is connected to the fifth select terminal, but not to the first select terminal. When the fourth FDD band is used for the second power level, the first common terminal is connected to the first selection terminal and the fifth selection terminal, and the second common terminal is connected to the third selection terminal.

6. The high-frequency circuit according to claim 4 or 5, wherein, The high-frequency circuit also includes a variable phase circuit connected between the first selection terminal and the second common terminal.

7. The high-frequency circuit according to any one of claims 4 to 6, wherein, The high-frequency circuit also features: Power amplifiers; and The third switching circuit includes a third common terminal connected to the power amplifier, a sixth selection terminal connected to the first transmitting filter, and a seventh selection terminal connected to the third transmitting filter.

8. The high-frequency circuit according to any one of claims 4 to 7, wherein, The first FDD band is Band 1 for LTE or n1 for 5G NR. Both the second and third frequency bands are Band 25 for LTE or n25 for 5G NR. The fourth FDD band is Band3 for LTE or n3 for 5G NR.

9. The high-frequency circuit according to any one of claims 1 to 8, wherein, The high-frequency circuit also includes a module substrate configured with the first switching circuit, the second switching circuit, the first transmitting filter, and the first receiving filter. The first switching circuit and the second switching circuit are configured between the first transmitting filter and the first receiving filter. The first switching circuit is closer to the first transmitting filter than the second switching circuit. The second switching circuit is closer to the first receiving filter than the first switching circuit.

10. The high-frequency circuit according to any one of claims 1 to 9, wherein, The first switching circuit is mounted via complementary metal-oxide-semiconductor-silicon-on-insulator (CMOS-SOI).

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