High frequency circuit and communication device

Abstract

The high-frequency circuit (1) is capable of performing MIMO transmission in band A and uplink CA in bands A and B, and includes: a power amplifier (21) that amplifies the signal in band A; a power amplifier (22) that amplifies the signals in bands A and B; a filter (11) whose passband includes band A; a filter (12) whose passband includes band B; a filter (13) whose passband includes band A; and a switch (32) that simultaneously executes the terminal (3). 2a) Connection to terminal (32c) and connection between terminal (32b) and terminal (32d), while simultaneously performing connection between terminal (32a) and terminal (32c) and connection between terminal (32b) and terminal (32e), wherein terminal (32a) is connected to power amplifier (21), terminal (32b) is connected to power amplifier (22), terminal (32c) is connected to filter (11), terminal (32d) is connected to filter (12), and terminal (32e) is connected to filter (13).

Description

Technical Field

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

[0002] In communication terminals such as portable telephones, MIMO (Multiple Input Multiple Output) is used. MIMO is a technology that improves communication speed by using multiple antennas to transmit and receive multiple signals in a spatially multiplexed manner.

[0003] Patent Document 1 discloses a high-frequency module having a first circuit for primary or diversity use and a second circuit for MIMO use.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: International Publication No. 2019 / 065419 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] However, in the high-frequency module (high-frequency circuit) disclosed in Patent Document 1, power amplifiers are independently configured for the second circuit used for MIMO and the first circuit used for main or diversity purposes, which leads to the problem of increased circuit size and larger high-frequency circuit.

[0009] Therefore, the present invention was made to solve the above-mentioned problems, and its object is to provide a small high-frequency circuit and communication device capable of transmitting high-frequency signals of MIMO and non-MIMO.

[0010] Solution for solving the problem

[0011] One aspect of the present invention relates to a high-frequency circuit capable of simultaneously transmitting signals in a first frequency band and signals in a second frequency band, as well as uplink MIMO in the first frequency band. The high-frequency circuit includes: a first power amplifier capable of amplifying signals in the first frequency band; a second power amplifier capable of amplifying signals in both the first and second frequency bands; a first filter whose passband includes at least a portion of the first frequency band; a second filter whose passband includes at least a portion of the second frequency band; and a third filter, different from the first filter, whose passband includes... The device includes at least a portion of a first frequency band; and a first switch having a first terminal, a second terminal, a third terminal, a fourth terminal, and a fifth terminal, capable of simultaneously performing a connection between the first terminal and the third terminal and a connection between the second terminal and the fourth terminal, and simultaneously performing a connection between the first terminal and the third terminal and a connection between the second terminal and the fifth terminal, wherein the first terminal is connected to the output terminal of a first power amplifier, the second terminal is connected to the output terminal of a second power amplifier, the third terminal is connected to a first filter, the fourth terminal is connected to a second filter, and the fifth terminal is connected to a third filter.

[0012] The effects of the invention

[0013] According to the present invention, a small high-frequency circuit and communication device capable of transmitting high-frequency signals of both MIMO and non-MIMO can be provided. Attached Figure Description

[0014] Figure 1 This is a circuit structure diagram of the high-frequency circuit and communication device involved in Embodiment 1.

[0015] Figure 2 This is a circuit diagram of the high-frequency circuit and communication device involved in the comparative example.

[0016] Figure 3 This is a circuit state diagram of the dual uplink CA (Carrier Aggregation) of the high-frequency circuit and communication device involved in Implementation Method 1.

[0017] Figure 4 This is a circuit state diagram of the uplink 2×2 MIMO of the high-frequency circuit and communication device involved in Implementation Method 1.

[0018] Figure 5 This is a diagram showing the module structure of the high-frequency circuit involved in Implementation Method 1.

[0019] Figure 6A This is a circuit structure diagram of the high-frequency circuit and communication device involved in a variation of Embodiment 1.

[0020] Figure 6BThis is a Smith chart showing the output impedance of the power amplifier involved in the variation of Embodiment 1.

[0021] Figure 7 This is a circuit structure diagram of the high-frequency circuit and communication device involved in Embodiment 2.

[0022] Figure 8 This is a circuit state diagram of the dual uplink ENDC (Eutra NRDual Connectivity: Dual Connectivity of Terrestrial Radio Access and New Radio) of the high-frequency circuit and communication device involved in Implementation Method 2.

[0023] Figure 9 This is a circuit state diagram of the dual uplink CA of the high-frequency circuit and communication device involved in Implementation Method 2.

[0024] Figure 10 This is a circuit state diagram of the high-frequency circuit and communication device involved in Implementation 2, which has dual uplink CA and uplink 2×2 MIMO.

[0025] Figure 11 This is a circuit state diagram of the uplink 4×4 MIMO of the high-frequency circuit and communication device involved in Embodiment 2. Detailed Implementation

[0026] 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.

[0027] 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.

[0028] In this disclosure, "connection" means not only direct connection using connection terminals and / or wiring conductors, but also electrical connection via other circuit elements. Furthermore, "connected between A and B" and "connected between A and B" mean connected to A and B along the path that connects A and B.

[0029] In addition, in this disclosure, "transmission path" refers to a transmission line consisting of wiring for transmitting high-frequency transmission signals, electrodes directly connected to the wiring, and terminals directly connected to the wiring or the electrodes.

[0030] Additionally, in this disclosure, "component disposed on substrate" includes: component disposed on the main surface of substrate; component disposed within substrate; and component disposed on the main surface side in a manner that does not contact the main surface (e.g., component stacked on other components disposed in contact with the main surface).

[0031] (Implementation Method 1)

[0032] [1 Circuit structure of high-frequency circuit 1 and communication device 4]

[0033] Reference Figure 1 The circuit structure of the high-frequency circuit 1 and the communication device 4 involved in this embodiment will be explained. Figure 1 This is a circuit structure diagram of the high-frequency circuit 1 and the communication device 4 involved in Embodiment 1.

[0034] [1.1 Circuit structure of communication device 4]

[0035] First, the circuit structure of communication device 4 will be explained. For example... Figure 1 As shown, the communication device 4 according to this embodiment includes a high-frequency circuit 1, antennas 2a and 2b, and an RF signal processing circuit (RFIC) 3.

[0036] High-frequency circuit 1 transmits high-frequency signals between antennas 2a and 2b and RFIC 3. The detailed circuit structure of high-frequency circuit 1 will be described later.

[0037] Antennas 2a and 2b are examples of the first antenna and the second antenna, respectively. They are connected to the switch 31 of the high-frequency circuit 1 to transmit high-frequency signals output from the high-frequency circuit 1. In addition, they receive high-frequency signals from the outside and output the high-frequency signals to the high-frequency circuit 1.

[0038] RFIC 3 is an example of a signal processing circuit that processes high-frequency signals. Specifically, RFIC 3 processes the received signal input via the receiving path of high-frequency circuit 1 using down-conversion or the like, and outputs the resulting received signal to the baseband signal processing circuit (BBIC: not shown). Additionally, RFIC 3 processes the transmitted signal input from the BBIC using up-conversion or the like, and outputs the resulting transmitted signal to the transmitting path of high-frequency circuit 1. Furthermore, RFIC 3 has a control unit that controls the switches and amplifiers in high-frequency circuit 1. Moreover, some or all of the functions of the control unit in RFIC 3 can be installed externally, for example, on the BBIC or high-frequency circuit 1.

[0039] RFIC 3 has terminals 30a, 30b, and 30c. Terminal 30a faces the high-frequency circuit 1 and outputs the main signal and MIMO signal for frequency band A. Terminal 30b faces the high-frequency circuit 1 and outputs the main signal for frequency band B. Terminal 30c faces the high-frequency circuit 1 and outputs the MIMO signal for frequency band A.

[0040] Furthermore, in the communication device 4 according to this embodiment, antennas 2a and 2b are not essential structural elements.

[0041] [1.2 Circuit Structure of High-Frequency Circuit 1]

[0042] Next, the circuit structure of high-frequency circuit 1 will be described. For example... Figure 1 As shown, the high-frequency circuit 1 includes filters 11, 12 and 13, power amplifiers 21 and 22, and switches 31, 32 and 33.

[0043] Filter 11 is an example of a first filter, the passband of which includes at least a portion of frequency band A (first frequency band). Filter 11 is connected between switches 31 and 32.

[0044] Filter 12 is an example of a second filter, the passband of which includes at least a portion of frequency band B (second frequency band). Filter 12 is connected between switches 31 and 32.

[0045] Filter 13 is an example of a third filter, and its passband includes at least a portion of frequency band A (first frequency band). Filter 13 differs from filter 11. Filter 13 is connected between switches 31 and 32.

[0046] Furthermore, when frequency band A is used for frequency division duplex (FDD), the passbands of filters 11 and 13 each include the uplink operating frequency band of frequency band A. Additionally, when frequency band A is used for time division duplex (TDD), the passbands of filters 11 and 13 each include frequency band A.

[0047] Furthermore, when frequency band B is used for FDD, the passband of filter 12 includes the uplink operating frequency band of frequency band B. Also, when frequency band B is used for TDD, the passband of filter 12 includes frequency band B.

[0048] Furthermore, the uplink operating frequency band refers to the frequency range designated for uplink use within the aforementioned frequency bands. Conversely, the downlink operating frequency band refers to the frequency range designated for downlink use within the aforementioned frequency bands.

[0049] Power amplifier 21 is an example of the first power amplifier, capable of amplifying the transmitted signal of frequency band A input from RFIC 3 via switch 33. Power amplifier 21 is connected between switches 32 and 33.

[0050] Power amplifier 22 is an example of a second power amplifier, capable of amplifying the transmitted signals of frequency bands A and B input from RFIC 3 via switch 33. Power amplifier 22 is connected between switches 32 and 33.

[0051] Furthermore, frequency bands A and B refer to frequency bands predefined by standardization organizations (such as 3GPP, IEEE (Institute of Electrical and Electronics Engineers), etc.) for communication systems built using Radio Access Technology (RAT). In this embodiment, as a communication system, systems such as 4G (4th Generation)-LTE (Long Term Evolution), 5G (5th Generation)-NR (New Radio), and WLAN (Wireless Local Area Network) can be used, but are not limited to them.

[0052] Frequency band A, for example, belongs to the high-frequency band group (2.4 GHz - 2.8 GHz), and frequency band B, for example, belongs to the mid-frequency band group (1.5 GHz - 2.4 GHz). In particular, frequency band A is, for example, Band 41 (2496 MHz - 2690 MHz), and frequency band B is, for example, Band 40 (2300 MHz - 2400 MHz).

[0053] Switch 32 is an example of the first switch, and has terminals 32a (first terminal), 32b (second terminal), 32c (third terminal), 32d (fourth terminal), and 32e (fifth terminal). Terminal 32a is connected to the output terminal of power amplifier 21, terminal 32b is connected to the output terminal of power amplifier 22, terminal 32c is connected to the input terminal of filter 11, terminal 32d is connected to the input terminal of filter 12, and terminal 32e is connected to the input terminal of filter 13.

[0054] The switch 32 has a multi-connection structure capable of simultaneously connecting terminals 32a and 32c, and terminals 32b and 32d, and also capable of simultaneously connecting terminals 32a and 32c, and terminals 32b and 32e. The switch 32 is, for example, a DP3T (Double Pole 3Throw) type switch circuit.

[0055] Switch 33 is an example of the second switch, having terminals 33a (terminal 6), 33b (terminal 7), 33c (terminal 8), 33d (terminal 9), and 33e (terminal 10). Terminal 33a is connected to the input terminal of power amplifier 21, and terminal 33b is connected to the input terminal of power amplifier 22. Terminal 33c is connected to terminal 30a of RFIC 3, and terminal 33c receives the main signal or MIMO signal of frequency band A. Terminal 33d is connected to terminal 30b of RFIC 3, and terminal 33d receives the main signal of frequency band B. Terminal 33e is connected to terminal 30c of RFIC 3, and terminal 33e receives the MIMO signal of frequency band A.

[0056] The switch 33 has a multi-connection type structure capable of simultaneously connecting terminals 33a and 33c, and terminals 33b and 33d, and also capable of simultaneously connecting terminals 33a and 33c, and terminals 33b and 33e. The switch 33 is, for example, a DP3T type switch circuit.

[0057] Switch 31 is an example of the third switch, and has terminals 31a (first antenna connection terminal), 31b (second antenna connection terminal), 31c (16th terminal), 31d (17th terminal), and 31e (18th terminal). Terminal 31a is connected to antenna 2a, terminal 31b is connected to antenna 2b, terminal 31c is connected to the output terminal of filter 11, terminal 31d is connected to the output terminal of filter 12, and terminal 31e is connected to the output terminal of filter 13.

[0058] The switch 31 has a multi-connection type structure capable of simultaneously connecting terminals 31a and 31c, and terminals 31b and 31d, and also capable of simultaneously connecting terminals 31a and 31c, and terminals 31b and 31e. The switch 31 is, for example, a DP3T type switch circuit.

[0059] Furthermore, switch 32 can also be formed within a semiconductor IC (Integrated Circuit). Switches 31 and 33 can also be included within the aforementioned semiconductor IC. This allows for the miniaturization and reduction in the height of switches 31, 32, and 33. The semiconductor IC is, for example, constructed using CMOS (Complementary Metal Oxide Semiconductor). Specifically, it is formed using SOI (Silicon-on-Insulator) technology. This allows for the inexpensive manufacture of the semiconductor IC. Furthermore, the semiconductor IC can also be constructed from at least any one of GaAs, SiGe, and GaN. This enables the output of high-frequency signals with high-quality amplification and noise reduction performance.

[0060] According to the above structure, the high-frequency circuit 1 and the communication device 4 can perform simultaneous transmission of signals in frequency band A and frequency band B, as well as uplink MIMO in frequency band A. Simultaneous transmission of signals in frequency band A and frequency band B, and uplink MIMO in frequency band A, are achieved, for example, by multiple-connection switches 31 to 33.

[0061] [1.3 Circuit Structure of the High-Frequency Circuit and Communication Device Involved in the Comparative Examples]

[0062] Here, the circuit structure of a comparative example equivalent to the prior art will be described in advance. Figure 2 This is a circuit diagram of the high-frequency circuit 301 and the communication device 304 involved in the comparative example. The communication device 304 includes the high-frequency circuit 301, antennas 2a and 2b, and RFIC 3. Compared with the communication device 4 involved in Embodiment 1, the communication device 304 involved in the comparative example has a different circuit structure in the high-frequency circuit 301. The high-frequency circuit 301 includes filters 11, 12, and 13, power amplifiers 21, 322, and 323, and switches 31, 332, and 333. The high-frequency circuit 301 involved in the comparative example differs from the high-frequency circuit 1 involved in Embodiment 1 in that it has three power amplifiers and the connection structure between the three power amplifiers and the switches is different. Hereinafter, regarding the high-frequency circuit 301 involved in the comparative example, the description of its structure that is the same as that of the high-frequency circuit 1 involved in Embodiment 1 will be omitted, and the description will focus on the differences.

[0063] Power amplifier 21 amplifies the transmitted signal of frequency band A input from RFIC 3 via switch 333. Power amplifier 21 is connected between switches 332 and 333.

[0064] Power amplifier 322 amplifies the transmitted signal of frequency band B input from RFIC 3 via switch 333. Power amplifier 322 is connected between switches 332 and 333.

[0065] Power amplifier 323 amplifies the transmitted signal of frequency band A input from RFIC 3. Power amplifier 323 is not connected to switches 332 and 333, but is connected between filter 13 and RFIC 3.

[0066] Switch 332 has four terminals. The first terminal of switch 332 is connected to the output terminal of power amplifier 21, the second terminal of switch 332 is connected to the output terminal of power amplifier 322, the third terminal of switch 332 is connected to the input terminal of filter 11, and the fourth terminal of switch 332 is connected to the input terminal of filter 12.

[0067] The switch 332 has a structure that enables simultaneous connection of the first terminal to the third terminal and connection of the second terminal to the fourth terminal.

[0068] Switch 333 has four terminals. Terminal 1 of switch 333 is connected to the input terminal of power amplifier 21, and terminal 2 of switch 333 is connected to the input terminal of power amplifier 322. Terminal 333 is connected to terminal 30a of RFIC 3, and this terminal receives the main signal or MIMO signal for frequency band A. Terminal 4 of switch 333 is connected to terminal 30b of RFIC 3, and this terminal receives the main signal for frequency band B.

[0069] The switch 333 has a structure that enables simultaneous connection of the first terminal to the third terminal and connection of the second terminal to the fourth terminal.

[0070] The input terminal of power amplifier 323 is connected to terminal 30c of RFIC 3, and the output terminal of power amplifier 323 is connected to the input terminal of filter 13. Power amplifier 323 is supplied with MIMO signals in frequency band A.

[0071] According to the above structure, the high-frequency circuit 301 and the communication device 304 can perform simultaneous transmission of signals in frequency band A and frequency band B, as well as uplink MIMO transmission in frequency band A.

[0072] In the high-frequency circuit 301 involved in the comparative example, the power amplifier 322 only amplifies frequency band B in frequency bands A and B, so another power amplifier 323 is needed to amplify the MIMO signal in frequency band A.

[0073] In contrast, in the high-frequency circuit 1 according to Embodiment 1, the power amplifier 22 serves as both a power amplifier for amplifying the MIMO signal in frequency band A and a power amplifier for amplifying the main signal in frequency band B. This reduces the number of power amplifiers in the high-frequency circuit 1, thus enabling miniaturization of the high-frequency circuit 1.

[0074] [1.4 Circuit Connection Status of High-Frequency Circuit 1]

[0075] Next, the circuit connection state of the high-frequency circuit 1 corresponding to the signal transmission mode will be explained. The signal transmission modes that the high-frequency circuit 1 involved in this embodiment can perform are: (1) separate transmission of the main signal of frequency band A; (2) separate transmission of the main signal of frequency band B; (3) simultaneous transmission of the main signal of frequency band A and the main signal of frequency band B (dual uplink CA); and (4) MIMO transmission of frequency band A (uplink 2×2 MIMO).

[0076] Figure 3 This is a circuit state diagram of the dual uplink CA of the high-frequency circuit 1 and the communication device 4 involved in Embodiment 1. Additionally, Figure 4 This is a circuit state diagram of the uplink 2×2 MIMO of the high-frequency circuit 1 and the communication device 4 involved in Implementation Method 1.

[0077] First, in the case of transmitting the main signal of frequency band A alone in (1), Figure 1 In this configuration, terminals 33a and 33c are connected, terminals 32a and 32c are connected, and terminals 31a and 31c are connected. At this time, the transmission signal of frequency band A is transmitted through the transmission path of RFIC 3, switch 33, power amplifier 21, switch 32, filter 11, switch 31, and antenna 2a.

[0078] Next, in the case of transmitting the main signal of frequency band B separately in (2), Figure 1 In this configuration, terminals 33b and 33d are connected, terminals 32b and 32d are connected, and terminals 31a and 31d are connected. At this time, the transmitted signal for frequency band B is transmitted through the following transmission path: RFIC 3, switch 33, power amplifier 22, switch 32, filter 12, switch 31, and antenna 2a.

[0079] Next, in the case of dual uplink CA of the main signal in frequency band A and the main signal in frequency band B, such as Figure 3As shown, terminals 33a and 33c are connected, terminals 32a and 32c are connected, and terminals 31a and 31c are connected. Simultaneously, terminals 33b and 33d are connected, terminals 32b and 32d are connected, and terminals 31b and 31d are connected. At this time, the main signal of frequency band A is transmitted through the transmission path of RFIC 3, switch 33, power amplifier 21, switch 32, filter 11, switch 31, and antenna 2a. Simultaneously, the main signal of frequency band B is transmitted through the transmission path of RFIC 3, switch 33, power amplifier 22, switch 32, filter 12, switch 31, and antenna 2b.

[0080] Next, in the case of MIMO transmission in band A (4) (uplink 2×2 MIMO), as follows Figure 4 As shown, terminals 33a and 33c are connected, terminals 32a and 32c are connected, and terminals 31a and 31c are connected. Simultaneously, terminals 33b and 33e are connected, terminals 32b and 32e are connected, and terminals 31b and 31e are connected. At this time, the MIMO signal of frequency band A is transmitted through the transmission path of RFIC 3, switch 33, power amplifier 21, switch 32, filter 11, switch 31, and antenna 2a. Simultaneously, the MIMO signal of frequency band A is transmitted through the transmission path of RFIC 3, switch 33, power amplifier 22, switch 32, filter 13, switch 31, and antenna 2b.

[0081] Furthermore, in switch 32, when terminals 32b and 32e are connected, terminals 32a and 32c are always connected. Similarly, in switch 33, when terminals 33b and 33e are connected, terminals 33a and 33c are always connected. Filter 13 is a dedicated filter for 2×2 MIMO; therefore, when filter 13 is used, filter 11 is always used as a filter for 2×2 MIMO.

[0082] [1.5 Module Structure of High-Frequency Circuit 1]

[0083] In the high-frequency circuit 1 of this embodiment, power amplifiers 21 and 22 and switch 32 are disposed on the same first substrate.

[0084] Accordingly, the signal wiring connecting power amplifiers 21 and 22 to switch 32 can be shortened, thus reducing transmission losses of the high-power transmitted signals output from power amplifiers 21 and 22. Therefore, the power consumption of high-frequency circuit 1 can be reduced.

[0085] Furthermore, switches 31 and 33 can also be disposed together with switch 32 on the first substrate. Alternatively, switches 31, 32, and 33 can be included in the same semiconductor IC. This allows for miniaturization of the high-frequency circuit 1.

[0086] In addition, such as Figure 5 As shown in the module structure of the high-frequency circuit 1, in the high-frequency circuit 1, in addition to arranging power amplifiers 21 and 22 and switches 31 to 33 on the first substrate, filters 11 and 12 may also be arranged on the first substrate. On the other hand, filter 13 may also be arranged on a second substrate different from the first substrate. Accordingly, by switching the electrical connection and non-connection between the first substrate and the second substrate, the high-frequency circuit 1 can be used as a MIMO-enabled module that enables filter 13 to function, and as a main module that does not enable filter 13 to function.

[0087] Alternatively, in the high-frequency circuit 1 according to this embodiment, in addition to arranging power amplifiers 21 and 22 and switches 31 to 33 on the first substrate, filters 11 to 13 may also be arranged on the first substrate. Accordingly, the high-frequency circuit 1 can be used as a small module capable of performing MIMO.

[0088] Accordingly, the transmission path from power amplifiers 21 and 22 to switch 31 can be shortened, thus further reducing the transmission loss of the high-power transmission signal output from power amplifiers 21 and 22. In addition, the high-frequency circuit 1 can be miniaturized.

[0089] [1.6 Circuit structure of high-frequency circuit 1A involved in the modified example]

[0090] Figure 6A This is a circuit diagram of the high-frequency circuit 1A and the communication device 4A according to a modification of Embodiment 1. The communication device 4A includes the high-frequency circuit 1A, antennas 2a and 2b, and RFIC 3. The high-frequency circuit 1A of the communication device 4A according to this modification differs from the communication device 4 according to Embodiment 1 in its circuit structure. The high-frequency circuit 1A includes filters 11, 12, and 13, power amplifiers 21 and 22, switches 31, 32, and 33, and matching circuits 41 and 42. The high-frequency circuit 1A according to this modification differs from the high-frequency circuit 1 according to Embodiment 1 in that it includes matching circuits 41 and 42. Hereinafter, the description of the high-frequency circuit 1A according to this modification, which shares the same structure as the high-frequency circuit 1 according to Embodiment 1, will be omitted, and the description will focus on the differences.

[0091] Matching circuit 41 is an example of a first matching circuit with variable impedance, connected between power amplifier 21 and switch 32. Matching circuit 41 includes at least one of an inductor and a capacitor.

[0092] Matching circuit 42 is an example of a second matching circuit with variable impedance, connected between power amplifier 22 and switch 32. Matching circuit 42 includes at least one of an inductor and a capacitor.

[0093] Figure 6B This is a Smith chart showing the output-side impedances of power amplifiers 21 and 22 according to a variation of Embodiment 1. The chart illustrates the relationship between the output-side impedance of power amplifier 21 (impedance viewed from the output terminals of power amplifier 21) and the efficiency and ACLR (adjacent-channel leakage power ratio) of power amplifier 21. Similarly, the chart shows the relationship between the output-side impedance of power amplifier 22 (impedance viewed from the output terminals of power amplifier 22) and the efficiency and ACLR of power amplifier 22. The efficiency distribution, represented by solid lines, shows the distribution of the efficiency of power amplifiers 21 and 22 relative to their output-side impedances. In the efficiency distribution, the closer to the center, the higher the efficiency; the maximum efficiency point 52 represents the output-side impedance of power amplifiers 21 and 22 when the efficiency is at its maximum. The ACLR distribution, represented by dashed lines, shows the distribution of the ACLR of power amplifiers 21 and 22 relative to their output-side impedances. In the ACLR distribution, the closer to the center, the smaller the ACLR. The minimum ACLR point 51 represents the output impedance of power amplifiers 21 and 22 when the ACLR is at its minimum. Here, the maximum efficiency point 52 and the minimum ACLR point 51 have different impedance values. Specifically, the impedance at the minimum ACLR point 51 is lower than the impedance at the maximum efficiency point 52.

[0094] In the separate transmission of the main signal in band A and the separate transmission of the main signal in band B, the output power of the main signal is, for example, about 26dBm. In the uplink 2×2 MIMO in band A, the output power of the MIMO signal is, for example, about 23dBm.

[0095] From this perspective, in the separate transmission of the main signal in band A, in order to prioritize suppressing signal distortion of the high output signal and thus minimize ACLR, it is desirable to match the output impedance of power amplifier 21 with a relatively low impedance. On the other hand, in the uplink 2×2 MIMO of band A, prioritizing the efficiency of the low output signal, it is desirable to match the output impedance of power amplifier 21 with a relatively high impedance.

[0096] Furthermore, in the separate transmission of the main signal in band B, in order to prioritize suppressing signal distortion of the high output signal and thus minimize ACLR, it is desirable to match the output impedance of power amplifier 22 with a relatively low impedance. On the other hand, in the uplink 2×2 MIMO in band A, prioritizing the efficiency of the low output signal, it is desirable to match the output impedance of power amplifier 22 with a relatively high impedance.

[0097] In other words, in the high-frequency circuit 1A and communication device 4A involved in this variation, it is desirable that when transmitting the main signal of frequency band A in frequency band A and B separately, the matching circuit 41 becomes the first impedance, and when the uplink of frequency band A is 2×2 MIMO, the matching circuit 41 becomes the second impedance, which is higher than the first impedance.

[0098] In addition, it is desirable that when transmitting the main signal of band B in band A and band B separately, the matching circuit 42 becomes the third impedance, and when the uplink of band A is 2×2 MIMO, the matching circuit 42 becomes the fourth impedance, which is higher than the third impedance.

[0099] Alternatively, either of the matching circuits 41 and 42 may be omitted.

[0100] [1.7 Effects of the high-frequency circuit and communication device involved in Implementation Method 1]

[0101] As described above, the high-frequency circuit 1 of this embodiment is capable of simultaneously transmitting signals in frequency band A and frequency band B, as well as uplink MIMO in frequency band A. It includes: a power amplifier 21 capable of amplifying signals in frequency band A; a power amplifier 22 capable of amplifying signals in both frequency band A and frequency band B; a filter 11, the passband of which includes the uplink operating frequency band of frequency band A; a filter 12, the passband of which includes the uplink operating frequency band of frequency band B; and a filter 13, different from filter 11, the passband of which includes the uplink operating frequency band of frequency band A. The link operates at a frequency band; and a switch 32 having terminals 32a, 32b, 32c, 32d and 32e, capable of simultaneously connecting terminals 32a and 32c and terminals 32b and 32d, and simultaneously connecting terminals 32a and 32c and terminals 32b and 32e, wherein terminal 32a is connected to the output terminal of power amplifier 21, terminal 32b is connected to the output terminal of power amplifier 22, terminal 32c is connected to filter 11, terminal 32d is connected to filter 12, and terminal 32e is connected to filter 13.

[0102] Accordingly, instead of configuring a dedicated power amplifier for the MIMO signal in band A, power amplifier 22 serves as both a power amplifier for amplifying the MIMO signal in band A and a power amplifier for amplifying the main signal in band B. This reduces the number of power amplifiers, thus enabling miniaturization of the high-frequency circuit 1. Therefore, a compact high-frequency circuit 1 capable of transmitting both MIMO and non-MIMO high-frequency signals can be provided.

[0103] Alternatively, in the high-frequency circuit 1 of this embodiment, when performing uplink MIMO in frequency band A, terminals 32a and 32c are connected, and terminals 32b and 32e are connected; when simultaneously transmitting signals in frequency band A and frequency band B, terminals 32a and 32c are connected, and terminals 32a and 32d are connected.

[0104] Accordingly, by switching action of switch 32, uplink CA of signal in frequency band A and signal in frequency band B and uplink MIMO of signal in frequency band A can be realized, thus simplifying high-frequency circuit 1.

[0105] Alternatively, in the high-frequency circuit 1 of this embodiment, terminals 32a and 32c may be connected when terminals 32b and 32e are connected.

[0106] Therefore, when filter 13 is used, filter 11 is always used. Thus, filter 13 can be used as a filter dedicated to 2×2 MIMO.

[0107] Alternatively, for example, the high-frequency circuit 1 involved in this embodiment may also include a switch 33, which has terminals 33a, 33b, 33c, 33d and 33e, and can simultaneously perform the connection between terminals 33a and 33c and the connection between terminals 33b and 33d, and can simultaneously perform the connection between terminals 33a and 33c and the connection between terminals 33b and 33e. Terminal 33a is connected to the input terminal of power amplifier 21, terminal 33b is connected to the input terminal of power amplifier 22, terminal 33c is input with a signal of frequency band A, terminal 33d is input with a signal of frequency band B, and terminal 33e is input with a signal of frequency band A.

[0108] Alternatively, in the high-frequency circuit 1 of this embodiment, when performing uplink MIMO in frequency band A, terminals 33a and 33c are connected, and terminals 33b and 33e are connected; when simultaneously transmitting signals in frequency band A and frequency band B, terminals 33a and 33c are connected, and terminals 33b and 33d are connected.

[0109] Accordingly, by switching the switch 33, the signal from RFIC 3 for uplink MIMO in band A and the signals from uplink CA in bands A and B can be distributed and input to power amplifiers 21 and 22, thus simplifying the high-frequency circuit 1.

[0110] For example, the high-frequency circuit 1A involved in this modification may also include a matching circuit 41, which is connected between the output terminal of the power amplifier 21 and the switch 32. The impedance of the matching circuit 41 is variable. When transmitting the main signal of frequency band A in frequency band A and B separately, the matching circuit 42 becomes the first impedance. When performing uplink MIMO in frequency band A, the matching circuit 42 becomes the second impedance, which is higher than the first impedance.

[0111] Therefore, when transmitting the main signal of band A alone, signal distortion of high output signals can be preferentially suppressed to reduce ACLR. Furthermore, when implementing uplink 2×2 MIMO in band A, the efficiency of low output signals can be improved.

[0112] For example, the high-frequency circuit 1A involved in this modification may also include a matching circuit 42, which is connected between the output terminal of the power amplifier 22 and the switch 32. The impedance of the matching circuit 42 is variable. When transmitting the main signal of frequency band B in frequency band A and B separately, the matching circuit 42 becomes the third impedance. When performing uplink MIMO in frequency band A, the matching circuit 42 becomes the fourth impedance, which is higher than the third impedance.

[0113] Therefore, when transmitting the main signal of frequency band B alone, signal distortion of high output signals can be preferentially suppressed to reduce ACLR. Furthermore, when implementing uplink 2×2 MIMO in frequency band A, the efficiency of low output signals can be improved.

[0114] Alternatively, for example, the high-frequency circuit 1 involved in this embodiment may also include a switch 31, which has terminals 31a, 31b, 31c, 31d and 31e, and can simultaneously perform the connection between terminals 31a and 31c and the connection between terminals 31b and 31d, and can simultaneously perform the connection between terminals 31a and 31c and the connection between terminals 31b and 31e. Terminal 31a is connected to antenna 2a, terminal 31b is connected to antenna 2b, terminal 31c is connected to filter 11, terminal 31d is connected to filter 12 and terminal 31e is connected to filter 13.

[0115] Alternatively, in the high-frequency circuit 1 of this embodiment, when performing uplink MIMO in frequency band A, terminals 31a and 31c are connected, and terminals 31b and 31e are connected; when simultaneously transmitting signals in frequency band A and frequency band B, terminals 31a and 31c are connected, and terminals 31b and 31d are connected.

[0116] Accordingly, by switching the switch 31, the signal from RFIC 3 for uplink MIMO in band A and the signals from uplink CA in bands A and B can be allocated and sent to antennas 2a and 2b, thus simplifying the high-frequency circuit 1.

[0117] Alternatively, in the high-frequency circuit 1 of this embodiment, frequency band A may belong to the high-frequency band group (2.4GHz-2.8GHz), and frequency band B may belong to the mid-frequency band group (1.5GHz-2.4GHz).

[0118] Alternatively, in the high-frequency circuit 1 of this embodiment, frequency band A may be Band 41 (2496MHz-2690MHz) and frequency band B may be Band 40 (2300MHz-2400MHz).

[0119] Alternatively, for example, in the high-frequency circuit 1 of this embodiment, the power amplifiers 21 and 22 and the switch 32 may be disposed on the same substrate.

[0120] Accordingly, the signal wiring connecting power amplifiers 21 and 22 to switch 32 can be shortened, thus reducing transmission losses of the high-power transmitted signals output from power amplifiers 21 and 22. Therefore, the power consumption of high-frequency circuit 1 can be reduced.

[0121] Alternatively, for example, in the high-frequency circuit 1 of this embodiment, power amplifiers 21 and 22, switches 32 and 33, and filters 11 to 13 may be disposed on the same substrate.

[0122] Accordingly, the transmission path from power amplifiers 21 and 22 to filters 11-13 can be shortened, thus further reducing the transmission loss of the high-power transmission signal output from power amplifiers 21 and 22. In addition, the high-frequency circuit 1 can be miniaturized.

[0123] In addition, the communication device 4 according to this embodiment includes: an RFIC 3 that processes high-frequency signals; and a high-frequency circuit 1 that transmits high-frequency signals between the RFIC 3 and antennas 2a and 2b.

[0124] Therefore, the effects of the high-frequency circuit 1 described above can be achieved in the communication device 4.

[0125] (Implementation Method 2)

[0126] The high-frequency circuit 1 involved in Embodiment 1 is a circuit capable of performing 2×2 MIMO. In contrast, the high-frequency circuit 1B involved in this embodiment is a circuit capable of performing 4×4 MIMO in addition to performing 2×2 MIMO.

[0127] [Circuit structure of high-frequency circuit 1B and communication device 4B]

[0128] The circuit structure of the high-frequency circuit 1B and the communication device 4B involved in this embodiment will be explained with reference to 7. Figure 7 This is a circuit structure diagram of the high-frequency circuit 1B and the communication device 4B involved in Embodiment 2.

[0129] [2.1 Circuit structure of communication device 4B]

[0130] First, the circuit structure of communication device 4B will be explained. For example... Figure 7 As shown, the communication device 4B according to this embodiment includes a high-frequency circuit 1B, antennas 2a, 2b, 2c and 2d, and an RFIC 3A.

[0131] High-frequency circuit 1B transmits high-frequency signals between antennas 2a-2d and RFIC 3A. The detailed circuit structure of high-frequency circuit 1B will be described later.

[0132] Antennas 2a and 2b are connected to switch 34 of high-frequency circuit 1B to transmit high-frequency signals output from high-frequency circuit 1B. In addition, after receiving high-frequency signals from the outside, the high-frequency signals are output to high-frequency circuit 1B.

[0133] RFIC 3A is an example of a signal processing circuit that processes high-frequency signals and has the same function as RFIC 3 in Embodiment 1.

[0134] RFIC 3A has terminals 30a, 30b, 30c, and 30d. Terminal 30a, facing high-frequency circuit 1B, outputs the main signal of frequency band A or B, or the MIMO signal of frequency band A. Terminal 30b, facing high-frequency circuit 1B, outputs the main signal of frequency band A or B, or the MIMO signal of frequency band A. Terminal 30c, facing high-frequency circuit 1B, outputs the MIMO signal of frequency band A. Terminal 30d, facing high-frequency circuit 1B, outputs the MIMO signal of frequency band A.

[0135] Furthermore, in the communication device 4B according to this embodiment, antennas 2a to 2d are not essential structural elements.

[0136] [2.2 Circuit Structure of High-Frequency Circuit 1B]

[0137] Next, the circuit structure of high-frequency circuit 1B will be explained. For example... Figure 7 As shown, the high-frequency circuit 1B includes filters 11, 12, 13, 14, 15 and 16, power amplifiers 21, 22, 23 and 24, and switches 34, 35 and 36.

[0138] The high-frequency circuit 1B according to this embodiment differs from the high-frequency circuit 1 according to Embodiment 1 in that it includes power amplifiers 23 and 24 and filters 14 to 16, and the structure of switches 34 to 36 is also different. Hereinafter, regarding the high-frequency circuit 1B according to this embodiment, descriptions of its identical structures to those of the high-frequency circuit 1 according to Embodiment 1 will be omitted, and the description will focus on its different structures.

[0139] Filter 11 is an example of a first filter, and the passband of filter 11 includes at least a portion of frequency band A (first frequency band). Filter 11 is connected between switches 34 and 35.

[0140] Filter 12 is an example of a second filter, and the passband of filter 12 includes at least a portion of frequency band B (second frequency band). Filter 12 is connected between switches 34 and 35.

[0141] Filter 13 is an example of a third filter, and its passband includes at least a portion of frequency band A. Filter 13 is connected between switches 34 and 35.

[0142] Filter 14 is an example of the fourth filter, and its passband includes at least a portion of frequency band A. Filter 14 is connected between switches 34 and 35.

[0143] Filter 15 is an example of the fifth filter, and the passband of filter 15 includes at least a portion of frequency band B. Filter 15 is connected between switches 34 and 35.

[0144] Filter 16 is an example of the sixth filter, and its passband includes at least a portion of frequency band A. Filter 16 is connected between switches 34 and 35.

[0145] Power amplifier 21 is an example of the first power amplifier, capable of amplifying the transmitted signal of frequency band A input from RFIC 3A via switch 36. Power amplifier 21 is connected between switches 35 and 36.

[0146] Power amplifier 22 is an example of a second power amplifier, capable of amplifying the transmitted signals of frequency bands A and B input from RFIC 3A via switch 36. Power amplifier 22 is connected between switches 35 and 36.

[0147] Power amplifier 23 is an example of a third power amplifier, capable of amplifying the transmitted signal of frequency band A input from RFIC 3A via switch 36. Power amplifier 23 is connected between switches 35 and 36.

[0148] Power amplifier 24 is an example of the fourth power amplifier, capable of amplifying the transmitted signals of frequency bands A and B input from RFIC 3A via switch 36. Power amplifier 24 is connected between switches 35 and 36.

[0149] Frequency band A, for example, belongs to the high-frequency band group (2.4 GHz - 2.8 GHz), and frequency band B, for example, belongs to the mid-frequency band group (1.5 GHz - 2.4 GHz). In particular, frequency band A is, for example, Band 41 (2496 MHz - 2690 MHz), and frequency band B is, for example, Band 40 (2300 MHz - 2400 MHz).

[0150] Switch 35 is an example of the first switch, and has terminals 35a (terminal 1), 35b (terminal 12), 35c (terminal 11), 35d (terminal 2), 35e (terminal 3), 35f (terminal 14), 35g (terminal 13), 35h (terminal 4), 35i (terminal 15), and 35j (terminal 5). Terminal 35a is connected to the output terminal of power amplifier 21, terminal 35d is connected to the output terminal of power amplifier 22, terminal 35c is connected to the output terminal of power amplifier 23, and terminal 35b is connected to the output terminal of power amplifier 24. Terminal 35e is connected to the input terminal of filter 11, terminal 35h is connected to the input terminal of filter 12, terminal 35j is connected to the input terminal of filter 13, terminal 35g is connected to the input terminal of filter 14, terminal 35f is connected to the input terminal of filter 15, and terminal 35i is connected to the input terminal of filter 16.

[0151] Switch 35 has a structure capable of simultaneously connecting terminals 35a and 35e, and terminals 35d and 35h; it can also simultaneously connect terminals 35a and 35e, terminals 35d and 35j, terminals 35c and 35g, and terminals 35b and 35i. Switch 35 is, for example, a 4P6T (4Pole 6Throw) type switch circuit.

[0152] Switch 36 is an example of the second switch, and has terminals 36a (terminal 6), 36b, 36c, 36d (terminal 7), 36e (terminal 8), 36f (terminal 9), 36g, and 36h (terminal 10). Terminal 36a is connected to the input terminal of power amplifier 21, terminal 36d is connected to the input terminal of power amplifier 22, terminal 36c is connected to the input terminal of power amplifier 23, and terminal 36b is connected to the input terminal of power amplifier 24. Terminal 36e is connected to terminal 30a, and terminal 36e receives the main signal of frequency band A or B, or the MIMO signal of frequency band A. Terminal 36f is connected to terminal 30b, and terminal 36f receives the main signal of frequency band A or B, or the MIMO signal of frequency band A. Terminal 36g is connected to terminal 30c, and terminal 36g receives the MIMO signal of frequency band A. Terminal 36h is connected to terminal 30d, and terminal 36h receives the MIMO signal of frequency band A.

[0153] Switch 36 has a structure capable of simultaneously connecting terminals 36a and 36e, and terminals 36d and 36f; it can also simultaneously connect terminals 36a and 36e, terminals 36b and 36g, terminals 36c and 36f, and terminals 36d and 36h. Switch 36 is, for example, a 4P4T (4Pole 4Throw) type switch circuit.

[0154] Switch 34 is an example of the third switch, and has terminals 34a (first antenna connection terminal), 34b (second antenna connection terminal), 34c (first antenna connection terminal), 34d (second antenna connection terminal), 34e (16th terminal), 34f, 34g, 34h (17th terminal), 34i, and 34j (18th terminal). Terminal 34a is connected to antenna 2a, terminal 34b is connected to antenna 2b, terminal 34c is connected to antenna 2c, and terminal 34d is connected to antenna 2d. Terminal 34e is connected to the output terminal of filter 11, terminal 34h is connected to the output terminal of filter 12, terminal 34j is connected to the output terminal of filter 13, terminal 34g is connected to the output terminal of filter 14, terminal 34f is connected to the output terminal of filter 15, and terminal 34i is connected to the output terminal of filter 16.

[0155] The switch 34 has a structure capable of simultaneously connecting terminals 34a and 34e, and terminals 34b and 34h; it can also simultaneously connect terminals 34a and 34e, terminals 34b and 34g, terminals 34c and 34i, and terminals 34d and 34j. The switch 34 is, for example, a 4P6T type switch circuit.

[0156] According to the above structure, the high-frequency circuit 1B and the communication device 4B can perform simultaneous transmission of signals in frequency band A and frequency band B, as well as uplink MIMO in frequency band A.

[0157] In conventional high-frequency circuits, in order to simultaneously transmit signals from frequency band A and frequency band B, as well as perform uplink 4×4 MIMO in frequency band A, more than four power amplifiers are required to amplify the transmitted signal from frequency band A and more than one power amplifier to amplify the transmitted signal from frequency band B.

[0158] In contrast, in the high-frequency circuit 1B according to Embodiment 2, power amplifiers 22 and 24 serve as power amplifiers for amplifying MIMO signals in frequency band A and power amplifiers for amplifying main signals in frequency band B, respectively. This reduces the number of power amplifiers in the high-frequency circuit 1B, thus enabling miniaturization of the high-frequency circuit 1B.

[0159] [2.3 Circuit connection status of high-frequency circuit 1B]

[0160] Next, the circuit connection state of the high-frequency circuit 1B corresponding to the signal transmission mode will be explained. The signal transmission modes that the high-frequency circuit 1B involved in this embodiment can perform are: (1) separate transmission of the main signal of band A; (2) separate transmission of the main signal of band B; (3) simultaneous transmission of the 4G signal and the 5G signal of band A (ENDC); (4) simultaneous transmission of the 4G signal and the 5G signal of band B (ENDC); (5) simultaneous transmission of the main signal of band A and the main signal of band B (dual uplink CA); (6) simultaneous transmission of dual uplink CA of bands A and B and uplink 2×2 MIMO of band A; and (7) MIMO transmission of band A (uplink 4×4 MIMO).

[0161] Figure 8 This is a circuit state diagram of the dual uplink ENDC of the high-frequency circuit 1A and the communication device 4B involved in Embodiment 2. Additionally, Figure 9 This is a circuit state diagram of the dual uplink CA of the high-frequency circuit 1B and the communication device 4B according to Embodiment 2. Additionally, Figure 10 This is a circuit state diagram of the dual uplink CA and uplink 2×2 MIMO of the high-frequency circuit 1B and communication device 4B involved in Embodiment 2. Additionally, Figure 11 This is a circuit state diagram of the uplink 4×4 MIMO of the high-frequency circuit 1B and the communication device 4B involved in Embodiment 2.

[0162] First, in the case of transmitting the main signal of frequency band A alone in (1), Figure 7In this configuration, terminals 36a and 36e are connected, terminals 35a and 35e are connected, and terminals 34a and 34e are connected. At this time, the transmitted signal for frequency band A is transmitted through the following transmission path: RFIC 3A, switch 36, power amplifier 21, switch 35, filter 11, switch 34, and antenna 2a.

[0163] Next, in the case of transmitting the main signal of frequency band B separately in (2), Figure 7 In this configuration, terminals 36b and 36e are connected, terminals 35b and 35f are connected, and terminals 34a and 34f are connected. At this time, the transmitted signal for frequency band B is transmitted through the following transmission path: RFIC 3A, switch 36, power amplifier 24, switch 35, filter 15, switch 34, and antenna 2a.

[0164] Next, in the case of simultaneously transmitting the 4G signal of band A and the 5G signal of band A (ENDC) in (3), as follows: Figure 8 As shown, terminals 36a and 36e are connected, terminals 35a and 35e are connected, and terminals 34a and 34e are connected. Simultaneously, terminals 36c and 36f are connected, terminals 35c and 35g are connected, and terminals 34b and 34g are connected. At this time, the 4G signal of band A is transmitted in the transmission path (first transmission path) consisting of RFIC 3A, switch 36, power amplifier 21, switch 35, filter 11, switch 34, and antenna 2a. Simultaneously, the 5G signal of band A is transmitted in the transmission path (second transmission path) consisting of RFIC 3A, switch 36, power amplifier 23, switch 35, filter 14, switch 34, and antenna 2b.

[0165] Alternatively, the 4G signal of band A can be transmitted in the second transmission path, while the 5G signal of band A can be transmitted in the first transmission path.

[0166] Next, in the case of simultaneously transmitting the 4G signal of band B and the 5G signal of band A (ENDC) in (4), Figure 1In this configuration, terminals 36b and 36e are connected, terminals 35b and 35f are connected, and terminals 34a and 34f are connected. Simultaneously, terminals 36d and 36f are connected, terminals 35d and 35h are connected, and terminals 34b and 34h are connected. At this time, the 4G signal of band B is transmitted through the transmission path (third transmission path) consisting of RFIC 3A, switch 36, power amplifier 24, switch 35, filter 15, switch 34, and antenna 2a. Simultaneously, the 5G signal of band B is transmitted through the transmission path (fourth transmission path) consisting of RFIC 3A, switch 36, power amplifier 22, switch 35, filter 12, switch 34, and antenna 2b.

[0167] Alternatively, the 4G signal of band B can be transmitted in the fourth transmission path, and the 5G signal of band B can also be transmitted in the fourth transmission path.

[0168] Next, in the case of simultaneous transmission of the main signal of frequency band A and the main signal of frequency band B (dual uplink CA), such as Figure 9 As shown, terminals 36a and 36e are connected, terminals 35a and 35e are connected, and terminals 34a and 34e are connected. Simultaneously, terminals 36d and 36f are connected, terminals 35d and 35h are connected, and terminals 34b and 34h are connected. At this time, the main signal of frequency band A is transmitted through the following transmission path: RFIC 3A, switch 36, power amplifier 21, switch 35, filter 11, switch 34, and antenna 2a. Simultaneously, the main signal of frequency band B is transmitted through the following transmission path: RFIC 3A, switch 36, power amplifier 22, switch 35, filter 12, switch 34, and antenna 2b.

[0169] Next, in the case of simultaneous transmission of dual uplink CA in frequency bands A and B and uplink 2×2 MIMO in frequency band A, such as Figure 10As shown, terminals 36a and 36e are connected, terminals 35a and 35e are connected, and terminals 34a and 34e are connected. Simultaneously, terminals 36b and 36g are connected, terminals 35b and 35i are connected, and terminals 34c and 34i are connected. At the same time, terminals 36d and 36f are connected, terminals 35d and 35h are connected, and terminals 34b and 34h are connected. At this time, the main signal of frequency band A is transmitted through the transmission path of RFIC 3A, switch 36, power amplifier 21, switch 35, filter 11, switch 34, and antenna 2a. Additionally, simultaneously, the main signal of frequency band B is transmitted through the transmission path of RFIC 3A, switch 36, power amplifier 22, switch 35, filter 12, switch 34, and antenna 2b. In addition, the MIMO signal of band A is transmitted in the following transmission paths: RFIC 3A, switch 36, power amplifier 24, switch 35, filter 16, switch 34, and antenna 2c.

[0170] Next, in the case of MIMO transmission in band A (7) (uplink 4×4 MIMO), as follows Figure 11 As shown, terminals 36a and 36e are connected, terminals 35a and 35e are connected, and terminals 34a and 34e are connected. Simultaneously, terminals 36b and 36g are connected, terminals 35b and 35i are connected, and terminals 34c and 34i are connected. Simultaneously, terminals 36c and 36f are connected, terminals 35c and 35g are connected, and terminals 34b and 34g are connected. Simultaneously, terminals 36d and 36h are connected, terminals 35d and 35j are connected, and terminals 34d and 34j are connected. At this time, the MIMO signal of frequency band A is transmitted through the following transmission path: RFIC 3A, switch 36, power amplifier 21, switch 35, filter 11, switch 34, and antenna 2a. Additionally, the MIMO signal in band A is simultaneously transmitted through a transmission path consisting of RFIC 3A, switch 36, power amplifier 24, switch 35, filter 16, switch 34, and antenna 2c. Furthermore, the MIMO signal in band A is simultaneously transmitted through a transmission path consisting of RFIC 3A, switch 36, power amplifier 23, switch 35, filter 14, switch 34, and antenna 2b. Additionally, the MIMO signal in band A is simultaneously transmitted through a transmission path consisting of RFIC 3A, switch 36, power amplifier 22, switch 35, filter 13, switch 34, and antenna 2d.

[0171] Furthermore, when terminals 35d and 35j are connected, terminals 35a and 35e are always connected. Similarly, when terminals 35b and 35j are connected, terminals 35a and 35e are always connected. Filters 13 and 16 are MIMO-specific filters; therefore, when filter 13 is used, filter 11 is always used as a MIMO filter, and when filter 16 is used, filter 11 is always used as a MIMO filter.

[0172] [2.4 Module Structure of High-Frequency Circuit 1B]

[0173] In the high-frequency circuit 1B of this embodiment, power amplifiers 21 to 24 and switch 35 are disposed on the same first substrate.

[0174] Therefore, the signal wiring connecting power amplifiers 21-24 to switch 35 can be shortened, thus reducing transmission losses of the high-power transmitted signals output from power amplifiers 21-24. Consequently, the power consumption of high-frequency circuit 1B can be reduced.

[0175] Furthermore, switches 34 and 36 can also be disposed together with switch 35 on the first substrate. Additionally, switches 34, 35, and 36 can be included in the same semiconductor IC. This allows for miniaturization of the high-frequency circuit 1B.

[0176] Furthermore, in the high-frequency circuit 1B of this embodiment, in addition to arranging the power amplifiers 21-24 and switches 34-36 on the first substrate, filters 11-16 may also be arranged on the first substrate.

[0177] Accordingly, the transmission path from power amplifiers 21-24 to switch 34 can be shortened, thus further reducing the transmission loss of the high-power transmission signal output from power amplifiers 21-24. Additionally, the high-frequency circuit 1B can be miniaturized.

[0178] [2.5 Impedance Matching of High-Frequency Circuit 1B]

[0179] Furthermore, in the high-frequency circuit 1B according to this embodiment, a third matching circuit with variable impedance may be connected between the output terminal of the power amplifier 21 and the switch 35. The third matching circuit includes at least one of an inductor and a capacitor. Alternatively, a fourth matching circuit with variable impedance may be connected between the output terminal of the power amplifier 24 and the switch 35. The fourth matching circuit includes at least one of an inductor and a capacitor.

[0180] Here, in the case of (1) transmitting the main signal of band A in both band A and band B separately, the third matching circuit becomes the fifth impedance. Furthermore, in the case of (5) simultaneous transmission of the signal in band A and the signal in band B (dual uplink CA), or (6) performing uplink 2×2 MIMO in band A, the third matching circuit becomes the sixth impedance, which is higher than the fifth impedance. Furthermore, in the case of (7) performing uplink 4×4 MIMO in band A, the third matching circuit becomes the seventh impedance, which is higher than the sixth impedance.

[0181] In the solo transmission of the main signal in band A, the output power of each main signal is, for example, approximately 26 dBm. Furthermore, in the dual uplink CA of the signal in band A and the signal in band B, and in the uplink 2×2 MIMO of band A, the output power of each MIMO signal is, for example, approximately 23 dBm. Additionally, in the uplink 4×4 MIMO of band A, the output power of each MIMO signal is, for example, approximately 20 dBm.

[0182] From this perspective, in the solo transmission of the main signal in band A, priority is given to suppressing signal distortion of high output signals, and it is desirable to match the output impedance of power amplifier 21 with a relatively low impedance (the 5th impedance). On the other hand, in the uplink 4×4 MIMO of band A, the efficiency of low output signals is emphasized, and it is desirable to match the output impedance of power amplifier 21 with a relatively high impedance (the 7th impedance). Furthermore, in the dual uplink CA of signals from band A and band B, and the uplink 2×2 MIMO of band A, it is desirable to match the output impedance of power amplifier 21 with the impedance between the 5th and 7th impedances (the 6th impedance).

[0183] Furthermore, in (2) when the main signal of band B in band A and band B is transmitted separately, the fourth matching circuit becomes the eighth impedance. Additionally, in (5) when the signal of band A and the signal of band B are transmitted simultaneously (dual uplink CA), or in (6) when uplink 2×2 MIMO of band A is performed, the fourth matching circuit becomes the ninth impedance, which is higher than the eighth impedance. Furthermore, in (7) when uplink 4×4 MIMO of band A is performed, the fourth matching circuit becomes the tenth impedance, which is higher than the ninth impedance.

[0184] In the solo transmission of the main signal in band B, the output power of each main signal is, for example, approximately 26 dBm. Furthermore, in the dual uplink CA of signals from band A and band B, and in the uplink 2×2 MIMO of band A, the output power of each MIMO signal is, for example, approximately 23 dBm. Additionally, in the uplink 4×4 MIMO of band A, the output power of each MIMO signal is, for example, approximately 20 dBm.

[0185] From this perspective, in the solo transmission of the main signal in band B, priority is given to suppressing signal distortion of high output signals, and it is desirable to match the output impedance of power amplifier 24 with a relatively low impedance (the 8th impedance). On the other hand, in the uplink 4×4 MIMO of band A, the efficiency of low output signals is emphasized, and it is desirable to match the output impedance of power amplifier 24 with a relatively high impedance (the 10th impedance). Furthermore, in the dual uplink CA of signals from band A and band B, and the uplink 2×2 MIMO of band A, it is desirable to match the output impedance of power amplifier 24 with the impedance between the 8th and 10th impedances (the 9th impedance).

[0186] [2.6 Effects of the high-frequency circuit and communication device involved in Implementation Method 1B]

[0187] As described above, the high-frequency circuit 1B according to this embodiment is capable of simultaneously transmitting signals in frequency band A and frequency band B, as well as uplink MIMO in frequency band A. It includes: a power amplifier 21 capable of amplifying signals in frequency band A; a power amplifier 22 capable of amplifying signals in both frequency band A and frequency band B; a filter 11, the passband of which includes at least a portion of frequency band A; a filter 12, the passband of which includes at least a portion of frequency band B; and a filter 13, different from filter 11, the passband of which includes at least a portion of frequency band A. A smaller portion; and a switch 35 having terminals 35a, 35d, 35e, 35h and 35j, capable of simultaneously performing the connection between terminals 35a and 35e and the connection between terminals 35d and 35h, capable of simultaneously performing the connection between terminals 35a and 35e and the connection between terminals 35d and 35j, terminal 35a connected to the output terminal of power amplifier 21, terminal 35d connected to the output terminal of power amplifier 22, terminal 35e connected to filter 11, terminal 35h connected to filter 12, and terminal 35j connected to filter 13.

[0188] Accordingly, power amplifier 22 serves as both a power amplifier for amplifying MIMO signals in frequency band A and a power amplifier for amplifying main signals in frequency band B. This reduces the number of power amplifiers, thus enabling miniaturization of the high-frequency circuit 1B. Therefore, a compact high-frequency circuit 1B capable of transmitting both MIMO and non-MIMO high-frequency signals can be provided.

[0189] Alternatively, for example, the high-frequency circuit 1B according to this embodiment may also include: a power amplifier 23 capable of amplifying signals in frequency band A; a power amplifier 24 capable of amplifying signals in frequency band A and frequency band B; a filter 14, the passband of which includes at least a portion of frequency band A; a filter 15, the passband of which includes at least a portion of frequency band B; and a filter 16, the passband of which includes at least a portion of frequency band A, wherein the switch 35 further includes terminals 35c, 35b, 35g, 35f, and 35i. It can simultaneously perform the connection between terminals 35a and 35e and the connection between terminals 35d and 35h, and can simultaneously perform the connection between terminals 35a and 35e, terminals 35d and 35j, terminals 35c and 35g, and terminals 35b and 35i. Terminal 35c is connected to the output terminal of power amplifier 23, terminal 35b is connected to the output terminal of power amplifier 24, terminal 35g is connected to filter 14, terminal 35f is connected to filter 15, and terminal 35i is connected to filter 16.

[0190] Alternatively, in the high-frequency circuit 1B of this embodiment, when performing uplink 4×4 MIMO in frequency band A, terminals 35a and 35e are connected, terminals 35d and 35j are connected, terminals 35c and 35g are connected, and terminals 35b and 35i are connected. When performing simultaneous transmission of signals in frequency band A and frequency band B, terminals 35a and 35e are connected, and terminals 35d and 35h are connected.

[0191] Accordingly, by switching action of switch 35, uplink 4×4 MIMO of frequency band A and uplink CA of signals of frequency band A and signals of frequency band B can be realized, thus simplifying high-frequency circuit 1B.

[0192] Alternatively, in the high-frequency circuit 1B of this embodiment, terminals 35a and 35e may be connected, and terminals 35c and 35g may be connected, when transmitting signals for band A for 4G-LTE and band A for 5G-NR simultaneously.

[0193] Therefore, by switching the switch 35, the ENDC of frequency band A can be achieved, thus simplifying the high-frequency circuit 1B.

[0194] Alternatively, in the high-frequency circuit 1B of this embodiment, terminals 35a and 35e may be connected, and terminals 35d and 35h may be connected, and terminals 35b and 35i may be connected, when the signal of frequency band A and the signal of frequency band B are transmitted simultaneously and the uplink 2×2 MIMO of frequency band A is executed simultaneously.

[0195] Accordingly, by switching action of switch 35, the signal of frequency band A and the signal of frequency band B can be transmitted simultaneously, and the uplink 2×2 MIMO of frequency band A can be executed simultaneously, thus simplifying the high-frequency circuit 1B.

[0196] For example, the high-frequency circuit 1B involved in this modification may also include a third matching circuit, which is connected between the output terminal of the power amplifier 21 and the switch 35. The impedance of the third matching circuit is variable. When transmitting the main signal of frequency band A in frequency band A and B separately, the third matching circuit becomes the fifth impedance. When performing uplink CA of the signal of frequency band A and the signal of frequency band B, or when performing uplink 2×2 MIMO of frequency band A, the third matching circuit becomes the sixth impedance, which is higher than the fifth impedance. When performing uplink 4×4 MIMO of frequency band A, the third matching circuit becomes the seventh impedance, which is higher than the sixth impedance.

[0197] Therefore, when transmitting the main signal of band A alone, signal distortion of high output signals can be suppressed preferentially to reduce ACLR. Furthermore, when implementing uplink 4×4 MIMO in band A, the efficiency of low output signals can be improved.

[0198] For example, the high-frequency circuit 1B involved in this modification may also include a fourth matching circuit, which is connected between the output terminal of the power amplifier 24 and the switch 35. The impedance of the fourth matching circuit is variable. When transmitting the main signal of frequency band B in frequency band A and B separately, the fourth matching circuit becomes the eighth impedance. When performing uplink CA of the signal of frequency band A and the signal of frequency band B, or performing uplink 2×2 MIMO of frequency band A, the fourth matching circuit becomes the ninth impedance, which is higher than the eighth impedance. When performing uplink 4×4 MIMO of frequency band A, the fourth matching circuit becomes the tenth impedance, which is higher than the ninth impedance.

[0199] Therefore, when transmitting the main signal of frequency band B alone, signal distortion of high output signals can be preferentially suppressed to reduce ACLR. Furthermore, when implementing uplink 4×4 MIMO in frequency band A, the efficiency of low output signals can be improved.

[0200] Alternatively, for example, the high-frequency circuit 1B involved in this embodiment may also include a switch 34, which has terminals 34a, 34b, 34e, 34h and 34j, and can simultaneously perform the connection between terminals 34a and 34e and the connection between terminals 34b and 34h, and can simultaneously perform the connection between terminals 34a and 34e and the connection between terminals 34b and 34j. Terminal 34a is connected to antenna 2a, terminal 34b is connected to antenna 2b, terminal 34e is connected to filter 11, terminal 34h is connected to filter 12, and terminal 34j is connected to filter 13.

[0201] Alternatively, in the high-frequency circuit 1B of this embodiment, when performing uplink MIMO in frequency band A, terminals 34a and 34e are connected, terminals 34d and 34j are connected, terminals 34c and 34i are connected, and terminals 34b and 34g are connected. When performing simultaneous transmission of signals in frequency band A and frequency band B, terminals 34a and 34e are connected, and terminals 34b and 34h are connected.

[0202] Accordingly, by switching the switch 34, the signal from RFIC 3A for uplink 4×4 MIMO in band A and the signals from uplink CA in bands A and B can be allocated and sent to antennas 2a to 2d, thus simplifying the high-frequency circuit 1B.

[0203] Alternatively, in the high-frequency circuit 1B of this embodiment, frequency band A may belong to the high-frequency band group (2.4GHz-2.8GHz), and frequency band B may belong to the mid-frequency band group (1.5GHz-2.4GHz).

[0204] Alternatively, in the high-frequency circuit 1B of this embodiment, frequency band A may be Band 41 (2496MHz-2690MHz) and frequency band B may be Band 40 (2300MHz-2400MHz).

[0205] Alternatively, for example, in the high-frequency circuit 1B according to this embodiment, the power amplifiers 21 to 24 and the switch 35 may be disposed on the same substrate.

[0206] Therefore, the signal wiring connecting power amplifiers 21-24 to switch 35 can be shortened, thus reducing transmission losses of the high-power transmitted signals output from power amplifiers 21-24. Consequently, the power consumption of high-frequency circuit 1B can be reduced.

[0207] Alternatively, for example, in the high-frequency circuit 1B according to this embodiment, the power amplifiers 21-24, switches 35 and 36, and filters 11-16 may be disposed on the same substrate.

[0208] Accordingly, the transmission path from power amplifiers 21-24 to filters 11-16 can be shortened, thus further reducing the transmission loss of the high-power transmission signal output from power amplifiers 21-24. Furthermore, the high-frequency circuit 1B can be miniaturized.

[0209] In addition, the communication device 4B according to this embodiment includes: an RFIC 3A that processes high-frequency signals; and a high-frequency circuit 1B that transmits high-frequency signals between the RFIC 3A and antennas 2a to 2d.

[0210] Accordingly, the effects of the aforementioned high-frequency circuit 1B can be achieved in the communication device 4B.

[0211] (Modified Example)

[0212] The above description of the high-frequency circuit and communication device according to the present invention is based on embodiments and modifications. However, the high-frequency circuit and communication device according to the present invention are not limited to the above embodiments and modifications. Other embodiments implemented by combining any structural elements in the above embodiments and modifications, modifications obtained by implementing the above embodiments and modifications in various ways 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.

[0213] For example, in the circuit structure of the high-frequency circuit and communication device described in the above embodiments and modifications, other circuit elements and wiring may be inserted between the paths connecting the circuit elements and signal paths disclosed in the drawings. For example, in the high-frequency circuit 1, a matching circuit may be inserted between the power amplifiers 21 and 22 and the switch 33 and / or between the filters 11 to 13 and the switch 31.

[0214] Furthermore, while the above embodiments and variations illustrate a dual uplink structure that simultaneously transmits signals in frequency band A and frequency band B, the high-frequency circuit and communication device structure of the present invention can also be applied to structures that simultaneously use uplinks and / or downlinks (e.g., 3 uplinks and 3 downlinks) in three or more different frequency bands. In other words, the present invention also includes high-frequency front-end modules or communication devices that include the structure of the high-frequency front-end modules or communication devices described in the above embodiments and variations, which perform the simultaneous use of uplinks and / or downlinks in three or more different frequency bands.

[0215] Furthermore, in the above embodiments and variations, uplink 2×2 MIMO and uplink 4×4 MIMO structures for performing frequency band A are illustrated, but the structure of the high-frequency circuit and communication device involved in the present invention can also be applied to structures such as 8×8 MIMO and 16×16 MIMO.

[0216] Industrial availability

[0217] This invention, as a front-end module supporting multiple frequency bands / modes using MIMO and carrier aggregation, can be widely applied to communication devices such as portable phones.

[0218] Explanation of reference numerals in the attached figures

[0219] 1. 1A, 1B, 301: High-frequency circuits; 2a, 2b, 2c, 2d: Antennas; 3. 3A: RF signal processing circuit (RFIC); 4. 4A, 4B, 304: Communication devices; 11, 12, 13, 14, 15, 16: Filters; 21, 22, 23, 24, 322, 323: Power amplifiers; 31, 32, 33, 34, 35, 36, 332, 333: Switches; 30a, 30b, 30c, 30d, 31a, 31b, 31c, 31d, 31e, 32 a, 32b, 32c, 32d, 32e, 33a, 33b, 33c, 33d, 33e, 34a, 34b, 34c, 34d, 34e, 34f, 34g, 34h, 34i, 34j, 35a, 35b, 35c, 35d, 35e, 35f, 35g, 35h, 35i, 35j, 36a, 36b, 36c, 36d, 36e, 36f, 36g, 36h: Terminals; 41, 42: Matching circuit; 51: Minimum ACLR point; 52: Maximum efficiency point.

Claims

1. A high-frequency circuit capable of simultaneously transmitting signals in a first frequency band and signals in a second frequency band, and performing uplink multiple-input multiple-output (MIMO) in the first frequency band, said high-frequency circuit comprising: The first power amplifier is capable of amplifying the signal in the first frequency band; The second power amplifier is capable of amplifying the signals of the first frequency band and the signals of the second frequency band; A first filter, wherein the passband of the first filter includes at least a portion of the first frequency band; A second filter, wherein the passband of the second filter includes at least a portion of the second frequency band; The third filter, unlike the first filter, has a passband that includes at least a portion of the first frequency band; and A first switch has a first terminal, a second terminal, a third terminal, a fourth terminal, and a fifth terminal, and is capable of simultaneously connecting the first terminal to the third terminal and connecting the second terminal to the fourth terminal, and simultaneously connecting the first terminal to the third terminal and connecting the second terminal to the fifth terminal. in, The first terminal is connected to the output terminal of the first power amplifier. The second terminal is connected to the output terminal of the second power amplifier. The third terminal is connected to the first filter. The fourth terminal is connected to the second filter. The fifth terminal is connected to the third filter. When performing uplink MIMO in the first frequency band, the first switch is switched such that the first terminal is connected to the third terminal and the second terminal is connected to the fifth terminal. When transmitting signals from the first frequency band and the second frequency band simultaneously, the first switch is switched such that the first terminal is connected to the third terminal and the second terminal is connected to the fourth terminal.

2. The high-frequency circuit according to claim 1, wherein, When the second terminal and the fifth terminal are connected, the first terminal and the third terminal are connected.

3. The high-frequency circuit according to claim 1 or 2, wherein, It also includes a second switch having a 6th terminal, a 7th terminal, an 8th terminal, a 9th terminal, and a 10th terminal, capable of simultaneously connecting the 6th terminal to the 8th terminal and the 7th terminal to the 9th terminal, and simultaneously connecting the 6th terminal to the 8th terminal and the 7th terminal to the 10th terminal. The sixth terminal is connected to the input terminal of the first power amplifier. The 7th terminal is connected to the input terminal of the 2nd power amplifier. The 8th terminal is input with the signal of the 1st frequency band. The 9th terminal is input with the signal of the 2nd frequency band. The 10th terminal is input with the signal of the 1st frequency band.

4. The high-frequency circuit according to claim 3, wherein, When performing uplink MIMO in the first frequency band, the sixth terminal is connected to the eighth terminal, and the seventh terminal is connected to the tenth terminal. When transmitting signals from the first frequency band and the second frequency band simultaneously, the sixth terminal is connected to the eighth terminal, and the seventh terminal is connected to the ninth terminal.

5. The high-frequency circuit according to claim 1 or 2, wherein, It also includes a first matching circuit, which is connected between the output terminal of the first power amplifier and the first switch. The impedance of the first matching circuit is variable. When transmitting the main signal of the first frequency band and the second frequency band separately, the first matching circuit becomes the first impedance. When performing uplink MIMO in the first frequency band, the first matching circuit becomes a second impedance that is higher than the first impedance.

6. The high-frequency circuit according to claim 1 or 2, wherein, It also includes a second matching circuit, which is connected between the output terminal of the second power amplifier and the first switch. The impedance of the second matching circuit is variable. When transmitting the main signal of the second frequency band in both the first and second frequency bands separately, the second matching circuit becomes the third impedance. When performing uplink MIMO in the first frequency band, the second matching circuit becomes a fourth impedance that is higher than the third impedance.

7. The high-frequency circuit according to claim 1, wherein, It also has: Unlike the first power amplifier, the third power amplifier is capable of amplifying signals in the first frequency band; Unlike the second power amplifier, the fourth power amplifier is capable of amplifying both the first and second frequency band signals; The fourth filter, unlike the first filter, has a passband that includes at least a portion of the first frequency band; Unlike the second filter, the fifth filter's passband includes at least a portion of the second frequency band; and Unlike the first filter and the third filter, the sixth filter's passband includes at least a portion of the first frequency band. The first switch also has an 11th terminal, a 12th terminal, a 13th terminal, a 14th terminal, and a 15th terminal, and is capable of simultaneously performing connections between the 1st terminal and the 3rd terminal, the 2nd terminal and the 5th terminal, the 11th terminal and the 13th terminal, and the 12th terminal and the 15th terminal. The 11th terminal is connected to the output terminal of the 3rd power amplifier. The 12th terminal is connected to the output terminal of the 4th power amplifier. The 13th terminal is connected to the 4th filter. The 14th terminal is connected to the 5th filter. The 15th terminal is connected to the 6th filter.

8. The high-frequency circuit according to claim 7, wherein, When performing uplink 4×4 MIMO in the first frequency band, the first terminal is connected to the third terminal, the second terminal is connected to the fifth terminal, the eleventh terminal is connected to the thirteenth terminal, and the twelfth terminal is connected to the fifteenth terminal. When transmitting signals from the first frequency band and the second frequency band simultaneously, the first terminal is connected to the third terminal, and the second terminal is connected to the fourth terminal.

9. The high-frequency circuit according to claim 8, wherein, When simultaneously transmitting signals of the first frequency band used for 4G Long Term Evolution (4G-LTE) and signals of the first frequency band used for 5G New Radio (5G-NR), the first terminal and the third terminal are connected, and the eleventh terminal and the thirteenth terminal are connected.

10. The high-frequency circuit according to claim 8 or 9, wherein, When the signal of the first frequency band and the signal of the second frequency band are transmitted simultaneously, and the uplink 2×2 MIMO of the first frequency band is executed simultaneously, the first terminal is connected to the third terminal, the second terminal is connected to the fourth terminal, and the 12th terminal is connected to the 15th terminal.

11. The high-frequency circuit according to any one of claims 7 to 9, wherein, It also includes a third matching circuit, which is connected between the output terminal of the third power amplifier and the first switch. The impedance of the third matching circuit is variable. When transmitting the main signal of the first frequency band and the second frequency band separately, the third matching circuit becomes the fifth impedance. When performing uplink 2×2 MIMO in the first frequency band, or when transmitting signals from the first frequency band and the second frequency band simultaneously, the third matching circuit becomes a sixth impedance that is higher than the fifth impedance. When performing uplink 4×4 MIMO in the first frequency band, the third matching circuit becomes the seventh impedance, which is higher than the sixth impedance.

12. The high-frequency circuit according to any one of claims 7 to 9, wherein, It also includes a fourth matching circuit, which is connected between the output terminal of the fourth power amplifier and the first switch. The impedance of the fourth matching circuit is variable. When transmitting the main signal of the second frequency band in both the first and second frequency bands separately, the fourth matching circuit becomes the eighth impedance. When performing uplink 2×2 MIMO in the first frequency band, or when transmitting signals from the first frequency band and the second frequency band simultaneously, the fourth matching circuit becomes a ninth impedance that is higher than the eighth impedance. When performing uplink 4×4 MIMO in the first frequency band, the fourth matching circuit becomes the tenth impedance, which is higher than the ninth impedance.

13. The high-frequency circuit according to claim 1 or 2, wherein, It also includes a third switch, which has a first antenna connection terminal, a second antenna connection terminal, a 16th terminal, a 17th terminal, and an 18th terminal, and is capable of simultaneously performing connections between the first antenna connection terminal and the 16th terminal, and between the second antenna connection terminal and the 18th terminal. The first antenna connection terminal is connected to the first antenna. The second antenna connection terminal is connected to the second antenna. The 16th terminal is connected to the 1st filter. The 17th terminal is connected to the 2nd filter. The 18th terminal is connected to the 3rd filter.

14. The high-frequency circuit according to claim 13, wherein, When performing uplink MIMO in the first frequency band, the first antenna connection terminal is connected to the 16th terminal, and the second antenna connection terminal is connected to the 18th terminal. When transmitting signals from the first frequency band and the second frequency band simultaneously, the first antenna connection terminal is connected to the 16th terminal, and the second antenna connection terminal is connected to the 17th terminal.

15. The high-frequency circuit according to claim 1 or 2, wherein, The first frequency band belongs to the high-frequency band group, namely 2.4GHz-2.8GHz. The second frequency band belongs to the mid-frequency band group, namely 1.5GHz-2.4GHz.

16. The high-frequency circuit according to claim 15, wherein, The first frequency band is Band 41, i.e., 2496MHz-2690MHz. The second frequency band is Band40, which is 2300MHz-2400MHz.

17. The high-frequency circuit according to claim 1, wherein, The first power amplifier, the second power amplifier, and the first switch are configured on the same substrate.

18. The high-frequency circuit according to claim 3, wherein, The first power amplifier, the second power amplifier, the first switch, the second switch, the first filter, the second filter, and the third filter are disposed on the same substrate.

19. A communication device comprising: Signal processing circuitry that processes high-frequency signals; and The high-frequency circuit according to any one of claims 1 to 18 transmits the high-frequency signal between the signal processing circuit and the antenna.

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