High-frequency circuit

Abstract

A high-frequency circuit (1) is provided with: a filter (31) having a passband including a frequency band (A) for TDD; a filter (32) having a passband including a frequency band B for TDD, the frequency band B being capable of simultaneous transmission and reception with the frequency band A; a filter (33) having a passband including a frequency band A; a filter (34) having a passband including a frequency band B; filters (35, 36), each of which has a passband including a frequency band A and a frequency band B, the filters (35, 36) being connected to the input / output terminal (101); a switching circuit (51) including a terminal (511) connected to the power amplifier (11) and terminals (512, 513) respectively connected to the filters (31, 32); and a switching circuit (52) including terminals (521-526) connected to the filters (31-36), respectively, and a terminal (527) connected to the input / output terminal (102) without passing through the filters (35 and 36).

Description

Technical Field

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

[0002] Within the 3GPP (3rd Generation Partnership Project), research is underway on combining two Time Division Duplex (TDD) frequency bands to simultaneously transmit and receive using Simultaneous Rx / Tx.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: U.S. Patent Application Publication No. 2015 / 0133067 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] However, in conventional high-frequency circuits disclosed in Patent Document 1, there is a concern about the degradation of the received signal quality in Simultaneous Rx / Tx.

[0008] Therefore, the present invention provides a high-frequency circuit that can improve the quality of received signals in a Simultaneous Rx / Tx.

[0009] Solution for solving the problem

[0010] One aspect of the present invention relates to a high-frequency circuit comprising: a first power amplifier; a first low-noise amplifier and a second low-noise amplifier; a first filter connected to the first power amplifier in a switchable manner, having a passband including a first frequency band for time-division duplexing; a second filter connected to the first power amplifier in a switchable manner, having a passband including a second frequency band for time-division duplexing, wherein the second frequency band and the first frequency band can be transmitted and received simultaneously; a third filter connected to the first low-noise amplifier, having a passband including the first frequency band; a fourth filter connected to the second low-noise amplifier, having a passband including the second frequency band; and a fifth filter, one end of which is connected to the first filter and the third filter in a switchable manner, and the other end of which is connected to a first input / output terminal. The filter has a passband that includes a first frequency band; a sixth filter, one end of which is switchably connected to the second filter and the fourth filter respectively, and the other end of which is connected to the first input / output terminal, the sixth filter having a passband that includes a second frequency band; a first switching circuit, which includes a first terminal connected to the first power amplifier, a second terminal connected to the first filter, and a third terminal connected to the second filter; and a second switching circuit, which includes a fourth terminal connected to the first filter, a fifth terminal connected to the second filter, a sixth terminal connected to the third filter, a seventh terminal connected to the fourth filter, an eighth terminal connected to the fifth filter, a ninth terminal connected to the sixth filter, and a tenth terminal connected to the second input / output terminal without passing through the fifth filter and the sixth filter.

[0011] The effects of the invention

[0012] The high-frequency circuit according to one aspect of the present invention can improve the quality of the received signal in a Simultaneous Rx / Tx. Attached Figure Description

[0013] Figure 1 This is a circuit diagram of the communication device involved in Embodiment 1.

[0014] Figure 2 This is a diagram illustrating the first connection method of the communication device according to Embodiment 1.

[0015] Figure 3 This is a diagram illustrating a second connection method of the communication device according to Embodiment 1.

[0016] Figure 4 This is a diagram illustrating a third connection method of the communication device according to Embodiment 1.

[0017] Figure 5 This is a diagram illustrating a fourth connection method of the communication device according to Embodiment 1.

[0018] Figure 6 This is a diagram illustrating the fifth connection method of the communication device according to Embodiment 1.

[0019] Figure 7 This is a diagram illustrating the sixth connection method of the communication device according to Embodiment 1.

[0020] Figure 8 This is a diagram illustrating the seventh connection method of the communication device according to Embodiment 1.

[0021] Figure 9 This is a circuit diagram of the communication device involved in Embodiment 2.

[0022] Figure 10 This is a diagram illustrating the first connection method of the communication device according to Embodiment 2.

[0023] Figure 11 This is a diagram illustrating a second connection method of the communication device according to Embodiment 2.

[0024] Figure 12 This is a diagram illustrating a third connection method of the communication device according to Embodiment 2.

[0025] Figure 13 This is a diagram illustrating the fourth connection method of the communication device according to Embodiment 2.

[0026] Figure 14 This is a diagram illustrating the fifth connection method of the communication device according to Embodiment 2.

[0027] Figure 15 This is a diagram illustrating the sixth connection method of the communication device according to Embodiment 2.

[0028] Figure 16 This is a diagram illustrating the seventh connection method of the communication device according to Embodiment 2.

[0029] Figure 17 This is a circuit diagram of the communication device involved in Embodiment 3.

[0030] Figure 18 This is a diagram illustrating the first connection method of the communication device according to Embodiment 3.

[0031] Figure 19 This is a diagram illustrating a second connection method of the communication device according to Embodiment 3.

[0032] Figure 20 This is a diagram illustrating a third connection method of the communication device according to Embodiment 3.

[0033] Figure 21This is a circuit diagram of the communication device involved in Embodiment 4.

[0034] Figure 22 This is a diagram showing a first mode of the communication device according to Embodiment 4.

[0035] Figure 23 This is a diagram showing a second mode of the communication device according to Embodiment 4.

[0036] Figure 24 This is a diagram showing the third mode of the communication device according to Embodiment 4.

[0037] Figure 25 This is a diagram illustrating the fourth mode of the communication device according to Embodiment 4.

[0038] Figure 26 This is a circuit diagram of the communication device involved in a variation of Embodiment 4, Example 1.

[0039] Figure 27 This is a diagram showing a first mode of the communication device involved in a variation of Embodiment 4, Example 1.

[0040] Figure 28 This is a diagram showing a second mode of the communication device involved in a variation of Embodiment 4, Example 1.

[0041] Figure 29 This is a diagram showing a third mode of the communication device involved in a variation of Embodiment 4, Example 1.

[0042] Figure 30 This is a diagram showing the fourth mode of the communication device involved in Variation 1 of Embodiment 4.

[0043] Figure 31 This is a circuit diagram of the communication device involved in Variation 2 of Embodiment 4.

[0044] Figure 32 This is a circuit diagram of the communication device involved in Variation 3 of Embodiment 4.

[0045] Figure 33 This is a circuit diagram of the communication device according to Embodiment 5.

[0046] Figure 34 This is a diagram showing a first mode of the communication device according to Embodiment 5.

[0047] Figure 35 This is a diagram illustrating a second mode of the communication device according to Embodiment 5.

[0048] Figure 36 This is a diagram illustrating the third mode of the communication device according to Embodiment 5.

[0049] Figure 37 This is a diagram illustrating the fourth mode of the communication device according to Embodiment 5.

[0050] Figure 38 This is a circuit diagram of the communication device according to Embodiment 6.

[0051] Figure 39 This is a circuit diagram of the communication device according to Embodiment 7.

[0052] Figure 40 This is a circuit diagram of the communication device involved in a variation of Embodiment 7. Detailed Implementation

[0053] Hereinafter, embodiments of the present invention will 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, constituent elements, arrangements of constituent elements, and connection methods shown in the following embodiments are examples and are not intended to limit the present invention.

[0054] 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.

[0055] In circuit structure, "connection" includes not only direct connections via connection terminals and / or wiring conductors, but also electrical connections via other circuit elements. "C connected between A and B" means one end of C is connected to A, and the other end of C is connected to B; it means C is connected in series in the path connecting A and B. "A and B are connected in a switchable manner" means that the connection and non-connection between A and B can be switched; it means A is connected to B via a switch. Furthermore, "A and B connected" includes "A and B are connected in a switchable manner."

[0056] In circuit structure, a "terminal" refers to the point where a conductor within an element terminates. Furthermore, when the impedance between conductors within an element is sufficiently low, a terminal can be interpreted not only as a single point, but also as any point on the conductor between elements or the entire conductor.

[0057] The "passband" of a filter is the portion of the spectrum transmitted by the filter, defined as the frequency band where the output power does not decrease by more than 3dB compared to the maximum output power. The "attenuation band" of a filter is defined as the frequency band where the output power decreases by more than 5dB compared to the maximum output power.

[0058] "Transmit band" refers to the frequency band used for transmitting in a communication device, while "receive band" refers to the frequency band used for receiving in a communication device. For example, in the Frequency Division Duplex (FDD) band, different frequency bands are used as the transmit and receive bands (e.g., uplink and downlink bands). Conversely, in the TDD band, for example, the transmit and receive bands use the same frequency band.

[0059] (Implementation Method 1)

[0060] Implementation method 1 will be described. The communication device 5 involved in this implementation functions as a UE in a cellular network, typically a portable phone, smartphone, tablet computer, wearable device, etc. Furthermore, the communication device 5 can also be an IoT (Internet of Things) sensor device, medical / healthcare equipment, a vehicle, an unmanned aerial vehicle (UAV), or an automated guided vehicle (AGV). Additionally, the communication device 5 can also function as a BS in a cellular network.

[0061] 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 according to this embodiment. In the following figures, the dashed lines in the switching circuit represent the paths between terminals that can be connected.

[0062] also, Figure 1 The circuit structure provided is exemplary; the communication device 5 and the high-frequency circuit 1 can be installed using any of a variety of circuit mounting methods and techniques. Therefore, the following description of the communication device 5 and the high-frequency circuit 1 should not be interpreted restrictively.

[0063] [1.1 Circuit structure of communication device 5]

[0064] First, refer to Figure 1 The circuit structure of the communication device 5 according to this embodiment will be explained. The communication device 5 is installed in the UE and includes a high-frequency circuit 1, an antenna 2, an RFIC (Radio Frequency Integrated Circuit) 3, a BBIC (Baseband Integrated Circuit) 4, and a switching circuit 53.

[0065] 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.

[0066] Antenna 2 is connected to switching circuit 53. Antenna 2 can receive high-frequency signals from outside the communication device 5 and provide the high-frequency signals to high-frequency circuit 1 via switching circuit 53. Furthermore, antenna 2 can transmit the high-frequency signals provided from high-frequency circuit 1 to the outside of the communication device 5 via switching circuit 53. Alternatively, antenna 2 may not be included in the communication device 5. Additionally, the communication device 5 may have one or more antennas besides antenna 2.

[0067] RFIC 3 is an example of a signal processing circuit that processes high-frequency signals. Specifically, RFIC 3 can process the high-frequency received signal input via the receiving path of high-frequency circuit 1 through down-conversion or the like, and output the received signal generated by the signal processing to BBIC 4. Furthermore, RFIC 3 can process the transmitted signal input from BBIC 4 through up-conversion or the like, and output the high-frequency transmitted signal generated by the signal processing to high-frequency circuit 1. In addition, RFIC 3 may also include a control unit for controlling switches and power amplifiers in high-frequency circuit 1. Furthermore, part or all of the control unit may be located outside of RFIC 3, for example, it may be included in BBIC 4 or high-frequency circuit 1.

[0068] BBIC 4 is a baseband signal processing circuit that performs signal processing using a frequency band lower than the frequency of the high-frequency signal transmitted by high-frequency circuit 1. Signals processed by BBIC 4 include, for example, image signals used for image display and / or sound signals used for communication via a speaker. Furthermore, BBIC 4 may not be included in the communication device 5.

[0069] Switching circuit 53 is an example of a third switching circuit, connected between antenna 2 and high-frequency circuit 1. Specifically, switching circuit 53 includes terminals 531 to 533. Terminal 531 is an example of an eleventh terminal, connected to antenna 2. Terminal 532 is an example of a twelfth terminal, connected to input / output terminal 101 of high-frequency circuit 1. Terminal 533 is an example of a thirteenth terminal, connected to input / output terminal 102 of high-frequency circuit 1. In such a connection structure, switching circuit 53 can, for example, connect terminals 531, 532, and 533 exclusively based on control signals from RFIC 3. Switching circuit 53 is, for example, constructed as an SPDT (Single-Pole Double-Throw) type switching circuit. Furthermore, switching circuit 53 may also be included in high-frequency circuit 1.

[0070] [1.2 Circuit Structure of High-Frequency Circuit 1]

[0071] Next, refer to Figure 1The circuit structure of the high-frequency circuit 1 according to this embodiment will be described below. The high-frequency circuit 1 includes a power amplifier 11, low-noise amplifiers 21 and 22, filters 31 to 36, switching circuits 51 and 52, input and output terminals 101 and 102, input terminal 111, and output terminals 121 and 122.

[0072] Input / output terminals 101 and 102 are examples of the first and second input / output terminals, respectively, and are external connection terminals of the high-frequency circuit 1. Input / output terminal 101 is connected externally to terminal 532 of the switching circuit 53 and internally to filters 35 and 36 of the high-frequency circuit 1. Input / output terminal 102 is connected externally to terminal 533 of the switching circuit 53 and internally to terminal 527 of the switching circuit 52 of the high-frequency circuit 1.

[0073] Furthermore, input / output terminals 101 and / or 102 may not be external connection terminals of the high-frequency circuit 1. For example, when the switching circuit 53 is included in the high-frequency circuit 1, input / output terminal 101 may be a path connecting filters 35 and 36 to terminal 532 of the switching circuit 53 or a node on that path, and input / output terminal 102 may be a path connecting terminal 527 of the switching circuit 52 to terminal 533 of the switching circuit 53 or a node on that path.

[0074] Input terminal 111 is an external connection terminal of high-frequency circuit 1, and is a high-frequency input terminal. Input terminal 111 is connected to RFIC 3 externally and to power amplifier 11 internally within high-frequency circuit 1. Input terminal 111 can receive transmitted signals from frequency bands A and B from RFIC 3.

[0075] Output terminals 121 and 122 are external connection terminals of the high-frequency circuit 1, and are high-frequency output terminals. Output terminal 121 is connected externally to RFIC 3 and internally to low-noise amplifier 21 of the high-frequency circuit 1. Output terminal 122 is connected externally to RFIC 3 and internally to low-noise amplifier 22 of the high-frequency circuit 1. Output terminal 121 can provide the RFIC 3 with a received signal of frequency band A, and output terminal 122 can provide the RFIC 3 with a received signal of frequency band B.

[0076] Power amplifier 11 is an example of a first power amplifier. The input terminal of power amplifier 11 is connected to input terminal 111. The output terminal of power amplifier 11 is connected to filters 31 and 32 via switching circuit 51. Power amplifier 11 can amplify the transmitted signals of frequency bands A and B provided from RFIC 3 via input terminal 111 using power supplied from a power source (not shown).

[0077] The power amplifier 11 can be constructed from a heterojunction bipolar transistor (HBT) and can be manufactured using semiconductor materials. For example, silicon germanium (SiGe) or gallium arsenide (GaAs) can be used as semiconductor materials. Furthermore, the amplifying transistor of the power amplifier 11 is not limited to an HBT. For example, the 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 semiconductor materials.

[0078] Low-noise amplifier 21 is an example of a first low-noise amplifier. The input terminal of low-noise amplifier 21 is connected to filter 33. The output terminal of low-noise amplifier 21 is connected to output terminal 121. Low-noise amplifier 21 can amplify the received signal in frequency band A that has passed through filter 33 using power supplied from a power source (not shown).

[0079] Low-noise amplifier 22 is an example of a second low-noise amplifier. The input of low-noise amplifier 22 is connected to filter 34. The output of low-noise amplifier 22 is connected to output terminal 122. Low-noise amplifier 22 can amplify the received signal in frequency band B that has passed through filter 34 using power supplied from a power source (not shown).

[0080] Low-noise amplifiers 21 and 22 can be constructed using field-effect transistors (FETs) and can be manufactured using semiconductor materials. Examples of semiconductor materials include single-crystal silicon, GaN, or SiC. Furthermore, the amplifying transistors in low-noise amplifiers 21 and 22 are not limited to FETs. For example, some or all of low-noise amplifiers 21 and 22 can also be constructed using bipolar transistors.

[0081] Filter 31 is an example of the first filter and is a bandpass filter having a passband that includes frequency band A. One end of filter 31 is connected to terminal 512 of switching circuit 51, and is connected to power amplifier 11 in a switchable manner via switching circuit 51. On the other hand, the other end of filter 31 is connected to terminal 521 of switching circuit 52, and is connected to input and output terminals 101 and 102 in a switchable manner via switching circuit 52. In this embodiment, filter 31 is used for transmitting signals in frequency band A (A-Tx).

[0082] Filter 32 is an example of a second filter, and is a bandpass filter having a passband that includes frequency band B. One end of filter 32 is connected to terminal 513 of switching circuit 51, and is connected to power amplifier 11 in a switchable manner via switching circuit 51. On the other hand, the other end of filter 32 is connected to terminal 522 of switching circuit 52, and is connected to input and output terminals 101 and 102 in a switchable manner via switching circuit 52. In this embodiment, filter 32 is used for transmitting signals in frequency band B (B-Tx).

[0083] Filter 33 is an example of a third filter, and is a bandpass filter having a passband that includes frequency band A. One end of filter 33 is connected to low-noise amplifier 21. On the other hand, the other end of filter 33 is connected to terminal 523 of switching circuit 52, and is connected to input and output terminals 101 and 102 in a switchable manner via switching circuit 52. In this embodiment, filter 33 is used for receiving signals in frequency band A (A-Rx).

[0084] Filter 34 is an example of a fourth filter, and is a bandpass filter having a passband that includes frequency band B. One end of filter 34 is connected to low-noise amplifier 22. On the other hand, the other end of filter 34 is connected to terminal 524 of switching circuit 52, and is connected to input and output terminals 101 and 102 in a switchable manner via switching circuit 52. In this embodiment, filter 34 is used for receiving signals in frequency band B (B-Rx).

[0085] Filter 35 is an example of a fifth filter, and is a bandpass filter having a passband that includes frequency band A. One end of filter 35 is connected to terminal 525 of switching circuit 52, and is connected to filters 31 and 33 in a switchable manner via switching circuit 52. On the other hand, the other end of filter 35 is connected to input / output terminal 101. In this embodiment, filter 35 is used for transmitting and receiving signals in frequency band A of Simultaneous Rx / Tx (A-Tx / Rx).

[0086] Filter 36 is an example of the sixth filter and is a bandpass filter having a passband that includes frequency band B. One end of filter 36 is connected to terminal 526 of switching circuit 52, and is connected to filters 32 and 34 in a switchable manner via switching circuit 52. On the other hand, the other end of filter 36 is connected to input / output terminal 101. In this embodiment, filter 36 is used for transmitting and receiving signals in frequency band B of Simultaneous Rx / Tx (B-Tx / Rx).

[0087] As such filters 31 to 36, surface acoustic wave (SAW) filters, bulk acoustic wave (BAW) filters, LC filters, or dielectric filters, or any combination thereof, may be used, and are not limited to them.

[0088] Switching circuit 51 is an example of a first switching circuit, connected between power amplifier 11 and filters 31 and 32. Specifically, switching circuit 51 includes terminals 511 to 513. Terminal 511 is an example of a first terminal, connected to power amplifier 11. Terminal 512 is an example of a second terminal, connected to filter 31. Terminal 513 is an example of a third terminal, connected to filter 32.

[0089] In such a connection structure, the switching circuit 51 can, for example, connect terminals 511, 512, and 513 in an exclusive manner based on control signals from RFIC 3. The switching circuit 51 is, for example, constructed from an SPDT-type switching circuit.

[0090] Switching circuit 52 is an example of a second switching circuit, connected between filters 31-34 and input / output terminals 101 and 102. Specifically, switching circuit 52 includes terminals 521-527. Terminal 521 is an example of a fourth terminal, connected to filter 31. Terminal 522 is an example of a fifth terminal, connected to filter 32. Terminal 523 is an example of a sixth terminal, connected to filter 33. Terminal 524 is an example of a seventh terminal, connected to filter 34. Terminal 525 is an example of an eighth terminal, connected to filter 35, and connected to input / output terminal 101 via filter 35. Terminal 526 is an example of a ninth terminal, connected to filter 36, and connected to input / output terminal 102 via filter 36. Terminal 527 is an example of a tenth terminal, connected to input / output terminal 102 without passing through filters 35 and 36.

[0091] In this connection structure, the switching circuit 52 can, for example, connect terminals 521-524 to terminals 525-527 based on control signals from RFIC 3. Specifically, terminal 521 is exclusively connected to terminals 525 and 527, terminal 522 is exclusively connected to terminals 526 and 527, terminal 523 is exclusively connected to terminals 525 and 527, and terminal 524 is exclusively connected to terminals 526 and 527. The switching circuit 52 is, for example, configured as a multi-connection type switching circuit.

[0092] [1.3 band]

[0093] Here, a specific example of the frequency band used in the communication device 5 according to this embodiment will be described.

[0094] Frequency bands A and B are examples of the first and second frequency bands, respectively, and are predefined by standardization organizations (such as 3GPP and IEEE) for communication systems built using Radio Access Technology (RAT). Examples of communication systems include 5G NR (5th Generation New Radio) systems, LTE (Long Term Evolution) systems, and WLAN (Wireless Local Area Network) systems.

[0095] Frequency bands A and B are both frequency bands used in TDD, and are combinations of frequency bands that can simultaneously transmit and receive. Combinations of frequency bands A and B can use either Band40 (2300MHz-2400MHz) for LTE or n40 (2300MHz-2400MHz) for 5G NR, or Band41 (2496MHz-2690MHz) for LTE or n41 (2496MHz-2690MHz) for 5G NR. Alternatively, instead of using Band40 for LTE or n40 for 5G NR, one can use Band39 (1880MHz-1920MHz) for LTE or n39 (1880MHz-1920MHz) for 5G NR. Furthermore, instead of using Band40 for LTE or n40 for 5G NR, Band34 for LTE or n34 for 5G NR can be used, or n97 for 5G NR can also be used. Additionally, the combination of frequency bands A and B is not limited to the above.

[0096] [1.4 Connection method within communication device 5]

[0097] Next, the various connection methods within the communication device 5 will be explained.

[0098] [1.4.1 First Connection Method]

[0099] First, refer to Figure 2 The first connection method will be explained. Figure 2 This diagram illustrates a first connection method of the communication device 5 according to this embodiment. In the following diagrams, dashed arrows indicate signal flow.

[0100] In the first connection method, it is possible to simultaneously transmit signals in frequency band A and receive signals in frequency band B. That is, the first connection method is for Simultaneous Rx / Tx connections. For example... Figure 2 As shown, in the first connection method, switch circuit 51 connects terminals 511 and 512, switch circuit 52 connects terminals 521 and 525, and connects terminals 524 and 526, and switch circuit 53 connects terminals 531 and 532. Thus, filters 31 and 35 are connected to the transmission path of frequency band A, and filters 34 and 36 are connected to the reception path of frequency band B.

[0101] As a result, the transmitted signal of band A is transmitted from RFIC 3 to antenna 2 via input terminal 111, power amplifier 11, switching circuit 51, filter 31, switching circuit 52, filter 35, input / output terminal 101, and switching circuit 53. The received signal of band B is transmitted from antenna 2 to RFIC 3 via switching circuit 53, input / output terminal 101, filter 36, switching circuit 52, filter 34, low-noise amplifier 22, and output terminal 122.

[0102] [1.4.2 Second Connection Method]

[0103] Next, refer to Figure 3 The second connection method will be explained. Figure 3 This diagram illustrates a second connection method of the communication device 5 according to this embodiment.

[0104] In the second connection method, it is possible to simultaneously receive signals from frequency band A and transmit signals from frequency band B. That is, the second connection method is for Simultaneous Rx / Tx connections. For example... Figure 3 As shown, in the second connection method, switch circuit 51 connects terminals 511 and 513, switch circuit 52 connects terminals 522 and 526, and connects terminals 523 and 525, and switch circuit 53 connects terminals 531 and 532. Thus, filters 32 and 36 are connected to the transmission path of frequency band B, and filters 33 and 35 are connected to the reception path of frequency band A.

[0105] As a result, the transmitted signal of band B is transmitted from RFIC 3 to antenna 2 via input terminal 111, power amplifier 11, switching circuit 51, filter 32, switching circuit 52, filter 36, input / output terminal 101, and switching circuit 53. The received signal of band A is transmitted from antenna 2 to RFIC 3 via switching circuit 53, input / output terminal 101, filter 35, switching circuit 52, filter 33, low-noise amplifier 21, and output terminal 121.

[0106] [1.4.3 Third Connection Method]

[0107] Next, refer to Figure 4 The third connection method will be explained. Figure 4 This diagram illustrates a third connection method of the communication device 5 according to this embodiment.

[0108] In the third connection method, it is possible to simultaneously receive signals from frequency band A and frequency band B. For example... Figure 4 As shown, in the third connection method, switch circuit 52 connects terminals 523 and 524 to terminal 527, and switch circuit 53 connects terminals 531 and 533. Thus, filter 33 is connected to the receiving path of frequency band A, and filter 34 is connected to the receiving path of frequency band B.

[0109] As a result, the received signal in band A is transmitted from antenna 2 to RFIC 3 via switching circuit 53, input / output terminal 102, switching circuit 52, filter 33, low-noise amplifier 21, and output terminal 121. The received signal in band B is transmitted from antenna 2 to RFIC 3 via switching circuit 53, input / output terminal 102, switching circuit 52, filter 34, low-noise amplifier 22, and output terminal 122.

[0110] [1.4.4 Fourth Connection Method]

[0111] Next, refer to Figure 5 The fourth connection method will be explained. Figure 5 This diagram illustrates the fourth connection method of the communication device 5 according to this embodiment.

[0112] In the fourth connection mode, signals in frequency band A can be transmitted independently. TDD for frequency band A is achieved by alternately switching between the fourth and fifth connection states. For example... Figure 5 As shown, in the fourth connection method, switch circuit 51 connects terminal 511 to terminal 512, switch circuit 52 connects terminal 521 to terminal 527, and switch circuit 53 connects terminal 531 to terminal 533. Thus, filter 31 is connected to the transmission path of frequency band A.

[0113] As a result, the transmit signal of band A is transmitted from RFIC 3 to antenna 2 via input terminal 111, power amplifier 11, switching circuit 51, filter 31, switching circuit 52, input / output terminal 102, and switching circuit 53.

[0114] [1.4.5 Fifth Connection Method]

[0115] Next, refer to Figure 6 The fifth connection method will be explained. Figure 6 This diagram illustrates the fifth connection method of the communication device 5 according to this embodiment.

[0116] In the fifth connection mode, signals in band A can be received independently. TDD in band A is achieved by alternately switching between the fourth and fifth connection states. For example... Figure 6 As shown, in the fifth connection method, switch circuit 52 connects terminal 523 to terminal 527, and switch circuit 53 connects terminal 531 to terminal 533. Thus, filter 33 is connected to the receiving path of frequency band A.

[0117] As a result, the received signal of band A is transmitted from antenna 2 to RFIC 3 via switching circuit 53, input / output terminal 102, switching circuit 52, filter 33, low noise amplifier 21 and output terminal 121.

[0118] [1.4.6 Sixth Connection Method]

[0119] Next, refer to Figure 7 The sixth connection method will be explained. Figure 7 This diagram illustrates the sixth connection method of the communication device 5 according to this embodiment.

[0120] In the sixth connection mode, signals in frequency band B can be transmitted independently. TDD for frequency band B is achieved by alternately switching between the sixth and seventh connection states. For example... Figure 7 As shown, in the sixth connection method, switch circuit 51 connects terminal 511 to terminal 513, switch circuit 52 connects terminal 522 to terminal 527, and switch circuit 53 connects terminal 531 to terminal 533. Thus, filter 32 is connected to the transmission path of frequency band B.

[0121] As a result, the transmit signal of band B is transmitted from RFIC 3 to antenna 2 via input terminal 111, power amplifier 11, switching circuit 51, filter 32, switching circuit 52, input / output terminal 102, and switching circuit 53.

[0122] [1.4.7 Seventh Connection Method]

[0123] Next, refer to Figure 8 The seventh connection method will be explained. Figure 8 This diagram illustrates the seventh connection method of the communication device 5 according to this embodiment.

[0124] In the seventh connection mode, signal reception in band B can be performed independently. TDD in band B is achieved by alternately switching between the sixth and seventh connection states. For example... Figure 8As shown, in the seventh connection method, switch circuit 52 connects terminal 524 to terminal 527, and switch circuit 53 connects terminal 531 to terminal 533. Thus, filter 34 is connected to the receiving path of frequency band B.

[0125] As a result, the received signal of band B is transmitted from antenna 2 to RFIC 3 via switching circuit 53, input / output terminal 102, switching circuit 52, filter 34, low noise amplifier 22 and output terminal 122.

[0126] [1.5 Summary]

[0127] As described above, the high-frequency circuit 1 according to this embodiment includes: a power amplifier 11; low-noise amplifiers 21 and 22; a filter 31, which is switchably connected to the power amplifier 11 and has a passband including frequency band A for TDD; a filter 32, which is switchably connected to the power amplifier 11 and has a passband including frequency band B for TDD, wherein frequency band B and frequency band A can be transmitted and received simultaneously; a filter 33, which is connected to the low-noise amplifier 21 and has a passband including frequency band A; a filter 34, which is connected to the low-noise amplifier 22 and has a passband including frequency band B; and a filter 35, one end of which is switchably connected to filters 31 and 33 respectively, and the other end of which is connected to the input / output terminal 101, wherein filter 35 has a passband including frequency band A. The passband of band A; filter 36, one end of which is connected to filters 32 and 34 in a switchable manner, and the other end of which is connected to input / output terminal 101, filter 36 having a passband including band B; switching circuit 51, which includes terminal 511 connected to power amplifier 11, terminal 512 connected to filter 31 and terminal 513 connected to filter 32; and switching circuit 52, which includes terminal 521 connected to filter 31, terminal 522 connected to filter 32, terminal 523 connected to filter 33, terminal 524 connected to filter 34, terminal 525 connected to filter 35, terminal 526 connected to filter 36, and terminal 527 connected to input / output terminal 102 without passing through filters 35 and 36.

[0128] Therefore, the switching circuit 52 can switch between paths connected to the input / output terminal 101 via filters 35 and 36, and paths connected to the input / output terminal 101 without using filters 35 and 36. Thus, in Simultaneous Rx / Tx, by connecting filters 31-34 to the input / output terminal 101 via filters 35 and 36, interference between the transmitted signal of one frequency band and the received signal of the other frequency band and can be suppressed, thereby improving the quality of the received signal of the other frequency band and frequency band. In particular, it is difficult to sufficiently attenuate the transmitted signal using only the receiving filters (filters 33 and 34) used in the TDD band; therefore, the improvement in isolation between the transmitted and received paths achieved by filters 35 and 36 is more significant. On the other hand, in addition to Simultaneous Rx / Tx, by connecting filters 31 to 34 to the input / output terminals 102 without passing through filters 35 and 36, signal loss caused by filters 35 and 36 can be avoided, and the increase in the required output power of the power amplifier 11 and the decrease in receiving sensitivity can be suppressed.

[0129] Additionally, for example, the high-frequency circuit 1 according to this embodiment may also include a switching circuit 53, which includes a terminal 531 connected to the antenna 2, a terminal 532 connected to the input / output terminal 101, and a terminal 533 connected to the input / output terminal 102.

[0130] Therefore, the connection of antenna 2 can be switched between input / output terminal 101 and input / output terminal 102, and Simultaneous Rx / Tx can be achieved through one antenna 2.

[0131] Alternatively, for example, in the high-frequency circuit 1 according to this embodiment, when transmitting in frequency band A and receiving in frequency band B simultaneously, the switching circuit 51 connects terminal 511 to terminal 512, the switching circuit 52 connects terminal 521 to terminal 525, and connects terminal 524 to terminal 526, and the switching circuit 53 connects terminal 531 to terminal 532.

[0132] Therefore, in the Simultaneous Rx / Tx based on transmission in band A and reception in band B, filter 31 is connected to input / output terminal 101 via filter 35, and filter 34 is connected to input / output terminal 101 via filter 36. Thus, the two filters 34 and 36 can suppress the intrusion of the transmitted signal from band A into the reception path of band B, improving the quality of the received signal in band B. For example, if the switching circuit 52 connects terminals 521 and 524 to terminal 527, so that filters 31 and 34 are connected to input / output terminal 102 without passing through filters 35 and 36, the transmitted signal from band A leaks from filter 34 to the low-noise amplifier 22, degrading the quality of the received signal in band B. Conversely, by connecting filters 31 and 34 to input / output terminal 101 via filters 35 and 36, the leakage of the transmitted signal from band A to the low-noise amplifier 22 is suppressed by the two filters 34 and 36, improving the quality of the received signal in band B.

[0133] Alternatively, for example, in the high-frequency circuit 1 according to this embodiment, when receiving frequency band A and transmitting frequency band B simultaneously, the switching circuit 51 connects terminal 511 to terminal 513, the switching circuit 52 connects terminal 522 to terminal 526, and connects terminal 523 to terminal 525, and the switching circuit 53 connects terminal 531 to terminal 532.

[0134] Therefore, in the Simultaneous Rx / Tx based on reception in band A and transmission in band B, filter 33 is connected to input / output terminal 101 via filter 35, and filter 32 is connected to input / output terminal 101 via filter 36. Thus, the intrusion of the transmission signal from band B into the reception path of band A can be suppressed by the two filters 33 and 35, improving the quality of the received signal in band A. For example, if the switching circuit 52 connects terminals 522 and 523 to terminal 527, so that filters 32 and 33 are connected to input / output terminal 102 without passing through filters 35 and 36, the transmission signal from band B leaks from filter 33 to the low-noise amplifier 21, degrading the quality of the received signal in band A. In contrast, by connecting filters 32 and 33 to input / output terminal 101 via filters 35 and 36, the leakage of the transmission signal from band B to the low-noise amplifier 21 is suppressed by the two filters 33 and 35, improving the quality of the received signal in band A.

[0135] Alternatively, for example, in the high-frequency circuit 1 according to this embodiment, when receiving frequency band A and frequency band B simultaneously, the switching circuit 52 connects terminals 523 and 524 to terminal 527, and the switching circuit 53 connects terminals 531 and 533.

[0136] Therefore, when receiving signals simultaneously in frequency bands A and B, filters 33 and 34 are connected to the input / output terminal 102 without passing through filters 35 and 36. This avoids signal loss caused by filters 35 and 36 and suppresses the decrease in receiving sensitivity when receiving signals simultaneously in frequency bands A and B.

[0137] Alternatively, for example, in the high-frequency circuit 1 of this embodiment, the combination of frequency bands A and B may be a combination of Band 40 for LTE or n40 for 5G NR and Band 41 for LTE or n41 for 5G NR, or a combination of Band 39 for LTE or n39 for 5G NR and Band 41 for LTE or n41 for 5G NR.

[0138] This enables improvements in the quality of received signals during Simultaneous Rx / Tx communication in LTE or 5G NR networks.

[0139] In addition, the communication device 5 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 the antenna 2.

[0140] Therefore, the same effect as the high-frequency circuit 1 can be achieved through the communication device 5.

[0141] (Implementation Method 2)

[0142] Next, Embodiment 2 will be described. The main difference between this embodiment and Embodiment 1 is that the high-frequency circuit 1 is configured to use filters 31 and 32 not only as transmitting filters but also as receiving filters. Hereinafter, this embodiment will be described with reference to the accompanying drawings, focusing on the differences from Embodiment 1.

[0143] [2.1 Circuit Structure of High-Frequency Circuit 1A]

[0144] Reference Figure 9 The circuit structure of the high-frequency circuit 1A involved in this embodiment will be explained. Figure 9 This is a circuit diagram of the communication device 5A involved in this embodiment.

[0145] also, Figure 9 The circuit structures provided are illustrative, and the communication device 5A and the high-frequency circuit 1A can be installed using any of a variety of circuit mounting methods and techniques. Therefore, the descriptions of the communication device 5A and the high-frequency circuit 1A provided below should not be interpreted restrictively.

[0146] The communication device 5A according to this embodiment is the same as the communication device 5 according to embodiment 1, except that it has a high-frequency circuit 1A instead of a high-frequency circuit 1, so its description is omitted.

[0147] The high-frequency circuit 1A involved in this embodiment includes a power amplifier 11, low-noise amplifiers 21 and 22, filters 31A to 36A, switching circuits 51A, 52, 54A and 55A, input and output terminals 101 and 102, input terminal 111, and output terminals 121 and 122.

[0148] Filter 31A is an example of the first filter and is a bandpass filter having a passband that includes frequency band A. One end of filter 31A is connected to terminal 512 of switching circuit 51A, and is connected in a switchable manner to power amplifier 11 via switching circuit 51A, and to low-noise amplifier 21 via switching circuits 51A and 54A, respectively. On the other hand, the other end of filter 31A is connected to terminal 521 of switching circuit 52, and is connected in a switchable manner to input and output terminals 101 and 102, respectively, via switching circuit 52. In this embodiment, filter 31A is used for transmission and reception (A-Tx / Rx) of frequency band A.

[0149] Filter 32A is an example of a second filter, and is a bandpass filter having a passband that includes frequency band B. One end of filter 32A is connected to terminal 513 of switching circuit 51A, and is connected in a switchable manner to power amplifier 11 via switching circuit 51A, and to low-noise amplifier 22 via switching circuits 51A and 55A, respectively. On the other hand, the other end of filter 32A is connected to terminal 522 of switching circuit 52, and is connected in a switchable manner to input and output terminals 101 and 102, respectively, via switching circuit 52. In this embodiment, filter 32A is used for transmission and reception of frequency band B (B-Tx / Rx).

[0150] Filter 33A is an example of a third filter, and is a bandpass filter having a passband that includes frequency band A. One end of filter 33A is connected to terminal 543 of switching circuit 54A, and is connected to low-noise amplifier 21 in a switchable manner via switching circuit 54A. On the other hand, the other end of filter 33A is connected to terminal 523 of switching circuit 52, and is connected to input and output terminals 101 and 102 in a switchable manner via switching circuit 52. In this embodiment, filter 33A is used for receiving frequency band A (A-Rx) in Simultaneous Rx / Tx. Furthermore, filter 33A is not limited to a bandpass filter. For example, filter 33A can also be a high-pass filter or a low-pass filter.

[0151] Filter 34A is an example of a fourth filter, and is a bandpass filter having a passband that includes frequency band B. One end of filter 34A is connected to terminal 553 of switching circuit 55A, and is connected to low-noise amplifier 22 via switching circuit 55A. On the other hand, the other end of filter 34A is connected to terminal 524 of switching circuit 52, and is connected to input and output terminals 101 and 102 in a switchable manner via switching circuit 52. In this embodiment, filter 34A is used for receiving frequency band B (B-Rx) in Simultaneous Rx / Tx. Furthermore, filter 34A is not limited to a bandpass filter. For example, filter 34A can also be a high-pass filter or a low-pass filter.

[0152] Filter 35A is an example of a fifth filter, and is a bandpass filter having a passband that includes frequency band A. One end of filter 35A is connected to terminal 525 of switching circuit 52, and is connected to filters 31A and 33A in a switchable manner via switching circuit 52. On the other hand, the other end of filter 35A is connected to input / output terminal 101. In this embodiment, filter 35A is used for transmission and reception of frequency band A in Simultaneous Rx / Tx (A-Tx / Rx).

[0153] Filter 36A is an example of the sixth filter and is a bandpass filter having a passband that includes frequency band B. One end of filter 36A is connected to terminal 526 of switching circuit 52, and is connected to filters 32A and 34A in a switchable manner via switching circuit 52. On the other hand, the other end of filter 36A is connected to input / output terminal 101. In this embodiment, filter 36A is used for transmission and reception of frequency band B in Simultaneous Rx / Tx (B-Tx / Rx).

[0154] As such filters 31A to 36A, SAW filters, BAW filters, LC filters, or dielectric filters, or any combination thereof, can be used, and are not limited to them. In particular, in this embodiment, filters 33A and 34A are used for attenuation of the transmitted signal in the Simultaneous Rx / Tx, so LC filters can be used as filters 33A and 34A. In this case, as filters 35A and 36A, it is desirable to use elastic wave filters that include inductors, capacitors, and elastic wave resonators.

[0155] Switching circuit 51A is an example of the first switching circuit, and in addition to terminals 511-513, it also includes terminals 514 and 515. Terminal 514 is an example of the fourteenth terminal, connected to terminal 542 of switching circuit 54A, and connected to low-noise amplifier 21 in a switchable manner via switching circuit 54A. Terminal 515 is an example of the fifteenth terminal, connected to terminal 552 of switching circuit 55A, and connected to low-noise amplifier 22 in a switchable manner via switching circuit 55A.

[0156] In this connection structure, the switch circuit 51A, for example, can connect terminals 511 to terminals 512 and 513 in an exclusive manner, similar to the switch circuit 51 in Embodiment 1, based on control signals from RFIC 3. Furthermore, in this embodiment, the switch circuit 51A can connect terminals 512 to terminals 511 and 514 in an exclusive manner, and can connect terminal 513 to terminals 511 and 515. The switch circuit 51A is, for example, configured as a multi-connection type switch circuit.

[0157] Switching circuit 54A is an example of a fourth switching circuit, connected between low-noise amplifier 21 and filters 31A and 33A. Specifically, switching circuit 54A includes terminals 541 to 543. Terminal 541 is an example of a sixteenth terminal, connected to low-noise amplifier 21. Terminal 542 is an example of a seventeenth terminal, connected to terminal 514 of switching circuit 51A, and connected to filter 31A in a switchable manner via switching circuit 51A. Terminal 543 is an example of an eighteenth terminal, connected to filter 33A.

[0158] In such a connection structure, the switching circuit 54A can, for example, connect terminals 541, 542, and 543 in an exclusive manner based on control signals from RFIC 3. The switching circuit 54A is, for example, constructed from an SPDT-type switching circuit.

[0159] Switching circuit 55A is an example of the fifth switching circuit, connected between low-noise amplifier 22 and filters 32A and 34A. Specifically, switching circuit 55A includes terminals 551 to 553. Terminal 551 is an example of the nineteenth terminal, connected to low-noise amplifier 22. Terminal 552 is an example of the twentieth terminal, connected to terminal 515 of switching circuit 51A, and connected to filter 32A in a switchable manner via switching circuit 51A. Terminal 553 is an example of the twenty-first terminal, connected to filter 34A.

[0160] In such a connection structure, the switching circuit 55A can, for example, connect terminals 551, 552, and 553 in an exclusive manner based on control signals from RFIC 3. The switching circuit 55A is, for example, constructed from an SPDT-type switching circuit.

[0161] [2.2 Connection method within communication device 5A]

[0162] Next, the various connection methods within the communication device 5A will be explained.

[0163] [2.2.1 First Connection Method]

[0164] First, refer to Figure 10 The first connection method will be explained. Figure 10 This diagram illustrates a first connection method of the communication device 5A according to this embodiment.

[0165] In the first connection method, it is possible to simultaneously transmit signals in frequency band A and receive signals in frequency band B. That is, the first connection method is for Simultaneous Rx / Tx connections. For example... Figure 10 As shown, in the first connection method, switch circuit 51A connects terminals 511 and 512, switch circuit 52 connects terminals 521 and 525, and connects terminals 524 and 526, switch circuit 53 connects terminals 531 and 532, and switch circuit 55A connects terminals 551 and 553. Thus, filters 31A and 35A are connected to the transmission path of frequency band A, and filters 34A and 36A are connected to the reception path of frequency band B.

[0166] As a result, the transmitted signal of band A is transmitted from RFIC 3 to antenna 2 via input terminal 111, power amplifier 11, switching circuit 51A, filter 31A, switching circuit 52, filter 35A, input / output terminal 101, and switching circuit 53. The received signal of band B is transmitted from antenna 2 to RFIC 3 via switching circuit 53, input / output terminal 101, filter 36A, switching circuit 52, filter 34A, switching circuit 55A, low-noise amplifier 22, and output terminal 122.

[0167] [2.2.2 Second Connection Method]

[0168] Next, refer to Figure 11 The second connection method will be explained. Figure 11 This diagram illustrates a second connection method of the communication device 5A according to this embodiment.

[0169] In the second connection method, it is possible to simultaneously receive signals from frequency band A and transmit signals from frequency band B. That is, the second connection method is for Simultaneous Rx / Tx connections. For example... Figure 11As shown, in the second connection method, switch circuit 51A connects terminals 511 and 513, switch circuit 52 connects terminals 522 and 526, and connects terminals 523 and 525, switch circuit 53 connects terminals 531 and 532, and switch circuit 54A connects terminals 541 and 543. Thus, filters 32A and 36A are connected to the transmission path of frequency band B, and filters 33A and 35A are connected to the reception path of frequency band A.

[0170] As a result, the transmitted signal of band B is transmitted from RFIC 3 to antenna 2 via input terminal 111, power amplifier 11, switching circuit 51A, filter 32A, switching circuit 52, filter 36A, input / output terminal 101, and switching circuit 53. The received signal of band A is transmitted from antenna 2 to RFIC 3 via switching circuit 53, input / output terminal 101, filter 35A, switching circuit 52, filter 33A, switching circuit 54A, low-noise amplifier 21, and output terminal 121.

[0171] [2.2.3 Third Connection Method]

[0172] Next, refer to Figure 12 The third connection method will be explained. Figure 12 This diagram illustrates a third connection method of the communication device 5A according to this embodiment.

[0173] In the third connection method, it is possible to simultaneously receive signals from frequency band A and frequency band B. For example... Figure 12 As shown, in the third connection method, switch circuit 51A connects terminals 512 and 514, and connects terminals 513 and 515; switch circuit 52 connects terminals 521 and 522 to terminal 527; switch circuit 53 connects terminals 531 and 533; switch circuit 54A connects terminals 541 and 542; and switch circuit 55A connects terminals 551 and 552. Thus, filter 31A is connected to the receiving path of frequency band A, and filter 32A is connected to the receiving path of frequency band B.

[0174] As a result, the received signal in band A is transmitted from antenna 2 to RFIC 3 via switch circuit 53, input / output terminal 102, switch circuit 52, filter 31A, switch circuits 51A and 54A, low-noise amplifier 21, and output terminal 121. The received signal in band B is transmitted from antenna 2 to RFIC 3 via switch circuit 53, input / output terminal 102, switch circuit 52, filter 32A, switch circuits 51A and 55A, low-noise amplifier 22, and output terminal 122.

[0175] Thus, in this embodiment, filters 31A and 32A are used as receiving filters for frequency bands A and B respectively when receiving simultaneously in frequency bands A and B.

[0176] [2.2.4 Fourth Connection Method]

[0177] Next, refer to Figure 13 The fourth connection method will be explained. Figure 13 This diagram illustrates a fourth connection method of the communication device 5A according to this embodiment.

[0178] In the fourth connection mode, signals in frequency band A can be transmitted independently. TDD for frequency band A is achieved by alternately switching between the fourth and fifth connection states. For example... Figure 13 As shown, in the fourth connection method, switch circuit 51A connects terminal 511 to terminal 512, switch circuit 52 connects terminal 521 to terminal 527, and switch circuit 53 connects terminal 531 to terminal 533. Thus, filter 31A is connected to the transmission path of frequency band A.

[0179] As a result, the transmit signal of band A is transmitted from RFIC 3 to antenna 2 via input terminal 111, power amplifier 11, switch circuit 51A, filter 31A, switch circuit 52, input / output terminal 102 and switch circuit 53.

[0180] [2.2.5 Fifth Connection Method]

[0181] Next, refer to Figure 14 The fifth connection method will be explained. Figure 14 This diagram illustrates the fifth connection method of the communication device 5A according to this embodiment.

[0182] In the fifth connection mode, signals in band A can be received independently. TDD in band A is achieved by alternately switching between the fourth and fifth connection states. For example... Figure 14 As shown, in the fifth connection method, switch circuit 51A connects terminal 512 to terminal 514, switch circuit 52 connects terminal 521 to terminal 527, switch circuit 53 connects terminal 531 to terminal 533, and switch circuit 54A connects terminal 541 to terminal 542. Thus, filter 31A is connected to the receiving path of frequency band A.

[0183] As a result, the received signal of band A is transmitted from antenna 2 to RFIC 3 via switching circuit 53, input / output terminal 102, switching circuit 52, filter 31A, switching circuits 51A and 54A, low noise amplifier 21 and output terminal 121.

[0184] Thus, in this embodiment, filter 31A is used as a receiving filter for frequency band A when receiving alone in frequency band A.

[0185] [2.2.6 Sixth Connection Method]

[0186] Next, refer to Figure 15 The sixth connection method will be explained. Figure 15 This diagram illustrates the sixth connection method of the communication device 5A according to this embodiment.

[0187] In the sixth connection mode, signals in frequency band B can be transmitted independently. TDD for frequency band B is achieved by alternately switching between the sixth and seventh connection states. For example... Figure 15 As shown, in the sixth connection method, switch circuit 51A connects terminal 511 to terminal 513, switch circuit 52 connects terminal 522 to terminal 527, and switch circuit 53 connects terminal 531 to terminal 533. Thus, filter 32A is connected to the transmission path of frequency band B.

[0188] As a result, the transmit signal of band B is transmitted from RFIC 3 to antenna 2 via input terminal 111, power amplifier 11, switching circuit 51A, filter 32A, switching circuit 52, input / output terminal 102, and switching circuit 53.

[0189] [2.2.7 Seventh Connection Method]

[0190] Next, refer to Figure 16 The seventh connection method will be explained. Figure 16 This diagram illustrates the seventh connection method of the communication device 5A according to this embodiment.

[0191] In the seventh connection mode, signal reception in band B can be performed independently. TDD in band B is achieved by alternately switching between the sixth and seventh connection states. For example... Figure 16 As shown, in the seventh connection method, switch circuit 51A connects terminals 513 and 515, switch circuit 52 connects terminals 522 and 527, switch circuit 53 connects terminals 531 and 533, and switch circuit 55A connects terminals 551 and 552. Thus, filter 32A is connected to the receiving path of frequency band B.

[0192] As a result, the received signal of band B is transmitted from antenna 2 to RFIC 3 via switching circuit 53, input / output terminal 102, switching circuit 52, filter 32A, switching circuits 51A and 55A, low noise amplifier 22 and output terminal 122.

[0193] Thus, in this embodiment, filter 32A is used as a receiving filter for frequency band B when receiving frequency band B alone.

[0194] [2.3 Summary]

[0195] As described above, the high-frequency circuit 1A according to this embodiment includes: a power amplifier 11; low-noise amplifiers 21 and 22; a filter 31A, which is switchably connected to the power amplifier 11 and has a passband including frequency band A for TDD; a filter 32A, which is switchably connected to the power amplifier 11 and has a passband including frequency band B for TDD, wherein frequency band B and frequency band A can be transmitted and received simultaneously; a filter 33A, which is connected to the low-noise amplifier 21 and has a passband including frequency band A; and a filter 3... 4A, which is connected to low-noise amplifier 22, has a passband including frequency band B; filter 35A, one end of which is switchably connected to filters 31A and 33A respectively, and the other end is connected to input / output terminal 101, filter 35A has a passband including frequency band A; filter 36A, one end of which is switchably connected to filters 32A and 34A respectively, and the other end is connected to input / output terminal 101, filter 36A has a passband including frequency band B; switching circuit 51A, which includes terminal 511 connected to power amplifier 11, Terminals 512, 513, 514, and 515 connected to filter 31A; and a switching circuit 52, including terminals 521, 522, 523, 524, 525, 526 connected to filter 36A, and terminal 527 connected to input / output terminals 102 without passing through filters 35A and 36A. Switching circuit 53 includes a terminal 531 connected to antenna 2, a terminal 532 connected to input / output terminal 101, and a terminal 533 connected to input / output terminal 102; switching circuit 54A includes a terminal 541 connected to low noise amplifier 21, a terminal 542 connected to terminal 514, and a terminal 543 connected to filter 33A; and switching circuit 55A includes a terminal 551 connected to low noise amplifier 22, a terminal 552 connected to terminal 515, and a terminal 553 connected to filter 34A.

[0196] Therefore, similar to the high-frequency circuit 1 according to Embodiment 1, the quality of the received signal can be improved in the Simultaneous Rx / Tx, and the increase in output power and decrease in receiving sensitivity in the power amplifier can be suppressed outside the Simultaneous Rx / Tx. Furthermore, in the high-frequency circuit 1A according to this embodiment, filter 31A can be connected to low-noise amplifier 21 via switching circuits 51A and 54A, and filter 32A can be connected to low-noise amplifier 22 via switching circuits 51A and 55A. Therefore, outside the Simultaneous Rx / Tx, filters 31A and 32A can be used for reception in frequency bands A and B respectively, thus mitigating the performance requirements of filters 33A and 34A and enabling miniaturization of filters 33A and 34A. Furthermore, even if distortion generated in the power amplifier 11 due to insufficient isolation between terminals 511 and 514 of the switching circuit 51A leaks into the switching circuit 54A, the leakage of distortion into the receiving path can be attenuated by the switching circuit 54A, thereby improving the quality of the received signal. Similarly, even if distortion generated in the power amplifier 11 due to insufficient isolation between terminals 511 and 515 of the switching circuit 51A leaks into the switching circuit 55A, the leakage of distortion into the receiving path can be attenuated by the switching circuit 55A, thereby improving the quality of the received signal.

[0197] Alternatively, for example, in the high-frequency circuit 1A according to this embodiment, when transmitting in frequency band A and receiving in frequency band B simultaneously, the switching circuit 51A connects terminal 511 to terminal 512, the switching circuit 52 connects terminal 521 to terminal 525 and terminal 524 to terminal 526, the switching circuit 53 connects terminal 531 to terminal 532, and the switching circuit 55A connects terminal 551 to terminal 553.

[0198] Therefore, in the Simultaneous Rx / Tx based on transmission in band A and reception in band B, filter 31A is connected to input / output terminal 101 via filter 35A, and filter 34A is connected to input / output terminal 101 via filter 36A. Thus, the two filters 34A and 36A can suppress the intrusion of the transmitted signal from band A into the received path of band B, thereby improving the quality of the received signal in band B. For example, if the switching circuit 52 connects terminals 521 and 524 to terminal 527, so that filters 31A and 34A are connected to input / output terminal 102 without passing through filters 35A and 36A, the transmitted signal from band A leaks from filter 34A to the low-noise amplifier 22, and the quality of the received signal in band B deteriorates. In contrast, filters 31A and 34A are connected to input / output terminal 101 via filters 35A and 36A, thereby suppressing the leakage of the transmitted signal of band A to the low-noise amplifier 22 by the two filters 34A and 36A, which can improve the quality of the received signal of band B.

[0199] Alternatively, for example, in the high-frequency circuit 1A according to this embodiment, when receiving frequency band A and transmitting frequency band B simultaneously, the switching circuit 51A connects terminal 511 to terminal 513, the switching circuit 52 connects terminal 522 to terminal 526 and terminal 523 to terminal 525, the switching circuit 53 connects terminal 531 to terminal 532, and the switching circuit 54A connects terminal 541 to terminal 543.

[0200] Therefore, in the Simultaneous Rx / Tx based on reception in band A and transmission in band B, filter 33A is connected to input / output terminal 101 via filter 35A, and filter 32A is connected to input / output terminal 101 via filter 36A. Thus, by using filters 33A and 35A, the intrusion of the transmission signal from band B into the reception path of band A can be suppressed, thereby improving the quality of the received signal in band A. For example, if the switching circuit 52 connects terminals 522 and 523 to terminal 527, so that filters 32A and 33A are connected to input / output terminal 102 without passing through filters 35A and 36A, the transmission signal from band B leaks from filter 33A to the low-noise amplifier 21, degrading the quality of the received signal in band A. In contrast, filters 32A and 33A are connected to input / output terminal 101 via filters 35A and 36A, thereby suppressing the leakage of the transmitted signal of band B to the low-noise amplifier 21 by the two filters 33A and 35A, which can improve the quality of the received signal of band A.

[0201] Alternatively, for example, in the high-frequency circuit 1A according to this embodiment, when receiving frequency band A and frequency band B simultaneously, the switching circuit 51A connects terminal 512 to terminal 514 and terminal 513 to terminal 515, the switching circuit 52 connects terminals 521 and 522 to terminal 527, the switching circuit 53 connects terminal 531 to terminal 533, the switching circuit 54A connects terminal 541 to terminal 542, and the switching circuit 55A connects terminal 551 to terminal 552.

[0202] Therefore, when receiving signals simultaneously in frequency bands A and B, filters 31A and 32A are connected to the input / output terminal 102 without passing through filters 35A and 36A. This avoids signal loss caused by filters 35A and 36A and suppresses the decrease in receiving sensitivity when receiving signals simultaneously in frequency bands A and B. Furthermore, since filters 31A and 32A can be used for receiving signals in frequency bands A and B respectively, the performance requirements for filters 33A and 34A can be mitigated, enabling the miniaturization of filters 33A and 34A.

[0203] Alternatively, for example, in the high-frequency circuit 1A according to this embodiment, the combination of frequency band A and frequency band B may be a combination of Band 40 for LTE or n40 for 5G NR and Band 41 for LTE or n41 for 5G NR, or a combination of Band 39 for LTE or n39 for 5G NR and Band 41 for LTE or n41 for 5G NR.

[0204] This enables improvements in the quality of received signals during Simultaneous Rx / Tx communication in LTE or 5G NR networks.

[0205] Alternatively, for example, in the high-frequency circuit 1A according to this embodiment, at least one of the filters 35A and 36A may be an elastic wave filter including an inductor, a capacitor and an elastic wave resonator.

[0206] Therefore, the attenuation characteristics near the passband can be improved by using an elastic wave resonator, and the attenuation characteristics far from the passband can be improved by using an inductor and a capacitor, thus improving the characteristics of filters 35A and / or 36A.

[0207] Alternatively, for example, in the high-frequency circuit 1A according to this embodiment, at least one of the filters 33A and 34A may be an LC filter.

[0208] This enables the miniaturization of filters 33A and / or 34A.

[0209] In addition, the communication device 5A according to this embodiment includes: an RFIC 3 that processes high-frequency signals; and a high-frequency circuit 1A that transmits high-frequency signals between the RFIC 3 and the antenna 2.

[0210] Therefore, the same effect as the high-frequency circuit 1A can be achieved through the communication device 5A.

[0211] (Implementation Method 3)

[0212] Next, Embodiment 3 will be described. The main difference between this embodiment and the previous embodiments is that the high-frequency circuit includes filters for other frequency bands. Hereinafter, this embodiment will be described with reference to the accompanying drawings, focusing on the differences from Embodiment 2 described above.

[0213] [3.1 Circuit Structure of High-Frequency Circuit 1B]

[0214] Reference Figure 17 The circuit structure of the high-frequency circuit 1B involved in this embodiment will be explained. Figure 17 This is a circuit diagram of the communication device 5B involved in this embodiment.

[0215] also, Figure 17 The circuit structures provided are illustrative; the communication device 5B and the high-frequency circuit 1B can be installed using any of a variety of circuit mounting methods and techniques. Therefore, the descriptions of the communication device 5B and the high-frequency circuit 1B provided below should not be interpreted restrictively.

[0216] The communication device 5B according to this embodiment is the same as the communication device 5A according to embodiment 2, except that it has a high-frequency circuit 1B instead of a high-frequency circuit 1A, so its description is omitted.

[0217] The high-frequency circuit 1B involved in this embodiment includes power amplifiers 11 and 12B, low-noise amplifiers 21, 22 and 23B, filters 31A to 36A and 37B to 39B, switching circuits 51A, 52B, 54A and 55A, input and output terminals 101 and 102, input terminals 111 and 112B, and output terminals 121, 122 and 123B.

[0218] Input terminal 112B is an external connection terminal of the high-frequency circuit 1B and is a high-frequency input terminal. Input terminal 112B is connected externally to RFIC 3 and internally to power amplifier 12B of the high-frequency circuit 1B. Input terminal 112B can receive transmitted signals of frequency band C from RFIC 3.

[0219] Output terminal 123B is an external connection terminal of the high-frequency circuit 1B and is a high-frequency output terminal. Output terminal 123B is connected externally to RFIC 3 and internally to low-noise amplifier 23B within the high-frequency circuit 1B. Output terminal 123B can provide the RFIC 3 with a received signal in frequency band C.

[0220] Power amplifier 12B is an example of a second power amplifier. The input terminal of power amplifier 12B is connected to input terminal 112B. The output terminal of power amplifier 12B is connected to filter 37B. Power amplifier 12B can amplify the transmitted signal in frequency band C provided from RFIC 3 via input terminal 112B using power supplied from a power source (not shown).

[0221] Low-noise amplifier 23B is an example of a third low-noise amplifier. The input of low-noise amplifier 23B is connected to filter 38B. The output of low-noise amplifier 23B is connected to output terminal 123B. Low-noise amplifier 23B can amplify the received signal in frequency band C that has passed through filter 38B using power supplied from a power source (not shown).

[0222] Filter 37B is an example of a seventh filter, and is a bandpass filter having a passband that includes the transmission frequency band C. One end of filter 37B is connected to power amplifier 12B. The other end of filter 37B is connected to terminal 528 of switching circuit 52B, and is connected to input / output terminals 101 and 102 in a switchable manner via switching circuit 52B. Filter 37B is used for transmitting signals in frequency band C (C-Tx).

[0223] Filter 38B is an example of an eighth filter, and is a bandpass filter having a passband that includes the receiving frequency band C. One end of filter 38B is connected to low-noise amplifier 23B. The other end of filter 38B is connected to terminal 528 of switching circuit 52B, and is connected to input / output terminals 101 and 102 in a switchable manner via switching circuit 52B. Filter 38B is used for receiving signals in frequency band C (C-Rx).

[0224] Filter 39B is an example of a ninth filter, and is a low-pass filter having a passband that includes the transmit and receive bands of frequency band C. One end of filter 39B is connected to terminal 529 of switching circuit 52B, and is connected to filters 37B and 38B in a switchable manner via switching circuit 52B. On the other hand, the other end of filter 39B is connected to input / output terminal 101. In this embodiment, filter 39B is used for the transmission and reception of signals in frequency band C in Simultaneous Rx / Tx (C-Tx / Rx).

[0225] As filters 37B to 39B, SAW filters, BAW filters, LC filters, or dielectric filters, or any combination thereof, may also be used, and are not limited to them.

[0226] Switching circuit 52B is an example of a second switching circuit, which includes terminals 521-527, as well as terminals 528 and 529. Terminal 528 is an example of a twenty-second terminal, connected to filters 37B and 38B. Terminal 529 is an example of a twenty-third terminal, connected to filter 39B.

[0227] In this connection structure, the switch circuit 52B, for example, can connect terminals 521-524 to terminals 525-527 based on control signals from RFIC 3, similar to the switch circuits 52 in the above embodiments. Furthermore, the switch circuit 52B can exclusively connect terminals 528 to terminals 527 and 529. The switch circuit 52B is, for example, configured as a multi-connection type switch circuit.

[0228] In addition, the high-frequency circuit 1B may have only one of filters 37B and 38B, or it may not have the other of filters 37B and 38B.

[0229] [3.2 band]

[0230] Here, a specific example of the frequency band C used in the communication device 5B according to this embodiment will be described.

[0231] Frequency band C is an example of a third frequency band, similar to frequency bands A and B, and is predefined by standardization organizations for communication systems built using RAT. In this embodiment, frequency band C is a frequency band used for FDD, and is a combination of frequency bands that can transmit and receive simultaneously with frequency bands A and B.

[0232] For example, as frequency band C, it is possible to use Band1 (1920MHz-2170MHz), Band3 (1710MHz-1880MHz), Band5 (824MHz-894MHz), Band8 (880MHz-915MHz) or Band28 (703MHz-803MHz) for LTE, or n1 (1920MHz-2170MHz), n3 (1710MHz-1880MHz), n5 (824MHz-894MHz), n8 (880MHz-915MHz) or n28 (703MHz-803MHz) for 5G NR.

[0233] Furthermore, band C is not limited to the band used for FDD. Band C can also be used for TDD, SUL (Supplementary Uplink), or SDL (Supplementary Downlink). If band C is used for SUL, filter 38B may not be included in high-frequency circuit 1B; if band C is used for SDL, filter 37B may not be included in high-frequency circuit 1B.

[0234] [3.3 Connection method within communication device 5B]

[0235] Next, the various connection methods within the communication device 5B will be explained.

[0236] [3.3.1 First Connection Method]

[0237] First, refer to Figure 18 The first connection method will be explained. Figure 18 This diagram illustrates the first connection method of the communication device 5B according to this embodiment.

[0238] In the first connection method, it is possible to simultaneously transmit signals in frequency band A, receive signals in frequency band B, and transmit and receive signals in frequency band C. That is, the first connection method is for Simultaneous Rx / Tx connections. For example... Figure 18 As shown, in the first connection method, switch circuit 51A connects terminals 511 and 512, switch circuit 52B connects terminals 521 and 525, and connects terminals 524 and 526, and connects terminals 528 and 529, switch circuit 53 connects terminals 531 and 532, and switch circuit 55A connects terminals 551 and 553. Thus, filters 31A and 35A are connected to the transmission path of frequency band A, filters 34A and 36A are connected to the reception path of frequency band B, filters 37B and 39B are connected to the transmission path of frequency band C, and filters 38B and 39B are connected to the reception path of frequency band C.

[0239] As a result, the transmit signal of band A is transmitted from RFIC 3 to antenna 2 via input terminal 111, power amplifier 11, switch circuit 51A, filter 31A, switch circuit 52B, filter 35A, input / output terminal 101, and switch circuit 53. The receive signal of band B is transmitted from antenna 2 to RFIC 3 via switch circuit 53, input / output terminal 101, filter 36A, switch circuit 52B, filter 34A, switch circuit 55A, low-noise amplifier 22, and output terminal 122. The transmit signal of band C is transmitted from RFIC 3 to antenna 2 via input terminal 112B, power amplifier 12B, filter 37B, switch circuit 52B, filter 39B, input / output terminal 101, and switch circuit 53. The receive signal of band C is transmitted from antenna 2 to RFIC 3 via switch circuit 53, input / output terminal 101, filter 39B, switch circuit 52B, filter 38B, low-noise amplifier 23B, and output terminal 123B.

[0240] [3.3.2 Second Connection Method]

[0241] Next, refer to Figure 19 The second connection method will be explained. Figure 19 This diagram illustrates a second connection method of the communication device 5B according to this embodiment.

[0242] In the second connection method, it is possible to simultaneously receive signals in frequency band A, transmit signals in frequency band B, and transmit and receive signals in frequency band C. That is, the second connection method is for Simultaneous Rx / Tx connections. For example... Figure 19 As shown, in the second connection method, switch circuit 51A connects terminals 511 and 513, switch circuit 52B connects terminals 522 and 526, and connects terminals 523 and 525, and connects terminals 528 and 529, switch circuit 53 connects terminals 531 and 532, and switch circuit 54A connects terminals 541 and 543. Thus, filters 32A and 36A are connected to the transmission path of frequency band B, filters 33A and 35A are connected to the reception path of frequency band A, filters 37B and 39B are connected to the transmission path of frequency band C, and filters 38B and 39B are connected to the reception path of frequency band C.

[0243] As a result, the transmit signal of band B is transmitted from RFIC 3 to antenna 2 via input terminal 111, power amplifier 11, switch circuit 51A, filter 32A, switch circuit 52B, filter 36A, input / output terminal 101, and switch circuit 53. The receive signal of band A is transmitted from antenna 2 to RFIC 3 via switch circuit 53, input / output terminal 101, filter 35A, switch circuit 52B, filter 33A, switch circuit 54A, low-noise amplifier 21, and output terminal 121. The transmit signal of band C is transmitted from RFIC 3 to antenna 2 via input terminal 112B, power amplifier 12B, filter 37B, switch circuit 52B, filter 39B, input / output terminal 101, and switch circuit 53. The receive signal of band C is transmitted from antenna 2 to RFIC 3 via switch circuit 53, input / output terminal 101, filter 39B, switch circuit 52B, filter 38B, low-noise amplifier 23B, and output terminal 123B.

[0244] [3.3.3 Third Connection Method]

[0245] Next, refer to Figure 20 The third connection method will be explained. Figure 20 This diagram illustrates a third connection method of the communication device 5B according to this embodiment.

[0246] In the third connection method, it is possible to simultaneously receive signals from frequency band A and frequency band B. For example... Figure 20 As shown, in the third connection method, switch circuit 51A connects terminals 512 and 514, and connects terminals 513 and 515; switch circuit 52B connects terminals 521, 522, and 528 to terminal 527; switch circuit 53 connects terminals 531 and 533; switch circuit 54A connects terminals 541 and 542; and switch circuit 55A connects terminals 551 and 552. Thus, filter 31A is connected to the receiving path of frequency band A, filter 32A is connected to the receiving path of frequency band B, filter 37B is connected to the transmitting path of frequency band C, and filter 38B is connected to the receiving path of frequency band C. The transmitting signal of frequency band C is transmitted from RFIC3 to antenna 2 via input terminal 112B, power amplifier 12B, filter 37B, switch circuit 52B, input / output terminal 102, and switch circuit 53. The received signal in band C is transmitted from antenna 2 to RFIC 3 via switching circuit 53, input / output terminal 102, switching circuit 52B, filter 38B, low-noise amplifier 23B and output terminal 123B.

[0247] As a result, the received signal in band A is transmitted from antenna 2 to RFIC 3 via switch circuit 53, input / output terminal 102, switch circuit 52B, filter 31A, switch circuits 51A and 54A, low-noise amplifier 21, and output terminal 121. The received signal in band B is transmitted from antenna 2 to RFIC 3 via switch circuit 53, input / output terminal 102, switch circuit 52B, filter 32A, switch circuits 51A and 55A, low-noise amplifier 22, and output terminal 122.

[0248] Furthermore, the separate transmission and reception of frequency bands A and B are the same as in Embodiment 2 described above, therefore their illustrations and descriptions are omitted. Similarly, the separate transmission and reception of frequency band C are also similar to the third connection method, therefore their illustrations and descriptions are omitted.

[0249] [3.4 Summary]

[0250] As described above, the high-frequency circuit 1B according to this embodiment includes: power amplifiers 11 and 12B; low-noise amplifiers 21, 22, and 23B; a filter 31A, which is switchably connected to the power amplifier 11 and has a passband including frequency band A for TDD; a filter 32A, which is switchably connected to the power amplifier 11 and has a passband including frequency band B for TDD, wherein frequency band B and frequency band A can be transmitted and received simultaneously; a filter 33A, which is connected to the low-noise amplifier 21 and has a passband including frequency band A; a filter 34A, which is connected to the low-noise amplifier 22 and has a passband including frequency band B; and a filter 35A, one end of which is connected to the filter... Filters 31A and 33A are connected in a switchable manner, with their other ends connected to input / output terminal 101. Filter 35A has a passband covering frequency band A. Filter 36A has one end connected in a switchable manner to filters 32A and 34A, with its other end connected to input / output terminal 101. Filter 36A has a passband covering frequency band B. Filter 37B is connected to power amplifier 12B and has a passband covering the transmit frequency band of frequency band C. Filter 38B is connected to low-noise amplifier 23B and has a passband covering the receive frequency band of frequency band C. Filter 39B has one end connected in a switchable manner to filters 37B and 38B, with its other end connected to input / output terminal 101. The connection includes: filter 39B having a passband encompassing the transmit and receive bands of frequency band C; switching circuit 51A including terminal 511 connected to power amplifier 11, terminal 512 connected to filter 31A, terminal 513 connected to filter 32A, and terminals 514 and 515; switching circuit 52B including terminal 521 connected to filter 31A, terminal 522 connected to filter 32A, terminal 523 connected to filter 33A, terminal 524 connected to filter 34A, terminal 525 connected to filter 35A, terminal 526 connected to filter 36A, and connected to input / output terminal 1 in a manner not via filters 35A and 36A. Terminal 527 connected to 02, terminal 528 connected to filters 37B and 38B, and terminal 529 connected to filter 39B; switch circuit 53, which includes terminal 531 connected to antenna 2, terminal 532 connected to input / output terminal 101, and terminal 533 connected to input / output terminal 102; switch circuit 54A, which includes terminal 541 connected to low noise amplifier 21, terminal 542 connected to terminal 514, and terminal 543 connected to filter 33A; and switch circuit 55A, which includes terminal 551 connected to low noise amplifier 22, terminal 552 connected to terminal 515, and terminal 553 connected to filter 34A.

[0251] Therefore, similar to the high-frequency circuit 1 according to Embodiment 1, the quality of the received signal can be improved in the Simultaneous Rx / Tx, and the increase in output power and the decrease in receiving sensitivity in the power amplifier can be suppressed outside the Simultaneous Rx / Tx. Furthermore, similar to the high-frequency circuit 1A according to Embodiment 2, the performance requirements of filters 33A and 34A can be mitigated, and the miniaturization of filters 33A and 34A can be achieved. Moreover, the transmission and reception of signals in frequency band C can be supported in the Simultaneous Rx / Tx based on frequency bands A and B.

[0252] Alternatively, for example, in the high-frequency circuit 1B according to this embodiment, when transmitting in frequency band A, receiving in frequency band B, and transmitting and receiving in frequency band C are performed simultaneously, the switching circuit 51A connects terminal 511 to terminal 512, the switching circuit 52B connects terminal 521 to terminal 525, and connects terminal 524 to terminal 526, and connects terminal 528 to terminal 529, the switching circuit 53 connects terminal 531 to terminal 532, and the switching circuit 55A connects terminal 551 to terminal 553.

[0253] Therefore, in the Simultaneous Rx / Tx based on transmission in band A and reception in band B, filter 31A is connected to input / output terminal 101 via filter 35A, and filter 34A is connected to input / output terminal 101 via filter 36A. Thus, the two filters 34A and 36A can suppress the intrusion of the transmitted signal from band A into the received path of band B, thereby improving the quality of the received signal in band B. For example, if the switching circuit 52 connects terminals 521 and 524 to terminal 527, so that filters 31A and 34A are connected to input / output terminal 102 without passing through filters 35A and 36A, the transmitted signal from band A leaks from filter 34A to the low-noise amplifier 22, and the quality of the received signal in band B deteriorates. In contrast, filters 31A and 34A are connected to input / output terminal 101 via filters 35A and 36A, thereby suppressing leakage of the transmitted signal from band A to the low-noise amplifier 22 by the two filters 34A and 36A, which improves the quality of the received signal from band B. Furthermore, filters 37B to 39B can also be used to support the transmission and reception of band C.

[0254] Alternatively, for example, in the high-frequency circuit 1B according to this embodiment, when receiving frequency band A, transmitting frequency band B, and transmitting and receiving frequency band C are performed simultaneously, the switching circuit 51A connects terminal 511 to terminal 513, the switching circuit 52B connects terminal 522 to terminal 526, and connects terminal 523 to terminal 525, and connects terminal 528 to terminal 529, the switching circuit 53 connects terminal 531 to terminal 532, and the switching circuit 54A connects terminal 541 to terminal 543.

[0255] Therefore, in the Simultaneous Rx / Tx based on reception in band A and transmission in band B, filter 33A is connected to input / output terminal 101 via filter 35A, and filter 32A is connected to input / output terminal 101 via filter 36A. Thus, by using filters 33A and 35A, the intrusion of the transmission signal from band B into the reception path of band A can be suppressed, thereby improving the quality of the received signal in band A. For example, if the switching circuit 52B connects terminals 522 and 523 to terminal 527, so that filters 32A and 33A are connected to input / output terminal 102 without passing through filters 35A and 36A, the transmission signal from band B leaks from filter 33A to the low-noise amplifier 21, degrading the quality of the received signal in band A. In contrast, filters 32A and 33A are connected to input / output terminal 101 via filters 35A and 36A, thereby suppressing leakage of the transmitted signal from band B to the low-noise amplifier 21 by the two filters 33A and 35A, which improves the quality of the received signal from band A. Furthermore, filters 37B to 39B can also be used to support the transmission and reception of band C.

[0256] Alternatively, for example, in the high-frequency circuit 1B according to this embodiment, when receiving frequency band A, receiving frequency band B, and transmitting and receiving frequency band C are performed simultaneously, the switching circuit 51A connects terminal 512 to terminal 514 and connects terminal 513 to terminal 515, the switching circuit 52B connects terminals 521, 522, and 528 to terminal 527, the switching circuit 53 connects terminal 531 to terminal 533, the switching circuit 54A connects terminal 541 to terminal 542, and the switching circuit 55A connects terminal 551 to terminal 552.

[0257] Therefore, when transmitting and receiving simultaneously in frequency bands A through C, filters 31A and 32A are connected to the input / output terminal 102 without passing through filters 35A and 36A. This avoids signal loss caused by filters 35A and 36A and suppresses the decrease in receiving sensitivity when simultaneously receiving in frequency bands A and B. Furthermore, since filters 31A and 32A can be used for receiving in frequency bands A and B respectively, the performance requirements for filters 33A and 34A can be mitigated, enabling miniaturization of filters 33A and 34A. Additionally, filters 37B and 38B are connected to the input / output terminal 102 without passing through filter 39B. This avoids signal loss caused by filter 39B and suppresses the increase in output power of the transmitted signal in frequency band C required by the power amplifier 12B, as well as the decrease in receiving sensitivity in frequency band C.

[0258] Additionally, for example, in the high-frequency circuit 1B according to this embodiment, the combination of frequency bands A and B can also be a combination of Band 40 for LTE or n40 for 5G NR and Band 41 for LTE or n41 for 5G NR, or a combination of Band 39 for LTE or n39 for 5G NR and Band 41 for LTE or n41 for 5G NR. Frequency band C can also be Band 1, Band 3, Band 5, Band 8 or Band 28 for LTE, or n1, n3, n5, n8 or n28 for 5G NR.

[0259] This enables improvements in the quality of received signals during Simultaneous Rx / Tx communication in LTE or 5G NR networks.

[0260] Alternatively, for example, in the high-frequency circuit 1B according to this embodiment, at least one of the filters 35A and 36A may be an elastic wave filter including an inductor, a capacitor and an elastic wave resonator.

[0261] Therefore, the attenuation characteristics near the passband can be improved by using an elastic wave resonator, and the attenuation characteristics far from the passband can be improved by using an inductor and a capacitor, thus improving the characteristics of filters 35A and / or 36A.

[0262] Alternatively, for example, in the high-frequency circuit 1B according to this embodiment, at least one of the filters 33A and 34A may be an LC filter.

[0263] This enables the miniaturization of filters 33A and / or 34A.

[0264] In addition, the communication device 5B according to this embodiment includes: an RFIC 3 that processes high-frequency signals; and a high-frequency circuit 1B that transmits high-frequency signals between the RFIC 3 and the antenna 2.

[0265] Therefore, the same effect as the high-frequency circuit 1B can be achieved through the communication device 5B.

[0266] (Implementation Method 4)

[0267] Next, Embodiment 4 will be described. In this embodiment, the connection structure of the filter and the switching circuit differs from that of Embodiment 1 described above. Hereinafter, this embodiment will be described with reference to the accompanying drawings, focusing on the differences from Embodiment 1.

[0268] [4.1 Circuit Structure of High-Frequency Circuit 1C]

[0269] Reference Figure 21 The circuit structure of the high-frequency circuit 1C involved in this embodiment will be explained. Figure 21 This is a circuit diagram of the communication device 5C involved in this embodiment.

[0270] also, Figure 21 The circuit structures described below are illustrative. The communication device 5C and the high-frequency circuit 1C can be installed using any of a wide variety of circuit mounting methods and techniques. Therefore, the descriptions of the communication device 5C and the high-frequency circuit 1C provided below should not be interpreted restrictively.

[0271] The communication device 5C described in this embodiment is the same as the communication device 5 described in Embodiment 1, except that it has a high-frequency circuit 1C instead of a high-frequency circuit 1A and does not have a switching circuit 53. Therefore, its description is omitted.

[0272] The high-frequency circuit 1C involved in this embodiment includes power amplifiers 11C and 12C, low-noise amplifiers 21C, 22C, 23C and 24C, filters 31C, 32C, 33C, 34C, 35C, 36C, 41C, 42C, 43C and 44C, switching circuits 51C, 52C, 53C, 54C and 55C, antenna connection terminal 100C, input terminals 111C and 112C, and output terminals 121C, 122C, 123C and 124C.

[0273] Antenna connection terminal 100C is an external connection terminal of high-frequency circuit 1C and is connected to antenna 2. Specifically, antenna connection terminal 100C is connected to antenna 2 externally to high-frequency circuit 1C and to switching circuit 51C internally to high-frequency circuit 1C.

[0274] Input terminal 111C is an external connection terminal of the high-frequency circuit 1C, and is a high-frequency input terminal. Input terminal 111C is connected externally to RFIC 3 and internally to power amplifier 11C. Input terminal 111C can receive the transmitted signal of frequency band A from RFIC 3.

[0275] Input terminal 112C is an external connection terminal of high-frequency circuit 1C, and is a high-frequency input terminal. Input terminal 112C is connected externally to RFIC 3 and internally to power amplifier 12C of high-frequency circuit 1C. Input terminal 112C can receive the transmitted signal of frequency band B from RFIC 3.

[0276] Output terminal 121C is an external connection terminal of high-frequency circuit 1C and is a high-frequency output terminal. Output terminal 121C is connected externally to RFIC 3 and internally to low-noise amplifier 21C. Output terminal 121C can provide the RFIC 3 with a received signal in band A.

[0277] Output terminal 122C is an external connection terminal of high-frequency circuit 1C and is a high-frequency output terminal. Output terminal 122C is connected externally to RFIC 3 and internally to low-noise amplifier 22C of high-frequency circuit 1C. Output terminal 122C can provide the RFIC 3 with the received signal of frequency band B.

[0278] Output terminal 123C is an external connection terminal of high-frequency circuit 1C and is a high-frequency output terminal. Output terminal 123C is connected externally to RFIC 3 and internally to low-noise amplifier 23C within high-frequency circuit 1C. Output terminal 123C can provide the RFIC 3 with the received signal of frequency band C.

[0279] Output terminal 124C is an external connection terminal of high-frequency circuit 1C and is a high-frequency output terminal. Output terminal 124C is connected externally to RFIC 3 and internally to low-noise amplifier 24C of high-frequency circuit 1C. Output terminal 124C can provide the RFIC 3 with the received signal of frequency band D.

[0280] Power amplifier 11C is an example of a first power amplifier. The input terminal of power amplifier 11C is connected to input terminal 111C. The output terminal of power amplifier 11C is connected to filter 31C. Power amplifier 11C can amplify the transmitted signal in frequency band A provided from RFIC 3 via input terminal 111C using power supplied from a power source (not shown). Furthermore, power amplifier 11C may be partially or entirely excluded from the high-frequency circuit 1C. In this case, power amplifier 11C may be partially or entirely connected between RFIC 3 and input terminal 111C, or it may be included within RFIC 3.

[0281] Power amplifier 12C is an example of a second power amplifier. The input terminal of power amplifier 12C is connected to input terminal 112C. The output terminal of power amplifier 12C is connected to filter 33C. Power amplifier 12C can amplify the transmitted signal in frequency band B provided from RFIC 3 via input terminal 112C using power supplied from a power source (not shown). Furthermore, power amplifier 12C may be partially or entirely excluded from the high-frequency circuit 1C. In this case, power amplifier 12C may be partially or entirely connected between RFIC 3 and input terminal 112C, or it may be included within RFIC 3.

[0282] Low-noise amplifier 21C is an example of a first low-noise amplifier. The input terminal of low-noise amplifier 21C is connected to filter 32C. The output terminal of low-noise amplifier 21C is connected to output terminal 121C. Low-noise amplifier 21C can amplify the received signal in frequency band A that has passed through filter 32C using power supplied from a power source (not shown). Furthermore, low-noise amplifier 21C may be partially or entirely excluded from high-frequency circuit 1C. In this case, low-noise amplifier 21C may be partially or entirely connected between RFIC 3 and output terminal 121C, or it may be included within RFIC 3.

[0283] Low-noise amplifier 22C is an example of a second low-noise amplifier. The input of low-noise amplifier 22C is connected to filter 34C. The output of low-noise amplifier 22C is connected to output terminal 122C. Low-noise amplifier 22C can amplify the received signal in frequency band B that has passed through filter 34C using power supplied from a power source (not shown). Furthermore, low-noise amplifier 22C may be partially or entirely excluded from the high-frequency circuit 1C. In this case, low-noise amplifier 22C may be partially or entirely connected between RFIC 3 and output terminal 122C, or it may be included within RFIC 3.

[0284] Low-noise amplifier 23C is an example of a third low-noise amplifier. The input of low-noise amplifier 23C is connected to filter 35C. The output of low-noise amplifier 23C is connected to output terminal 123C. Low-noise amplifier 23C can amplify the received signal in frequency band C that has passed through filter 35C using power supplied from a power source (not shown). Furthermore, low-noise amplifier 23C may be partially or entirely excluded from the high-frequency circuit 1C. In this case, low-noise amplifier 23C may be partially or entirely connected between RFIC 3 and output terminal 123C, or it may be included within RFIC 3.

[0285] Low-noise amplifier 24C is an example of a fourth low-noise amplifier. The input of low-noise amplifier 24C is connected to filter 36C. The output of low-noise amplifier 24C is connected to output terminal 124C. Low-noise amplifier 24C can amplify the received signal in frequency band D that has passed through filter 36C using power supplied from a power source (not shown). Furthermore, low-noise amplifier 24C may be partially or entirely excluded from high-frequency circuit 1C. In this case, low-noise amplifier 24C may be partially or entirely connected between RFIC 3 and output terminal 124C, or it may be included within RFIC 3.

[0286] Filter 31C, an example of the first filter, is a bandpass filter having a passband that includes the transmission frequency band A. One end of filter 31C is connected to power amplifier 11C. The other end of filter 31C is connected to terminal 512C of switching circuit 51C, and is switchably connected to terminal 511C of switching circuit 51C via switching circuit 52C and filter 41C. Filter 31C is used for transmission in frequency band A (A-Tx).

[0287] Filter 32C, an example of the first filter, is a bandpass filter having a passband that includes the receiving frequency band A. One end of filter 32C is connected to low-noise amplifier 21C. The other end of filter 32C is connected to terminal 514C of switching circuit 51C, and is switchably connected to terminal 513C of switching circuit 51C via switching circuit 53C and filter 42C. Filter 32C is used for receiving frequency band A (A-Rx).

[0288] Filter 33C is an example of a second filter, and is a bandpass filter having a passband that includes the transmission band of frequency band B. One end of filter 33C is connected to power amplifier 12C. On the other hand, the other end of filter 33C is connected to terminal 516C of switching circuit 51C, and is switchably connected to terminal 515C of switching circuit 51C via switching circuit 54C and filter 43C. Filter 33C is used for transmission in frequency band B (B-Tx).

[0289] Filter 34C, an example of a second filter, is a bandpass filter having a passband that includes the receiving frequency band B. One end of filter 34C is connected to low-noise amplifier 22C. The other end of filter 34C is connected to terminal 518C of switching circuit 51C, and is switchably connected to terminal 517C of switching circuit 51C via switching circuit 55C and filter 44C. Filter 34C is used for receiving frequency band B (B-Rx).

[0290] Filter 35C is a bandpass filter having a passband that includes the receiving frequency band C. One end of filter 35C is connected to low-noise amplifier 23C. On the other hand, the other end of filter 35C is connected to terminal 519C of switching circuit 51C. Filter 35C is used for receiving frequency band C (C-Rx). Alternatively, filter 35C may not be included in high-frequency circuit 1C.

[0291] Filter 36C is a bandpass filter having a passband that includes the receiving frequency band D. One end of filter 36C is connected to low-noise amplifier 24C. On the other hand, the other end of filter 36C is connected to terminal 519C of switching circuit 51C. Filter 36C is used for receiving frequency band D (D-Rx). Alternatively, filter 36C may not be included in high-frequency circuit 1C.

[0292] Filter 41C is an example of a third filter, and is a low-pass filter having an attenuation band that includes frequency band B. One end of filter 41C is connected to terminal 511C of switching circuit 51C. On the other hand, the other end of filter 41C is connected to terminal 521C of switching circuit 52C. Filter 41C has a passband that includes frequency band A and is used for transmitting signals in frequency band A. Furthermore, filter 41C is not limited to a low-pass filter. For example, filter 41C could also be a band-stop filter or a band-pass filter.

[0293] Filter 42C is an example of a third filter, and is a low-pass filter having an attenuation band that includes frequency band B. One end of filter 42C is connected to terminal 513C of switching circuit 51C. On the other hand, the other end of filter 42C is connected to terminal 531C of switching circuit 53C. Filter 42C has a passband that includes frequency band A for receiving signals in frequency band A. Furthermore, filter 42C is not limited to a low-pass filter. For example, filter 42C could also be a band-stop filter or a band-pass filter.

[0294] Alternatively, filters 41C and 42C may not be included in the high-frequency circuit 1C, or only one of filters 41C and 42C may be included in the high-frequency circuit 1C.

[0295] Filter 43C is a high-pass filter having an attenuation band covering frequency band A. One end of filter 43C is connected to terminal 515C of switching circuit 51C. The other end of filter 43C is connected to terminal 541C of switching circuit 54C. Filter 43C has a passband covering frequency band B for transmitting signals in frequency band B. Furthermore, filter 43C is not limited to a high-pass filter. For example, filter 43C could also be a band-stop filter or a band-pass filter. Additionally, filter 43C may not be included in high-frequency circuit 1C.

[0296] Filter 44C is a high-pass filter having an attenuation band covering frequency band A. One end of filter 44C is connected to terminal 517C of switching circuit 51C. The other end of filter 44C is connected to terminal 551C of switching circuit 55C. Filter 44C has a passband covering frequency band B for receiving signals in frequency band B. Furthermore, filter 44C is not limited to a high-pass filter. For example, filter 44C can also be a band-stop filter or a band-pass filter. Additionally, filter 44C may not be included in high-frequency circuit 1C.

[0297] As filters 31C to 36C and 41C to 44C, SAW filters, BAW filters, LC filters or dielectric filters, or any combination thereof, may also be used, and are not limited to them.

[0298] Switching circuit 51C is an example of a first switching circuit, including terminals 510C to 519C. Terminal 510C is an example of a first terminal, connected to antenna connection terminal 100C. Terminal 511C is an example of a fourth terminal, connected to filter 41C. Terminal 512C is an example of a second terminal, connected to filter 31C. Terminal 513C is an example of a fourth terminal, connected to filter 42C. Furthermore, if filter 42C is not included in high-frequency circuit 1C, terminal 513C may also be excluded from switching circuit 51C. Terminal 514C is an example of a second terminal, connected to filter 32C. Terminal 515C is connected to filter 43C. Terminal 516C is an example of a third terminal, connected to filter 33C. Terminal 517C is connected to filter 44C. Terminal 518C is an example of a third terminal, connected to filter 34C. Terminal 519C is connected to filters 35C and 36C.

[0299] In such a connection structure, the switching circuit 51C can, for example, connect terminal 510C to terminals 511C to 519C based on a control signal from RFIC 3. The switching circuit 51C is, for example, a multi-connection type switching circuit.

[0300] Switching circuit 52C is an example of a second switching circuit, including terminals 521C and 522C. Terminal 521C is an example of a fifth terminal, connected to filter 41C. Terminal 522C is an example of a sixth terminal, connected to filter 31C.

[0301] In such a connection structure, the switching circuit 52C can, for example, connect terminals 521C and 522C based on control signals from RFIC 3. The switching circuit 52C is, for example, an SPST (Single-Pole Single-Throw) type switching circuit. Furthermore, if the filter 41C is not included in the high-frequency circuit 1C, the switching circuit 52C may also be excluded from the high-frequency circuit 1C.

[0302] Switching circuit 53C is an example of a second switching circuit, including terminals 531C and 532C. Terminal 531C is an example of a fifth terminal, connected to filter 42C. Terminal 532C is an example of a sixth terminal, connected to filter 32C.

[0303] In such a connection structure, the switching circuit 53C can, for example, connect terminals 531C and 532C based on control signals from RFIC 3. The switching circuit 53C is, for example, an SPST-type switching circuit. Furthermore, if the filter 42C is not included in the high-frequency circuit 1C, the switching circuit 53C may also be excluded from the high-frequency circuit 1C.

[0304] The switching circuit 54C includes terminals 541C and 542C. Terminal 541C is connected to filter 43C. Terminal 542C is connected to filter 33C.

[0305] In such a connection structure, the switching circuit 54C can, for example, connect terminals 541C and 542C based on control signals from RFIC 3. The switching circuit 54C is, for example, an SPST-type switching circuit. Furthermore, if the filter 43C is not included in the high-frequency circuit 1C, the switching circuit 54C may also be excluded from the high-frequency circuit 1C.

[0306] The switching circuit 55C includes terminals 551C and 552C. Terminal 551C is connected to filter 44C. Terminal 552C is connected to filter 34C.

[0307] In such a connection structure, the switching circuit 55C can, for example, connect terminals 551C and 552C based on control signals from RFIC 3. The switching circuit 55C is, for example, an SPST-type switching circuit. Furthermore, if the filter 44C is not included in the high-frequency circuit 1C, the switching circuit 55C may also be excluded from the high-frequency circuit 1C.

[0308] Similar to frequency bands A through C, frequency band D is predefined by standardization organizations for communication systems built using RAT. In this embodiment, frequency band D is an FDD frequency band different from frequency band C, and it is a frequency band that can transmit and receive simultaneously with frequency bands A and B.

[0309] For example, as frequency band D, it is possible to use Band1 (1920MHz-2170MHz), Band3 (1710MHz-1880MHz), Band5 (824MHz-894MHz), Band8 (880MHz-915MHz) or Band28 (703MHz-803MHz) for LTE, or n1 (1920MHz-2170MHz), n3 (1710MHz-1880MHz), n5 (824MHz-894MHz), n8 (880MHz-915MHz) or n28 (703MHz-803MHz) for 5G NR.

[0310] Furthermore, band D is not limited to the band used for FDD. Band D can also be the band used for TDD or SDL.

[0311] [4.2 Communication Mode of Communication Device 5C]

[0312] Next, the communication mode of the communication device 5C will be explained.

[0313] [4.2.1 First Mode]

[0314] First, refer to Figure 22 The first mode will be explained. Figure 22 This is a diagram showing a first mode of the communication device 5C according to this embodiment.

[0315] In the first mode, signal transmission in frequency band A and signal reception in frequency band B are performed simultaneously. That is, the first mode corresponds to the first connection method in embodiments 1-3 described above, and is a communication mode for Simultaneous Rx / Tx. For example... Figure 22 As shown, in the first mode, switch circuit 51C connects terminal 510C to terminals 511C and 517C, but does not connect terminal 510C to terminals 512C-516C, 518C, and 519C. Switch circuit 52C connects terminal 521C to terminal 522C, and switch circuit 55C connects terminal 551C to terminal 552C. That is, switch circuits 52C and 55C are closed. At this time, switch circuits 53C and 54C are open. As a result, filters 31C and 41C are connected to the transmission path of frequency band A, and filters 34C and 44C are connected to the reception path of frequency band B.

[0316] As a result, the transmit signal of band A is transmitted from RFIC 3 to antenna 2 via input terminal 111C, power amplifier 11C, filter 31C, switch circuit 52C, filter 41C, switch circuit 51C again, and antenna connection terminal 100C. The receive signal of band B is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 100C, switch circuit 51C, filter 44C, switch circuit 55C, filter 34C, low noise amplifier 22C, and output terminal 122C.

[0317] [4.2.2 Second Mode]

[0318] Next, refer to Figure 23 The second mode will be explained. Figure 23 This is a diagram showing a second mode of the communication device 5C according to this embodiment.

[0319] In the second mode, signal transmission in frequency band B and signal reception in frequency band A are performed simultaneously. That is, the second mode corresponds to the second connection method in embodiments 1-3 described above, and is a communication mode for Simultaneous Rx / Tx. For example... Figure 23As shown, in the second mode, switch circuit 51C connects terminal 510C to terminals 513C and 515C, but does not connect terminal 510C to terminals 512C, 514C, and 516C to 519C. Switch circuit 53C connects terminal 531C to terminal 532C, and switch circuit 54C connects terminal 541C to terminal 542C. That is, switch circuits 53C and 54C are closed. At this time, switch circuits 52C and 55C are open. As a result, filters 32C and 42C are connected to the receiving path of frequency band A, and filters 33C and 43C are connected to the transmitting path of frequency band B.

[0320] As a result, the transmit signal of band B is transmitted from RFIC 3 to antenna 2 via input terminal 112C, power amplifier 12C, filter 33C, switching circuit 54C, filter 43C, switching circuit 51C, and antenna connection terminal 100C. The receive signal of band A is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 100C, switching circuit 51C, filter 42C, switching circuit 53C, filter 32C, low noise amplifier 21C, and output terminal 121C.

[0321] [4.2.3 Third Mode]

[0322] Next, refer to Figure 24 The third mode will be explained. Figure 24 This diagram illustrates the third mode of the communication device 5C according to this embodiment.

[0323] In the third mode, the transmission and reception of signals in frequency band A are switched according to time, while signals in frequency bands C and D are received. For example... Figure 24 As shown, in the third mode, the switching circuit 51C connects terminal 510C to terminal 519C, and switches the connection of terminal 510C between terminals 512C and 514C. At this time, the switching circuit 51C does not connect terminal 510C to terminals 511C, 513C, and 515C to 518C. Therefore, filter 31C is connected to the transmission path of frequency band A, filter 32C is connected to the reception path of frequency band A, and filters 35C and 36C are connected to the reception paths of frequency bands C and D, respectively.

[0324] As a result, the transmit signal of band A is transmitted from RFIC 3 to antenna 2 via input terminal 111C, power amplifier 11C, filter 31C, switching circuit 51C, and antenna connection terminal 100C. The receive signal of band A is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 100C, switching circuit 51C, filter 32C, low noise amplifier 21C, and output terminal 121C. The receive signal of band C is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 100C, switching circuit 51C, filter 35C, low noise amplifier 23C, and output terminal 123C. The receive signal of band D is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 100C, switching circuit 51C, filter 36C, low noise amplifier 24C, and output terminal 124C.

[0325] [4.2.4 Fourth Mode]

[0326] Next, refer to Figure 25 The fourth mode will be explained. Figure 25 This diagram illustrates the fourth mode of the communication device 5C according to this embodiment.

[0327] In the fourth mode, the transmission and reception of signals in frequency band B are switched according to time, while signals in frequency bands C and D are received. For example... Figure 25 As shown, in the fourth mode, the switching circuit 51C connects terminal 510C to terminal 519C, and switches the connection of terminal 510C between terminals 516C and 518C. At this time, the switching circuit 51C does not connect terminal 510C to terminals 511C-515C and 517C. Therefore, filter 33C is connected to the transmit path of frequency band B, filter 34C is connected to the receive path of frequency band B, and filters 35C and 36C are connected to the receive paths of frequency bands C and D, respectively.

[0328] As a result, the transmit signal of band B is transmitted from RFIC 3 to antenna 2 via input terminal 112C, power amplifier 12C, filter 33C, switching circuit 51C, and antenna connection terminal 100C. The receive signal of band B is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 100C, switching circuit 51C, filter 34C, low noise amplifier 22C, and output terminal 122C. The receive signal of band C is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 100C, switching circuit 51C, filter 35C, low noise amplifier 23C, and output terminal 123C. The receive signal of band D is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 100C, switching circuit 51C, filter 36C, low noise amplifier 24C, and output terminal 124C.

[0329] [4.3 Summary]

[0330] As described above, the high-frequency circuit 1C according to this embodiment includes: filters 31C and / or 32C, which have a passband including a frequency band A for TDD; filters 33C and / or 34C, which have a passband including a frequency band B for TDD, wherein the frequency band B and the frequency band A can be transmitted and received simultaneously; filters 41C and / or 42C, which have an attenuation band including the frequency band B; and a switching circuit 51C, which includes a terminal 510C connected to the antenna connection terminal 100C, a terminal 512C and / or 514C connected to the filters 31C and / or 32C, and a terminal 510C connected to the filters 33C and / or 34C. Terminals 516C and / or 518C connected to 4C, and terminals 511C and / or 513C connected to filters 41C and / or 42C; and switching circuits 52C and / or 53C, which include terminals 521C and / or 531C connected to filters 41C and / or 42C, and terminals 522C and / or 532C connected to filters 31C and / or 32C, filters 31C and / or 32C being switchably connected to terminals 511C and / or 513C of switching circuit 51C via switching circuits 52C and / or 53C and filters 41C and / or 42C.

[0331] Therefore, the switching circuit 51C can switch between paths connected to the antenna connection terminal 100C via filters 41C-44C and paths connected to the antenna connection terminal 100C without using filters 41C-44C. Thus, in Simultaneous Rx / Tx, by connecting filters 31C-34C to the antenna connection terminal 100C via filters 41C-44C, interference between the transmitted signal of one frequency band and the received signal of the other frequency band and can be suppressed, thereby improving the quality of the received signal of the other frequency band and frequency band. In particular, it is difficult to sufficiently attenuate the transmitted signal using only the receiving filters (filters 32C or 34C) used in the TDD band; therefore, the improvement in isolation between the transmitted and received paths achieved by filters 42C and 44C is more significant. On the other hand, in addition to Simultaneous Rx / Tx, by connecting filters 31C-34C to antenna connection terminal 100C without passing through switching circuits 52C-55C and filters 41C-44C, signal loss caused by switching circuits 52C-55C and filters 41C-44C can be avoided, and the increase in the required output power of power amplifiers 11C and 12C and the decrease in receiving sensitivity can be suppressed.

[0332] (Modification 1 of Implementation Method 4)

[0333] Next, a variation 1 of embodiment 4 will be described. The main difference between this variation and embodiment 4 is that the transmit filter and receive filter for frequency band A are combined into a single transmit / receive filter, and the transmit filter and receive filter for frequency band B are combined into a single transmit / receive filter. Hereinafter, this variation will be described with reference to the accompanying drawings, focusing on the differences from embodiment 4.

[0334] [5.1 Circuit Structure of High-Frequency Circuit 1D]

[0335] Reference Figure 26 This will illustrate the circuit structure of the high-frequency circuit 1D involved in this variation. Figure 26 This is a circuit diagram of the communication device 5D involved in this variation.

[0336] also, Figure 26 The circuit structures provided are illustrative; the communication device 5D and the high-frequency circuit 1D can be installed using any of a wide variety of circuit mounting and circuit techniques. Therefore, the descriptions of the communication device 5D and the high-frequency circuit 1D provided below should not be interpreted restrictively.

[0337] The communication device 5D involved in this variation is the same as the communication device 5C involved in Embodiment 4, except that it has a high-frequency circuit 1D instead of a high-frequency circuit 1C, so its description is omitted.

[0338] The high-frequency circuit 1D involved in this modification includes power amplifiers 11C and 12C, low-noise amplifiers 21C, 22C, 23C and 24C, filters 31D, 32D, 35C, 36C, 41C and 43C, switching circuits 51D, 52C, 54C, 56D and 57D, antenna connection terminal 100C, input terminals 111C and 112C, and output terminals 121C, 122C, 123C and 124C.

[0339] Filter 31D, an example of the first filter, is a bandpass filter having a passband encompassing the transmit and receive bands of frequency band A. One end of filter 31D is switchably connected to power amplifier 11C and low-noise amplifier 21C. The other end of filter 31D is connected to terminal 512D of switching circuit 51D, and is switchably connected to terminal 511D of switching circuit 51D via switching circuit 52C and filter 41C. Filter 31D is used for both transmission and reception in frequency band A (A-TRx).

[0340] Filter 32D is an example of a second filter, and is a bandpass filter having a passband that includes the transmit and receive bands of frequency band B. One end of filter 32D is switchably connected to power amplifier 12C and low-noise amplifier 22C. On the other hand, the other end of filter 32D is connected to terminal 514D of switching circuit 51D, and is switchably connected to terminal 513D of switching circuit 51C via switching circuit 54C and filter 43C. Filter 32D is used for both transmit and receive in frequency band B (B-TRx).

[0341] Switching circuit 51D is an example of a first switching circuit, including terminals 510D to 515D. Terminal 510D is an example of a first terminal, connected to antenna connection terminal 100C. Terminal 511D is an example of a fourth terminal, connected to filter 41C. Terminal 512D is an example of a second terminal, connected to filter 31D. Terminal 513D is connected to filter 43C. Terminal 514D is an example of a third terminal, connected to filter 32D. Terminal 515D is connected to filters 35C and 36C.

[0342] In such a connection structure, the switching circuit 51D can, for example, connect terminal 510D to terminals 511D to 515D based on a control signal from RFIC 3. The switching circuit 51D is, for example, a multi-connection type switching circuit.

[0343] The switching circuit 56D includes terminals 561D to 563D. Terminal 561D is connected to filter 31D. Terminal 562D is connected to the output of power amplifier 11C. Terminal 563D is connected to the input of low-noise amplifier 21C.

[0344] In such a connection structure, the switching circuit 56D can, for example, connect terminals 561D, 562D, and 563D exclusively based on control signals from RFIC 3. The switching circuit 56D is, for example, constructed from an SPDT-type switching circuit.

[0345] The switching circuit 57D includes terminals 571D to 573D. Terminal 571D is connected to filter 31D. Terminal 572D is connected to the output of power amplifier 12C. Terminal 573D is connected to the input of low-noise amplifier 22C.

[0346] In such a connection structure, the switching circuit 57D can, for example, connect terminals 571D, 572D, and 573D exclusively based on control signals from RFIC 3. The switching circuit 57D is, for example, constructed from an SPDT-type switching circuit.

[0347] [5.2 Communication Mode of Communication Device 5D]

[0348] Next, the communication mode of the communication device 5D will be explained.

[0349] [5.2.1 First Mode]

[0350] First, refer to Figure 27 The first mode will be explained. Figure 27 This is a diagram illustrating a first mode of the communication device 5D involved in this variation.

[0351] In the first mode, signal transmission in frequency band A and signal reception in frequency band B are performed simultaneously. That is, the first mode corresponds to the first connection method in embodiments 1-3 described above, and is a communication mode for Simultaneous Rx / Tx. For example... Figure 27 As shown, in the first mode, switch circuit 51D connects terminal 510D to terminals 511D and 513D, but does not connect terminal 510D to terminals 512D, 514D, and 515D. Furthermore, switch circuit 52C connects terminal 521C to terminal 522C, and switch circuit 54C connects terminal 541C to terminal 542C. That is, switch circuits 52C and 54C are closed. Additionally, switch circuit 56D connects terminal 561D to terminal 562D, but does not connect terminal 561D to terminal 563D. Furthermore, switch circuit 57D connects terminal 571D to terminal 573D, but does not connect terminal 571D to terminal 572D. Therefore, filters 31D and 41C are connected to the transmission path of frequency band A, and filters 32D and 43C are connected to the reception path of frequency band B.

[0352] As a result, the transmit signal for band A is transmitted from RFIC 3 to antenna 2 via input terminal 111C, power amplifier 11C, switching circuit 56D, filter 31D, switching circuit 52C, filter 41C, switching circuit 51D again, and antenna connection terminal 100C. The receive signal for band B is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 100C, switching circuit 51D, filter 43C, switching circuit 54C, filter 32D, switching circuit 57D, low-noise amplifier 22C, and output terminal 122C.

[0353] [5.2.2 Second Mode]

[0354] Next, refer to Figure 28 The second mode will be explained. Figure 28 This is a diagram illustrating a second mode of the communication device 5D involved in this variation.

[0355] In the second mode, signal transmission in frequency band B and signal reception in frequency band A are performed simultaneously. That is, the second mode corresponds to the second connection method in embodiments 1-3 described above, and is a communication mode for Simultaneous Rx / Tx. For example... Figure 28 As shown, in the second mode, switch circuit 51D connects terminal 510D to terminals 511D and 513D, but does not connect terminal 510D to terminals 512D, 514D, and 515D. Furthermore, switch circuit 52C connects terminal 521C to terminal 522C, and switch circuit 54C connects terminal 541C to terminal 542C. That is, switch circuits 52C and 54C are closed. Additionally, switch circuit 56D connects terminal 561D to terminal 563D, but does not connect terminal 561D to terminal 562D. Furthermore, switch circuit 57D connects terminal 571D to terminal 572D, but does not connect terminal 571D to terminal 573D. Thus, filters 31D and 41C are connected to the receiving path of frequency band A, and filters 32D and 43C are connected to the transmitting path of frequency band B.

[0356] As a result, the transmit signal of band B is transmitted from RFIC 3 to antenna 2 via input terminal 112C, power amplifier 12C, switching circuit 57D, filter 32D, switching circuit 54C, filter 43C, switching circuit 51D, and antenna connection terminal 100C. The receive signal of band A is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 100C, switching circuit 51D, filter 41C, switching circuit 52C, filter 31D, switching circuit 56D, low-noise amplifier 21C, and output terminal 121C.

[0357] [5.2.3 Third Mode]

[0358] Next, refer to Figure 29 The third mode will be explained. Figure 29 This is a diagram illustrating the third mode of the communication device 5D involved in this variation.

[0359] In the third mode, the transmission and reception of signals in frequency band A are switched according to time, while signals in frequency bands C and D are received. For example... Figure 29 As shown, in the third mode, switch circuit 51D connects terminal 510D to terminals 512D and 515D, but does not connect terminal 510D to terminals 511D, 513D, and 514D. Switch circuit 56D switches the connection of terminal 561D between terminals 562D and 563D. At this time, switch circuit 52C is disconnected. Therefore, filter 31D is connected to the transmit / receive path of frequency band A, and filters 35C and 36C are connected to the receive paths of frequency bands C and D, respectively.

[0360] As a result, the transmit signal of band A is transmitted from RFIC 3 to antenna 2 via input terminal 111C, power amplifier 11C, switching circuit 56D, filter 31D, switching circuit 51D again, and antenna connection terminal 100C. The receive signal of band A is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 100C, switching circuit 51D, filter 31D, switching circuit 51D again, low noise amplifier 21C, and output terminal 121C. The receive signal of band C is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 100C, switching circuit 51D, filter 35C, low noise amplifier 23C, and output terminal 123C. The receive signal of band D is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 100C, switching circuit 51D, filter 36C, low noise amplifier 24C, and output terminal 124C.

[0361] [5.2.4 Fourth Mode]

[0362] Next, refer to Figure 30 The fourth mode will be explained. Figure 30 This is a diagram illustrating the fourth mode of the communication device 5D involved in this variation.

[0363] In the fourth mode, the transmission and reception of signals in frequency band B are switched according to time, while signals in frequency bands C and D are received. For example... Figure 30 As shown, in the fourth mode, switch circuit 51D connects terminal 510D to terminals 514D and 515D, but does not connect terminal 510D to terminals 511D to 513D. Switch circuit 57D switches the connection of terminal 571D between terminals 572D and 573D. At this time, switch circuit 54C is disconnected. As a result, filter 32D is connected to the transmit / receive path of frequency band B, and filters 35C and 36C are connected to the receive paths of frequency bands C and D, respectively.

[0364] As a result, the transmit signal of band B is transmitted from RFIC 3 to antenna 2 via input terminal 112C, power amplifier 12C, switching circuit 57D, filter 32D, switching circuit 51D, and antenna connection terminal 100C. The receive signal of band B is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 100C, switching circuit 51D, filter 32D, switching circuit 57D, low noise amplifier 22C, and output terminal 122C. The receive signal of band C is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 100C, switching circuit 51D, filter 35C, low noise amplifier 23C, and output terminal 123C. The receive signal of band D is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 100C, switching circuit 51D, filter 36C, low noise amplifier 24C, and output terminal 124C.

[0365] [5.3 Summary]

[0366] As described above, the high-frequency circuit 1D involved in this modification includes: a filter 31D having a passband including a frequency band A for TDD; a filter 32D having a passband including a frequency band B for TDD, wherein the frequency band B and the frequency band A can be transmitted and received simultaneously; a filter 41C having an attenuation band including the frequency band B; a switching circuit 51D including a terminal 510D connected to an antenna connection terminal 100C, a terminal 512D connected to a filter 31D, a terminal 514D connected to a filter 32D, and a terminal 511D connected to a filter 41C; and a switching circuit 52C including a terminal 521C connected to a filter 41C and a terminal 522C connected to a filter 31D, wherein the filter 31D is switchably connected to the terminal 511D of the switching circuit 51D via the switching circuit 52C and the filter 41C.

[0367] Therefore, the same effect as in embodiment 4 above can be achieved, and the number of filters and the number of terminals of the switching circuit 51D can be reduced.

[0368] (Modification 2 of Implementation Method 4)

[0369] Next, a variation 2 of embodiment 4 will be described. The main difference between this variation and embodiment 4 is that the switching circuit for using filter 41C in both the transmitting and receiving sides, and the switching circuit for using filter 43C in both the transmitting and receiving sides, are included in a high-frequency circuit. Hereinafter, this variation will be described with reference to the accompanying drawings, focusing on the differences from embodiment 4.

[0370] [6.1 Circuit Structure of High-Frequency Circuit 1E]

[0371] Reference Figure 31 This will illustrate the circuit structure of the high-frequency circuit 1E involved in this variation. Figure 31 This is a circuit diagram of the communication device 5E involved in this variation.

[0372] also, Figure 31 The circuit structures provided are illustrative; the communication device 5E and the high-frequency circuit 1E can be installed using any of a wide variety of circuit mounting methods and techniques. Therefore, the descriptions of the communication device 5E and the high-frequency circuit 1E provided below should not be interpreted restrictively.

[0373] The communication device 5E involved in this variation is the same as the communication device 5C involved in Embodiment 4, except that it has a high-frequency circuit 1E instead of a high-frequency circuit 1C, so its description is omitted.

[0374] The high-frequency circuit 1E involved in this modification includes power amplifiers 11C and 12C, low-noise amplifiers 21C, 22C, 23C and 24C, filters 31C, 32C, 33C, 34C, 35C, 36C, 41C and 43C, switching circuits 51E, 52E and 53E, antenna connection terminal 100C, input terminals 111C and 112C, and output terminals 121C, 122C, 123C and 124C.

[0375] Switching circuit 51E is an example of a first switching circuit, including terminals 510E to 517E. Terminal 510E is an example of a first terminal, connected to antenna connection terminal 100C. Terminal 511E is an example of a fourth terminal, connected to filter 41C. Terminal 512E is an example of a second terminal, connected to filter 31C. Terminal 513E is an example of a third terminal, connected to filter 32C. Terminal 514E is connected to filter 43C. Terminal 515E is connected to filter 33C. Terminal 516E is connected to filter 34C. Terminal 517E is connected to filters 35C and 36C.

[0376] In such a connection structure, the switching circuit 51E can, for example, connect terminal 510E to terminals 511E to 517E based on a control signal from RFIC 3. The switching circuit 51E is, for example, composed of a multi-connection type switching circuit.

[0377] Switching circuit 52E is an example of a second switching circuit, including terminals 521E to 523E. Terminal 521E is an example of a fifth terminal, connected to filter 41C. Terminal 522E is an example of a sixth terminal, connected to filter 31C. Terminal 523E is an example of a sixth terminal, connected to filter 32C.

[0378] In this connection structure, the switching circuit 52E can, for example, connect terminals 521E, 522E, and 523E exclusively based on control signals from RFIC 3. Specifically, the switching circuit 52E can also connect terminals 521E and 522E in a first mode, or connect terminals 521E and 523E in a second mode. The switching circuit 52E is, for example, constructed from an SPDT-type switching circuit.

[0379] The switching circuit 53E includes terminals 531E to 533E. Terminal 531E is connected to filter 43C. Terminal 532E is connected to filter 33C. Terminal 533E is connected to filter 34C.

[0380] In this connection structure, the switching circuit 53E can, for example, connect terminals 531E, 532E, and 533E exclusively based on control signals from RFIC 3. Specifically, the switching circuit 53E can connect terminals 531E and 533E in a first mode, and also connect terminals 531E and 532E in a second mode. The switching circuit 53E is, for example, constructed from an SPDT-type switching circuit.

[0381] [6.2 Summary]

[0382] As described above, the high-frequency circuit 1E involved in this modification includes: filters 31C and / or 32C, which have a passband including frequency band A for TDD; filters 33C and / or 34C, which have a passband including frequency band B for TDD, wherein frequency band B and frequency band A can be transmitted and received simultaneously; filter 41C, which has an attenuation band including frequency band B; and a switching circuit 51E, which includes a terminal 510E connected to antenna connection terminal 100C and a terminal 510E connected to filters 31C and / or 32C. Terminals 12E and / or 513E, terminals 515E and / or 516E connected to filters 33C and / or 34C, and terminal 511E connected to filter 41C; and a switching circuit 52E, which includes terminals 521E connected to filter 41C and terminals 522E and / or 523E connected to filters 31C and / or 32C, wherein filters 31C and / or 32C are switchably connected to terminals 511E of the switching circuit 51E via the switching circuit 52E and the filter 41C.

[0383] Therefore, the same effect as in embodiment 4 above can be achieved, and the number of filters and the number of terminals of the switching circuit 51E can be reduced.

[0384] (Modification 3 of Implementation Method 4)

[0385] Next, a variation 3 of embodiment 4 will be described. The main difference between this variation and embodiment 4 is that the switching circuit for using filter 41C in both the transmitting and receiving sides, and the switching circuit for using filter 43C in both the transmitting and receiving sides, are included in a high-frequency circuit. Hereinafter, this variation will be described with reference to the accompanying drawings, focusing on the differences from embodiment 4.

[0386] [7.1 Circuit Structure of High-Frequency Circuit 1F]

[0387] Reference Figure 32 To illustrate the circuit structure of the high-frequency circuit 1F involved in this variation. Figure 32 This is a circuit diagram of the communication device 5F involved in this variation.

[0388] also, Figure 32 The circuit structures provided are illustrative; the communication device 5F and the high-frequency circuit 1F can be installed using any of a wide variety of circuit mounting methods and techniques. Therefore, the descriptions of the communication device 5F and the high-frequency circuit 1F provided below should not be interpreted restrictively.

[0389] The communication device 5F involved in this variation is the same as the communication device 5C involved in Embodiment 4, except that it has a high-frequency circuit 1F instead of a high-frequency circuit 1C, so its description is omitted.

[0390] The high-frequency circuit 1F involved in this modification includes power amplifiers 11C and 12C, low-noise amplifiers 21C, 22C, 23C and 24C, filters 31C, 32C, 33C, 34C, 35C, 36C, 41C and 43C, switching circuits 51F, 52F and 53F, antenna connection terminal 100C, input terminals 111C and 112C, and output terminals 121C, 122C, 123C and 124C.

[0391] Switching circuit 51F is an example of a first switching circuit, including terminals 510F to 515F. Terminal 510F is an example of a first terminal, connected to antenna connection terminal 100C. Terminal 511F is an example of a fourth terminal, connected to filter 41C. Terminal 512F is an example of a second terminal, connected to filters 31C and 32C in a switchable manner. Terminal 513F is connected to filter 43C. Terminal 514F is an example of a third terminal, connected to filters 33C and 34C in a switchable manner. Terminal 515F is connected to filters 35C and 36C.

[0392] In such a connection structure, the switching circuit 51F can, for example, connect terminal 510F to terminals 511F to 515F based on control signals from RFIC 3. Specifically, the switching circuit 51F can also connect terminal 510F to terminals 511F and 513F in a first mode and a second mode, connect terminal 510F to terminals 512F and 515F in a third mode, and connect terminal 510F to terminals 514F and 515F in a fourth mode. The switching circuit 51F is, for example, configured as a multi-connection type switching circuit.

[0393] Switching circuit 52F is an example of a second switching circuit, including terminals 521F to 524F. Terminal 521F is an example of a fifth terminal, connected to filter 41C. Terminal 522F is an example of a fifth terminal, connected to terminal 512F of switching circuit 51F. Terminal 523F is an example of a sixth terminal, connected to filter 31C. Terminal 524F is an example of a sixth terminal, connected to filter 32C.

[0394] In this connection structure, the switching circuit 52F can, for example, connect terminals 521F and 522F to terminals 523F and 524F based on control signals from RFIC 3. Specifically, the switching circuit 52F can also connect terminals 521F and 523F in a first mode, connect terminals 521F and 524F in a second mode, and switch the connection of terminal 522F between terminals 523F and 524F in a third mode. The switching circuit 52F is, for example, a DPDT (Double-Pole Double-Throw) type switching circuit.

[0395] The switching circuit 53F includes terminals 531F to 534F. Terminal 531F is connected to filter 43C. Terminal 532F is connected to terminal 514F of the switching circuit 51F. Terminal 533F is connected to filter 33C. Terminal 534F is connected to filter 34C.

[0396] In this connection structure, the switching circuit 53F can, for example, connect terminals 531F and 532F to terminals 533F and 534F based on control signals from RFIC 3. Specifically, the switching circuit 53F can also connect terminals 531F and 534F in a first mode, connect terminals 531F and 533F in a second mode, and switch the connection of terminal 532F between terminals 533F and 534F in a third mode. The switching circuit 53F is, for example, a DPDT-type switching circuit.

[0397] (Implementation Method 5)

[0398] Next, Embodiment 5 will be described. The main difference between this embodiment and Embodiment 4 is that filters 41C to 44C are connected between filters 31C to 34C and power amplifiers 11C and 12C, as well as low-noise amplifiers 21C and 22C. Hereinafter, this embodiment will be described with reference to the accompanying drawings, focusing on the differences from Embodiment 4.

[0399] [8.1 Circuit Structure of 1G High-Frequency Circuits]

[0400] Reference Figure 33 The circuit structure of the high-frequency circuit 1G involved in this embodiment will be explained. Figure 33 This is a circuit diagram of the 5G communication device involved in this embodiment.

[0401] also, Figure 33The circuit structures described below are illustrative. The 5G communication device and the 1G high-frequency circuit can be installed using any of a wide variety of circuit mounting methods and technologies. Therefore, the following descriptions of the 5G communication device and the 1G high-frequency circuit should not be interpreted restrictively.

[0402] The communication device 5G described in this embodiment is the same as the communication device 5C described in Embodiment 4, except that it has a high-frequency circuit 1G instead of a high-frequency circuit 1C, so its description is omitted.

[0403] The high-frequency circuit 1G involved in this embodiment includes power amplifiers 11C and 12C, low-noise amplifiers 21C, 22C, 23C and 24C, filters 31C, 32C, 33C, 34C, 35C, 36C, 41C, 42C, 43C and 44C, switching circuits 51G, 52G, 53G, 54G, 55G, 56G, 57G, 58G and 59G, antenna connection terminal 100C, input terminals 111C and 112C, and output terminals 121C, 122C, 123C and 124C.

[0404] The switching circuit 51G includes terminals 510G to 515G. Terminal 510G is connected to antenna connection terminal 100C. Terminal 511G is connected to filter 31C. Terminal 512G is connected to filter 32C. Terminal 513G is connected to filter 33C. Terminal 514G is connected to filter 34C. Terminal 515G is connected to filters 35C and 36C.

[0405] In such a connection structure, the switching circuit 51G can, for example, connect terminals 510G to terminals 511G to 515G based on control signals from RFIC 3. The switching circuit 51G is, for example, composed of a multi-connection type switching circuit.

[0406] Switching circuit 52G is an example of a second switching circuit, including terminals 521G and 522G. Terminal 521G is an example of a fourth terminal, connected to filter 31C. Terminal 522G is an example of a fifth terminal, connected to filter 41C.

[0407] In such a connection structure, the switching circuit 52G can, for example, connect terminals 521G and 522G based on control signals from RFIC 3. The switching circuit 52G is, for example, constructed from an SPST-type switching circuit.

[0408] Switching circuit 53G is an example of a second switching circuit, including terminals 531G and 532G. Terminal 531G is an example of a fourth terminal, connected to filter 32C. Terminal 532G is an example of a fifth terminal, connected to filter 42C.

[0409] In such a connection structure, the switching circuit 53G can, for example, connect terminal 531G and terminal 532G based on a control signal from RFIC 3. The switching circuit 53G is, for example, constructed from an SPST-type switching circuit.

[0410] The switching circuit 54G includes terminals 541G and 542G. Terminal 541G is connected to filter 33C. Terminal 542G is connected to filter 43C.

[0411] In such a connection structure, the switching circuit 54G can, for example, connect terminals 541G and 542G based on control signals from RFIC 3. The switching circuit 54G is, for example, composed of an SPST type switching circuit.

[0412] The switching circuit 55G includes terminals 551G and 552G. Terminal 551G is connected to filter 34C. Terminal 552G is connected to filter 44C.

[0413] In such a connection structure, the switching circuit 55G can, for example, connect terminals 551G and 552G based on control signals from RFIC 3. The switching circuit 55G is, for example, constructed from an SPST-type switching circuit.

[0414] Switching circuit 56G is an example of the first switching circuit, including terminals 561G to 563G. Terminal 561G is an example of the first terminal, connected to power amplifier 11C. Terminal 562G is an example of the second terminal, connected to filter 31C. Terminal 563G is an example of the third terminal, connected to filter 41C.

[0415] In such a connection structure, the switching circuit 56G can, for example, connect terminals 561G, 562G, and 563G exclusively based on control signals from RFIC 3. The switching circuit 56G is, for example, constructed from an SPDT-type switching circuit.

[0416] Switching circuit 57G is an example of the first switching circuit, including terminals 571G to 573G. Terminal 571G is an example of the first terminal, connected to low-noise amplifier 21C. Terminal 572G is an example of the second terminal, connected to filter 32C. Terminal 573G is an example of the third terminal, connected to filter 42C.

[0417] In such a connection structure, the switching circuit 57G can, for example, connect terminals 571G, 572G, and 573G exclusively based on control signals from RFIC 3. The switching circuit 57G is, for example, constructed from an SPDT-type switching circuit.

[0418] The switching circuit 58G includes terminals 581G to 583G. Terminal 581G is connected to power amplifier 12C. Terminal 582G is connected to filter 33C. Terminal 583G is connected to filter 43C.

[0419] In such a connection structure, the switching circuit 58G can, for example, connect terminals 581G, 582G, and 583G exclusively based on control signals from RFIC 3. The switching circuit 58G is, for example, constructed from an SPDT-type switching circuit.

[0420] The switching circuit 59G includes terminals 591G to 593G. Terminal 591G is connected to the low-noise amplifier 22C. Terminal 592G is connected to the filter 34C. Terminal 593G is connected to the filter 44C.

[0421] In such a connection structure, the switching circuit 59G can, for example, connect terminals 591G, 592G, and 593G exclusively based on control signals from RFIC 3. The switching circuit 59G is, for example, constructed from an SPDT-type switching circuit.

[0422] [8.2 Communication Modes of 5G Communication Devices]

[0423] Next, the communication modes of the 5G communication device will be explained.

[0424] [8.2.1 First Mode]

[0425] First, refer to Figure 34 The first mode will be explained. Figure 34 This is a diagram illustrating the first mode of the 5G communication device according to this embodiment.

[0426] In the first mode, signal transmission in frequency band A and signal reception in frequency band B are performed simultaneously. That is, the first mode corresponds to the first connection method in embodiments 1-3 described above, and is a communication mode for Simultaneous Rx / Tx. For example... Figure 34 As shown, in the first mode, switch circuit 51G connects terminal 510G to terminals 511G and 514G, but does not connect terminal 510G to terminals 512G, 513G, and 515G. Switch circuit 52G connects terminal 521G to terminal 522G, and switch circuit 55G connects terminal 551G to terminal 552G. That is, switch circuits 52G and 55G are closed. At this time, switch circuits 53G and 54G are open. As a result, filters 31C and 41C are connected to the transmission path of frequency band A, and filters 34C and 44C are connected to the reception path of frequency band B.

[0427] As a result, the transmit signal for band A is transmitted from RFIC 3 to antenna 2 via input terminal 111C, power amplifier 11C, switching circuit 56G, filter 41C, switching circuit 52G, filter 31C, switching circuit 51G, and antenna connection terminal 100C. The receive signal for band B is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 100C, switching circuit 51G, filter 34C, switching circuit 55G, filter 44C, switching circuit 59G, low-noise amplifier 22C, and output terminal 122C.

[0428] [8.2.2 Second Mode]

[0429] Next, refer to Figure 35 The second mode will be explained. Figure 35 This is a diagram illustrating a second mode of the 5G communication device involved in this embodiment.

[0430] In the second mode, signal transmission in frequency band B and signal reception in frequency band A are performed simultaneously. That is, the second mode corresponds to the second connection method in embodiments 1-3 described above, and is a communication mode for Simultaneous Rx / Tx. For example... Figure 35 As shown, in the second mode, switch circuit 51G connects terminal 510G to terminals 512G and 513G, but does not connect terminal 510G to terminals 511G, 514G, and 515G. Switch circuit 53G connects terminal 531G to terminal 532G, and switch circuit 54G connects terminal 541G to terminal 542G. That is, switch circuits 53G and 54G are closed. At this time, switch circuits 52G and 55G are open. As a result, filters 32C and 42C are connected to the receiving path of frequency band A, and filters 33C and 43C are connected to the transmitting path of frequency band B.

[0431] As a result, the transmit signal of band B is transmitted from RFIC 3 to antenna 2 via input terminal 112C, power amplifier 12C, switching circuit 58G, filter 43C, switching circuit 54G, filter 33C, switching circuit 51G, and antenna connection terminal 100C. The receive signal of band A is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 100C, switching circuit 51G, filter 32C, switching circuit 53G, filter 42C, switching circuit 57G, low-noise amplifier 21C, and output terminal 121C.

[0432] [8.2.3 Third Mode]

[0433] Next, refer to Figure 36 The third mode will be explained. Figure 36 This is a diagram illustrating the third mode of the 5G communication device involved in this embodiment.

[0434] In the third mode, the transmission and reception of signals in frequency band A are switched according to time, while signals in frequency bands C and D are received. For example... Figure 36 As shown, in the third mode, the switching circuit 51G connects terminal 510G to terminal 515G, and switches the connection of terminal 510G between terminals 511G and 512G. At this time, the switching circuit 51G does not connect terminal 510G to terminals 513G and 514G. Therefore, filter 31C is connected to the transmit path of frequency band A, filter 32C is connected to the receive path of frequency band A, and filters 35C and 36C are connected to the receive paths of frequency bands C and D, respectively.

[0435] As a result, the transmit signal of band A is transmitted from RFIC 3 to antenna 2 via input terminal 111C, power amplifier 11C, switching circuit 56G, filter 31C, switching circuit 51G again, and antenna connection terminal 100C. The receive signal of band A is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 100C, switching circuit 51G, filter 32C, switching circuit 57G, low noise amplifier 21C, and output terminal 121C. The receive signal of band C is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 100C, switching circuit 51G, filter 35C, low noise amplifier 23C, and output terminal 123C. The receive signal of band D is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 100C, switching circuit 51G, filter 36C, low noise amplifier 24C, and output terminal 124C.

[0436] [8.2.4 Fourth Mode]

[0437] Next, refer to Figure 37 The fourth mode will be explained. Figure 37 This is a diagram illustrating the fourth mode of the 5G communication device involved in this embodiment.

[0438] In the fourth mode, the transmission and reception of signals in frequency band B are switched according to time, while signals in frequency bands C and D are received. For example... Figure 37 As shown, in the fourth mode, the switching circuit 51G connects terminal 510G to terminal 515G, and switches the connection of terminal 510G between terminals 513G and 514G. At this time, the switching circuit 51G does not connect terminal 510G to terminals 511G and 512G. Therefore, filter 33C is connected to the transmit path of frequency band B, filter 34C is connected to the receive path of frequency band B, and filters 35C and 36C are connected to the receive paths of frequency bands C and D, respectively.

[0439] As a result, the transmit signal of band B is transmitted from RFIC 3 to antenna 2 via input terminal 112C, power amplifier 12C, filter 33C, switching circuit 51G, and antenna connection terminal 100C. The receive signal of band B is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 100C, switching circuit 51G, filter 34C, low noise amplifier 22C, and output terminal 122C. The receive signal of band C is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 100C, switching circuit 51G, filter 35C, low noise amplifier 23C, and output terminal 123C. The receive signal of band D is transmitted from antenna 2 to RFIC 3 via antenna connection terminal 100C, switching circuit 51G, filter 36C, low noise amplifier 24C, and output terminal 124C.

[0440] [8.3 Summary]

[0441] As described above, the high-frequency circuit 1G according to this embodiment includes: filters 31C and / or 32C, which have a passband including frequency band A for TDD; filters 33C and / or 34C, which have a passband including frequency band B for TDD, wherein frequency band B and frequency band A can be transmitted and received simultaneously; filters 41C and / or 42C, which have an attenuation band including frequency band B; and switching circuits 56G and / or 57G, which include terminals 561G and / or 571G connected to power amplifier 11C and / or low noise amplifier 21C, and terminals connected to filters 31C and / or 32C. Sub-terminals 562G and / or 572G, and terminals 563G and / or 573G connected to filters 41C and / or 42C; and switching circuits 52G and / or 53G, which include terminals 521G and / or 531G connected to filters 31C and / or 32C, and terminals 522G and / or 532G connected to filters 41C and / or 42C, wherein filters 31C and / or 32C are connected in a switchable manner to terminals 563G and / or 573G of switching circuits 56G and / or 57G via switching circuits 52G and / or 53G and filters 41C and / or 42C.

[0442] Therefore, the same effect as the above-described embodiment 4 can be achieved.

[0443] (Implementation Method 6)

[0444] Next, Embodiment 6 will be described. The main difference between this embodiment and Embodiment 4 is that the high-frequency circuit includes only a receiving circuit, excluding a transmitting circuit. Hereinafter, this embodiment will be described with reference to the accompanying drawings, focusing on the differences from Embodiment 4.

[0445] [9.1 Circuit Structure of High-Frequency Circuit 1H]

[0446] Reference Figure 38 The circuit structure of the high-frequency circuit 1H involved in this embodiment will be explained. Figure 38 This is a circuit diagram of the communication device 5H involved in this embodiment.

[0447] also, Figure 38 The circuit structures provided are illustrative; the communication device 5H and the high-frequency circuit 1H can be installed using any of a variety of circuit mounting methods and techniques. Therefore, the descriptions of the communication device 5H and the high-frequency circuit 1H provided below should not be interpreted restrictively.

[0448] The communication device 5H in this embodiment is the same as the communication device 5C in embodiment 4, except that it has a high-frequency circuit 1H instead of a high-frequency circuit 1C, so its description is omitted.

[0449] The high-frequency circuit 1H involved in this embodiment includes low-noise amplifiers 21C, 22C, 23C and 24C, filters 32C, 34C, 35C, 36C, 42C and 44C, switching circuits 51H, 53C and 55C, antenna connection terminal 100C, and output terminals 121C, 122C, 123C and 124C.

[0450] The switching circuit 51H includes terminals 510H to 515H. Terminal 510H is connected to antenna connection terminal 100C. Terminal 511H is connected to filter 42C. Terminal 512H is connected to filter 32C. Terminal 513H is connected to filter 44C. Terminal 514H is connected to filter 34C. Terminal 515H is connected to filters 35C and 36C.

[0451] In such a connection structure, the switching circuit 51H can, for example, connect terminal 510H to terminals 511H to 515H based on a control signal from RFIC 3. The switching circuit 51H is, for example, composed of a multi-connection type switching circuit.

[0452] [9.2 Summary]

[0453] Furthermore, the communication device 5H may also include a transmission circuit (not shown) for frequency bands A and / or B, separate from the high-frequency circuit 1H. In this case, the communication device 5H can implement Simultaneous Rx / Tx using the high-frequency circuit 1H and the transmission circuit. Moreover, in Simultaneous Rx / Tx, by connecting the filter 42C or 44C to the receiving path, interference from the transmitted signal of one of frequency bands A and B to the received signal of the other of frequency bands A and B can be suppressed, thereby improving the quality of the received signal of the other of frequency bands A and B.

[0454] (Implementation Method 7)

[0455] Next, Embodiment 7 will be described. The main difference between this embodiment and Embodiment 4 is that the bandpass filter and the Simultaneous Rx / Tx are included in different high-frequency circuits. Hereinafter, this embodiment will be described with reference to the accompanying drawings, focusing on the differences from Embodiment 4.

[0456] [10.1 Circuit Structure of High-Frequency Circuits 1I and 1J]

[0457] Reference Figure 39 The circuit structures of the high-frequency circuits 1I and 1J involved in this embodiment will be explained. Figure 39 This is a circuit diagram of the communication device 5I involved in this embodiment.

[0458] also, Figure 39 The circuit structures described below are illustrative. The communication device 5I and the high-frequency circuits 1I and 1J can be installed using any of a variety of circuit mounting methods and techniques. Therefore, the descriptions of the communication device 5I and the high-frequency circuits 1I and 1J provided below should not be interpreted restrictively.

[0459] The communication device 5I described in this embodiment is the same as the communication device 5C described in Embodiment 4, except that it has high-frequency circuits 1I and 1J instead of high-frequency circuit 1C, so its description is omitted.

[0460] The high-frequency circuit 1I involved in this embodiment includes power amplifiers 11C and 12C, low-noise amplifiers 21C and 22C, filters 31C, 32C, 33C, 34C, 42C and 44C, switching circuits 51I and 52I, antenna connection terminal 100C, input terminals 111C and 112C, and output terminals 121C, 122C and 131I.

[0461] Output terminal 131I is an external connection terminal of high-frequency circuit 1I, and is a high-frequency output terminal. Output terminal 131I is connected to high-frequency circuit 1J externally to high-frequency circuit 1I, and connected to switching circuit 52I internally to high-frequency circuit 1I. Output terminal 131I can provide received signals of frequency bands A and B to high-frequency circuit 1J.

[0462] Switching circuit 51I includes terminals 510I to 517I. Terminal 510I is connected to antenna connection terminal 100C. Terminal 511I is connected to filter 42C. Terminal 512I is connected to switching circuit 52I without passing through filters 42C and 44C. Terminal 513I is connected to filter 44C. Terminal 514I is connected to filter 31C. Terminal 515I is connected to filter 32C. Terminal 516I is connected to filter 33C. Terminal 517I is connected to filter 34C.

[0463] In such a connection structure, the switching circuit 51I can, for example, connect terminal 510I to terminals 511I to 517I based on a control signal from RFIC 3. Specifically, the switching circuit 51I can also connect terminal 510I to terminals 513I and 514I in a first mode, connect terminal 510I to terminals 511I and 516I in a second mode, switch the connection of terminal 510I between terminals 512I and 514I in a third mode, and switch the connection of terminal 510I between terminals 512I and 516I in a fourth mode. The switching circuit 51I is, for example, configured as a multi-connection type switching circuit.

[0464] Switching circuit 52I includes terminals 521I to 524I. Terminal 521I is connected to output terminal 131I. Terminal 522I is connected to filter 42C. Terminal 523I is connected to switching circuit 51I without passing through filters 42C and 44C. Terminal 524I is connected to filter 44C.

[0465] In such a connection structure, the switching circuit 52I can, for example, connect terminals 521I to terminals 522I-524I in an exclusive manner based on control signals from RFIC 3. Specifically, the switching circuit 52I can also connect terminals 521I and 524I in a first mode, connect terminals 521I and 522I in a second mode, and connect terminals 521I and 523I in a third and fourth mode. The switching circuit 52I is, for example, configured as a multi-connection type switching circuit.

[0466] The high-frequency circuit 1J involved in this embodiment includes low-noise amplifiers 25J and 26J, filters 37J and 38J, a switching circuit 53J, an input terminal 101J, and output terminals 125J and 126J.

[0467] Input terminal 101J is an external connection terminal of high-frequency circuit 1J, and is a high-frequency input terminal. Input terminal 101J is connected to high-frequency circuit 1I externally to high-frequency circuit 1J, and connected to switching circuit 53J internally to high-frequency circuit 1J. Input terminal 101J can receive received signals of frequency bands A and B from high-frequency circuit 1I.

[0468] Output terminals 125J and 126J are external connection terminals of the high-frequency circuit 1J, and are high-frequency output terminals.

[0469] The input terminal of the low-noise amplifier 25J is connected to the filter 37J. The output terminal of the low-noise amplifier 25J is connected to the output terminal 125J. The low-noise amplifier 25J can amplify the received signal in frequency band A that has passed through the filter 37J using power supplied from a power source (not shown). Alternatively, the low-noise amplifier 25J may be partially or entirely excluded from the high-frequency circuit 1J. In this case, the low-noise amplifier 25J may be partially or entirely connected between RFIC 3 and the output terminal 125J, or it may be included within RFIC 3.

[0470] The input terminal of the low-noise amplifier 26J is connected to the filter 38J. The output terminal of the low-noise amplifier 26J is connected to the output terminal 126J. The low-noise amplifier 26J can amplify the received signal in frequency band B that has passed through the filter 38J using power supplied from a power source (not shown). Alternatively, the low-noise amplifier 26J may be partially or entirely excluded from the high-frequency circuit 1J. In this case, the low-noise amplifier 26J may be partially or entirely connected between RFIC 3 and the output terminal 126J, or it may be included within RFIC 3.

[0471] Filter 37J is a bandpass filter having a passband that includes the receiving frequency band of band A. One end of filter 37J is connected to low-noise amplifier 25J. On the other hand, the other end of filter 37J is connected to terminal 532J of switching circuit 53J. Filter 37J is used for receiving band A (A-Rx).

[0472] Filter 38J is a bandpass filter with a passband that includes the receiving frequency band B. One end of filter 38J is connected to low-noise amplifier 26J. The other end of filter 38J is connected to terminal 533J of switching circuit 53J. Filter 38J is used for receiving frequency band B (B-Rx).

[0473] The switching circuit 53J includes terminals 531J to 533J. Terminal 531J is connected to input terminal 101J. Terminal 532J is connected to filter 37J. Terminal 533J is connected to filter 38J.

[0474] In this connection structure, the switching circuit 53J can, for example, connect terminals 531J, 532J, and 533J exclusively based on control signals from RFIC 3. Specifically, the switching circuit 53J can connect terminals 531J and 533J in a first mode, in a second mode, in a third mode, and in a fourth mode. The switching circuit 53J is, for example, constructed from an SPDT-type switching circuit.

[0475] [10.2 Summary]

[0476] According to the communication device 5I involved in this embodiment, the same effect as that of embodiment 4 described above can be achieved.

[0477] (A variation of Implementation Method 7)

[0478] Next, a variation of Embodiment 7 will be described. The main difference between this variation and Embodiment 7 is that it has a path that allows the filters 37J and 38J to be connected to the antenna connection terminal 100C without passing through the switching circuit 52I. Hereinafter, this variation will be described with reference to the accompanying drawings, focusing on the differences from Embodiment 7.

[0479] [11.1 Circuit Structure of 1K and 1L High-Frequency Circuits]

[0480] Reference Figure 40 This will be used to illustrate the circuit structure of the high-frequency circuits 1K and 1L involved in this variation. Figure 40 This is a circuit diagram of the communication device 5K involved in this variation.

[0481] also, Figure 40 The circuit structures described below are illustrative. The communication device 5K and the high-frequency circuits 1K and 1L can be installed using any of a variety of circuit mounting methods and techniques. Therefore, the following descriptions of the communication device 5K and the high-frequency circuits 1K and 1L should not be interpreted restrictively.

[0482] The communication device 5K involved in this variation is the same as the communication device 5C involved in Embodiment 4, except that it has high-frequency circuits 1K and 1L to replace high-frequency circuit 1C, so its description is omitted.

[0483] The high-frequency circuit 1K involved in this modification includes power amplifiers 11C and 12C, low-noise amplifiers 21C and 22C, filters 31C, 32C, 33C, 34C, 42C and 44C, switching circuits 51K and 52I, antenna connection terminal 100C, input terminals 111C and 112C, and output terminals 121C, 122C, 131I and 132K. That is to say, the high-frequency circuit 1K differs from the high-frequency circuit 1I involved in Embodiment 7 above in that it includes a switching circuit 51K instead of a switching circuit 51I, and it also includes an output terminal 132K.

[0484] Output terminal 132K is an external connection terminal of high-frequency circuit 1K and is a high-frequency output terminal. Output terminal 132K is connected to high-frequency circuit 1L externally to high-frequency circuit 1K and to switching circuit 51K internally to high-frequency circuit 1K.

[0485] In addition to terminals 510I to 517I, the switching circuit 51K also includes terminal 518K. Terminal 518K is connected to output terminal 132K.

[0486] In this connection structure, the switching circuit 51K can, for example, connect terminal 510I to terminals 511I to 517I and 518K based on control signals from RFIC 3. Specifically, the switching circuit 51K can connect terminal 510I to terminals 513I and 514I in a first mode, to terminals 511I and 516I in a second mode, switch the connection of terminal 510I between terminals 514I and 518K in a third mode, and switch the connection of terminal 510I between terminals 516I and 518K in a fourth mode. The switching circuit 51K is, for example, a multi-connection type switching circuit.

[0487] The high-frequency circuit 1L involved in this modification includes low-noise amplifiers 25J and 26J, filters 37J and 38J, switching circuit 53L, input terminals 101J and 102L, and output terminals 125J and 126J.

[0488] Input terminal 102L is an external connection terminal of high-frequency circuit 1L, and is a high-frequency input terminal. Input terminal 102L is connected externally to high-frequency circuit 1K and internally to switching circuit 53L. Input terminal 102L can receive signals from frequency bands A and B from high-frequency circuit 1K.

[0489] In addition to terminals 531J to 533J, the switching circuit 53L also includes terminal 534L. Terminal 534L is connected to input terminal 102L.

[0490] In this connection structure, the switching circuit 53L can, for example, connect terminals 531J and 534L to terminals 532J and 533J based on control signals from RFIC 3. Specifically, the switching circuit 53L can connect terminals 531J to terminals 533J in a first mode, to terminals 532J in a second mode, to terminals 534L to terminals 532J in a third mode, and to terminals 533J in a fourth mode. The switching circuit 53L is, for example, constructed from an SPDT-type switching circuit.

[0491] [11.2 Summary]

[0492] According to the communication device 5K involved in this modification, compared with the above-described embodiment 7, it is possible to suppress signal loss caused by the switching circuit 52I in the third and fourth modes.

[0493] (Other implementation methods)

[0494] The above description illustrates a high-frequency circuit according to one embodiment of the present invention, but the high-frequency circuit of the present invention is not limited to the above embodiment. Other embodiments implemented by combining any of the constituent elements in the above embodiments, variations of the above embodiments that can be conceived by those skilled in the art by implementing various modifications to the above embodiments 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.

[0495] 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 figures. For example, an impedance matching circuit may be inserted between the power amplifier and / or low-noise amplifier and the filter. Additionally, for example, an impedance matching circuit may be inserted between the filter and the antenna. The impedance matching circuit can be constructed from, for example, inductors and / or capacitors, but is not particularly limited thereto.

[0496] Alternatively, a filter can be added to the high-frequency circuits described in the above embodiments. The added filter can be connected, for example, to terminal 528 of the switching circuit 52B, or to other terminals.

[0497] Furthermore, the communication device according to each embodiment may also have additional antennas added to antenna 2. In this case, terminals may be added to the switching circuit 53, and the added antenna may be connected to the added terminals of the switching circuit 53. In this case, the added terminals may also be exclusively connected to terminals 532 and 533. Alternatively, terminals may be added to the switching circuits 51C, 51D, 51E, 51F, 51G, 51H, 51I, or 51K, and the added antenna may be connected to the added terminals of the switching circuits 51C, 51D, 51E, 51F, 51G, 51H, 51I, or 51K.

[0498] The features of the high-frequency circuit described below based on the above embodiments are shown below.

[0499] <1>

[0500] A high-frequency circuit, comprising:

[0501] First power amplifier;

[0502] First low-noise amplifier and second low-noise amplifier.

[0503] A first filter, which is switchably connected to the first power amplifier, has a passband that includes a first frequency band for time-division duplexing.

[0504] The second filter is connected to the first power amplifier in a switchable manner and has a passband that includes a second frequency band for time division duplexing, wherein the second frequency band and the first frequency band can transmit and receive simultaneously.

[0505] A third filter, which is connected to the first low-noise amplifier, has a passband that includes the first frequency band;

[0506] A fourth filter, connected to the second low-noise amplifier, has a passband that includes the second frequency band;

[0507] The fifth filter has one end connected to the first filter and the third filter in a switchable manner, and the other end connected to the first input / output terminal. The fifth filter has a passband that includes the first frequency band.

[0508] A sixth filter, one end of which is connected to the second filter and the fourth filter in a switchable manner, and the other end of which is connected to the first input / output terminal, the sixth filter having a passband that includes the second frequency band;

[0509] A first switching circuit includes a first terminal connected to the first power amplifier, a second terminal connected to the first filter, and a third terminal connected to the second filter; and

[0510] The second switching circuit includes a fourth terminal connected to the first filter, a fifth terminal connected to the second filter, a sixth terminal connected to the third filter, a seventh terminal connected to the fourth filter, an eighth terminal connected to the fifth filter, a ninth terminal connected to the sixth filter, and a tenth terminal connected to the second input / output terminal without passing through the fifth and sixth filters.

[0511] <2>

[0512] according to <1> The high-frequency circuit, wherein,

[0513] The high-frequency circuit also includes a third switching circuit, which includes an eleventh terminal connected to the antenna, a twelfth terminal connected to the first input / output terminal, and a thirteenth terminal connected to the second input / output terminal.

[0514] <3>

[0515] according to <2> The high-frequency circuit, wherein,

[0516] When simultaneously transmitting signals in the first frequency band and receiving signals in the second frequency band, the first switching circuit connects the first terminal to the second terminal, the second switching circuit connects the fourth terminal to the eighth terminal and the seventh terminal to the ninth terminal, and the third switching circuit connects the eleventh terminal to the twelfth terminal.

[0517] <4>

[0518] according to <2> or <3> The high-frequency circuit, wherein,

[0519] When simultaneously receiving signals from the first frequency band and transmitting signals from the second frequency band, the first switching circuit connects the first terminal to the third terminal, the second switching circuit connects the fifth terminal to the ninth terminal and the sixth terminal to the eighth terminal, and the third switching circuit connects the eleventh terminal to the twelfth terminal.

[0520] <5>

[0521] according to <2> ~ <4> The high-frequency circuit described in any one of the above, wherein,

[0522] When receiving signals from the first frequency band and the second frequency band simultaneously, the second switching circuit connects the sixth and seventh terminals to the tenth terminal, and the third switching circuit connects the eleventh terminal to the thirteenth terminal.

[0523] <6>

[0524] according to <1> ~ <5> The high-frequency circuit described in any one of the above, wherein,

[0525] The combination of the first frequency band and the second frequency band is either a combination of Band40 for LTE (Long Term Evolution) or n40 for 5GNR (5th Generation New Radio) and Band41 for LTE or n41 for 5GNR, or a combination of Band39 for LTE or n39 for 5GNR and Band41 for LTE or n41 for 5GNR.

[0526] <7>

[0527] according to <2> The high-frequency circuit, wherein,

[0528] The first switching circuit also includes a fourteenth terminal and a fifteenth terminal.

[0529] The high-frequency circuit also features:

[0530] A fourth switching circuit includes a sixteenth terminal connected to the first low-noise amplifier, a seventeenth terminal connected to the fourteenth terminal, and an eighteenth terminal connected to the third filter; and

[0531] The fifth switching circuit includes a nineteenth terminal connected to the second low-noise amplifier, a twentieth terminal connected to the fifteenth terminal, and a twenty-first terminal connected to the fourth filter.

[0532] <8>

[0533] according to <7> The high-frequency circuit, wherein,

[0534] When simultaneously transmitting signals in the first frequency band and receiving signals in the second frequency band, the first switching circuit connects the first terminal to the second terminal, the second switching circuit connects the fourth terminal to the eighth terminal and the seventh terminal to the ninth terminal, the third switching circuit connects the eleventh terminal to the twelfth terminal, and the fifth switching circuit connects the nineteenth terminal to the twenty-first terminal.

[0535] <9>

[0536] according to <7> or <8> The high-frequency circuit, wherein,

[0537] When simultaneously receiving signals from the first frequency band and transmitting signals from the second frequency band, the first switching circuit connects the first terminal to the third terminal, the second switching circuit connects the fifth terminal to the ninth terminal and the sixth terminal to the eighth terminal, the third switching circuit connects the eleventh terminal to the twelfth terminal, and the fourth switching circuit connects the sixteenth terminal to the eighteenth terminal.

[0538] <10>

[0539] according to <7> ~ <9> The high-frequency circuit described in any one of the above, wherein,

[0540] When simultaneously receiving signals from the first frequency band and the second frequency band, the first switching circuit connects the second terminal to the fourteenth terminal and the third terminal to the fifteenth terminal; the second switching circuit connects the fourth and fifth terminals to the tenth terminal; the third switching circuit connects the eleventh terminal to the thirteenth terminal; the fourth switching circuit connects the sixteenth terminal to the seventeenth terminal; and the fifth switching circuit connects the nineteenth terminal to the twentieth terminal.

[0541] <11>

[0542] according to <7> ~ <10> The high-frequency circuit described in any one of the above, wherein,

[0543] The combination of the first frequency band and the second frequency band is a combination of Band 40 for LTE or n40 for 5G NR and Band 41 for LTE or n41 for 5G NR, or a combination of Band 39 for LTE or n39 for 5G NR and Band 41 for LTE or n41 for 5G NR.

[0544] <12>

[0545] according to <7> ~ <10> The high-frequency circuit described in any one of the above, wherein,

[0546] The high-frequency circuit also features:

[0547] Second power amplifier;

[0548] Third low-noise amplifier;

[0549] The seventh filter, which is connected to the second power amplifier, has a passband that includes the transmission band of the third frequency band;

[0550] An eighth filter, connected to the third low-noise amplifier, has a passband that includes the receiving band of the third frequency band; and

[0551] The ninth filter has one end connected to the seventh and eighth filters in a switchable manner, and the other end connected to the first input / output terminal. The ninth filter has a passband that includes the transmit band and the receive band of the third frequency band.

[0552] The second switching circuit also includes a twenty-second terminal connected to the seventh filter and the eighth filter, and a twenty-third terminal connected to the ninth filter.

[0553] <13>

[0554] according to <12> The high-frequency circuit, wherein,

[0555] When simultaneously transmitting signals in the first frequency band, receiving signals in the second frequency band, and transmitting and receiving signals in the third frequency band, the first switching circuit connects the first terminal to the second terminal, the second switching circuit connects the fourth terminal to the eighth terminal, the seventh terminal to the ninth terminal, and the twenty-second terminal to the twenty-third terminal, the third switching circuit connects the eleventh terminal to the twelfth terminal, and the fifth switching circuit connects the nineteenth terminal to the twenty-first terminal.

[0556] <14>

[0557] according to <12> or <13> The high-frequency circuit, wherein,

[0558] When simultaneously receiving signals in the first frequency band, transmitting signals in the second frequency band, and transmitting and receiving signals in the third frequency band, the first switching circuit connects the first terminal to the third terminal, the second switching circuit connects the fifth terminal to the ninth terminal, the sixth terminal to the eighth terminal, the twenty-second terminal to the twenty-third terminal, the third switching circuit connects the eleventh terminal to the twelfth terminal, and the fourth switching circuit connects the sixteenth terminal to the eighteenth terminal.

[0559] <15>

[0560] according to <12> ~ <14> The high-frequency circuit described in any one of the above, wherein,

[0561] When simultaneously receiving signals from the first frequency band, receiving signals from the second frequency band, and transmitting and receiving signals from the third frequency band, the first switching circuit connects the second terminal to the fourteenth terminal and the third terminal to the fifteenth terminal; the second switching circuit connects the fourth terminal, the fifth terminal, and the twenty-second terminal to the tenth terminal; the third switching circuit connects the eleventh terminal to the thirteenth terminal; the fourth switching circuit connects the sixteenth terminal to the seventeenth terminal; and the fifth switching circuit connects the nineteenth terminal to the twentyth terminal.

[0562] <16>

[0563] according to <12> ~ <15> The high-frequency circuit described in any one of the above, wherein,

[0564] The combination of the first frequency band and the second frequency band is either a combination of Band 40 for LTE or n40 for 5G NR and Band 41 for LTE or n41 for 5G NR, or a combination of Band 39 for LTE or n39 for 5G NR and Band 41 for LTE or n41 for 5G NR.

[0565] The third frequency band is Band1, Band3, Band5, Band8 or Band28 for LTE, or n1, n3, n5, n8 or n28 for 5G NR.

[0566] <17>

[0567] according to <7> ~ <16> The high-frequency circuit described in any one of the above, wherein,

[0568] At least one of the fifth filter and the sixth filter is an elastic wave filter that includes an inductor, a capacitor, and an elastic wave resonator.

[0569] <18>

[0570] according to <7> ~ <17> The high-frequency circuit described in any one of the above, wherein,

[0571] At least one of the third filter and the fourth filter is an LC filter.

[0572] <19>

[0573] A high-frequency circuit, comprising:

[0574] The first filter has a passband that includes a first frequency band for time-division duplexing;

[0575] The second filter has a passband that includes a second frequency band for time division duplexing, wherein the second frequency band and the first frequency band can transmit and receive simultaneously.

[0576] The third filter has an attenuation band that includes the second frequency band;

[0577] A first switching circuit includes a first terminal connected to an antenna connection terminal, a second terminal connected to the first filter, a third terminal connected to the second filter, and a fourth terminal connected to the third filter; and

[0578] The second switching circuit includes a fifth terminal connected to the third filter and a sixth terminal connected to the first filter.

[0579] The first filter is connected to the fourth terminal of the first switching circuit in a switchable manner via the second switching circuit and the third filter.

[0580] <20>

[0581] A high-frequency circuit, comprising:

[0582] The first filter has a passband that includes a first frequency band for time-division duplexing;

[0583] The second filter has a passband that includes a second frequency band for time division duplexing, wherein the second frequency band and the first frequency band can transmit and receive simultaneously.

[0584] The third filter has an attenuation band that includes the second frequency band;

[0585] A first switching circuit includes a first terminal connected to a power amplifier or a low-noise amplifier, a second terminal connected to the first filter, and a third terminal connected to the third filter; and

[0586] The second switching circuit includes a fourth terminal connected to the first filter and a fifth terminal connected to the third filter.

[0587] The first filter is connected to the third terminal of the first switching circuit in a switchable manner via the second switching circuit and the third filter.

[0588] Industrial availability

[0589] As a high-frequency circuit configured in the front end, this invention can be widely used in communication devices such as portable telephones.

[0590] Explanation of reference numerals in the attached figures

[0591] 1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L: High-frequency circuits;

[0592] 2: Antenna;

[0593] 3: RFIC;

[0594] 4: BBIC;

[0595] 5, 5A, 5B, 5C, 5D, 5E, 5F, 5G, 5H, 5I, 5K: Communication devices;

[0596] 11, 11C, 12B, 12C: Power amplifiers;

[0597] 21, 21C, 22, 22C, 23B, 23C, 24C, 25J, 26J: Low-noise amplifiers;

[0598] 31, 31A, 31C, 31D, 32, 32A, 32C, 32D, 33, 33A, 33C, 34, 34A, 34C, 35, 35A, 35C, 36, 36A, 36C, 37B, 37J, 38B, 38J, 39B, 41C, 42C, 43C, 44C: Filters;

[0599] 51, 51A, 51C, 51D, 51E, 51F, 51G, 51H, 51I, 51K, 52, 52B, 52C, 52E, 52F, 52G, 52I, 53, 53C, 53E, 53F, 53G, 53J, 53L, 54A, 54C, 54G, 55A, 55C, 55G, 56D, 56G, 57D, 57G, 58G, 59G: Switching circuits;

[0600] 100C: Antenna connection terminal;

[0601] 101, 102: Input / output terminals;

[0602] Input terminals 101J, 102L, 111, 111C, 112B, and 112C

[0603] 121, 121C, 122, 122C, 123B, 123C, 124C, 125J, 126J, 131I, 132K: Output terminals.

Claims

1. A high-frequency circuit, comprising: First power amplifier; First low-noise amplifier and second low-noise amplifier. A first filter, which is switchably connected to the first power amplifier, has a passband that includes a first frequency band for time-division duplexing. The second filter, which is switchably connected to the first power amplifier, has a passband that includes a second frequency band for time-division duplexing, wherein... The second frequency band and the first frequency band can transmit and receive simultaneously; A third filter, which is connected to the first low-noise amplifier, has a passband that includes the first frequency band; A fourth filter, connected to the second low-noise amplifier, has a passband that includes the second frequency band; The fifth filter has one end connected to the first filter and the third filter in a switchable manner, and the other end connected to the first input / output terminal. The fifth filter has a passband that includes the first frequency band. A sixth filter, one end of which is connected to the second filter and the fourth filter in a switchable manner, and the other end of which is connected to the first input / output terminal, the sixth filter having a passband that includes the second frequency band; The first switching circuit includes a first terminal connected to the first power amplifier, a second terminal connected to the first filter, and a third terminal connected to the second filter. as well as The second switching circuit includes a fourth terminal connected to the first filter, a fifth terminal connected to the second filter, a sixth terminal connected to the third filter, a seventh terminal connected to the fourth filter, an eighth terminal connected to the fifth filter, a ninth terminal connected to the sixth filter, and a tenth terminal connected to the second input / output terminal without passing through the fifth and sixth filters.

2. The high-frequency circuit according to claim 1, wherein, The high-frequency circuit also includes a third switching circuit, which includes an eleventh terminal connected to the antenna, a twelfth terminal connected to the first input / output terminal, and a thirteenth terminal connected to the second input / output terminal.

3. The high-frequency circuit according to claim 2, wherein, When simultaneously transmitting signals in the first frequency band and receiving signals in the second frequency band, the first switching circuit connects the first terminal to the second terminal, the second switching circuit connects the fourth terminal to the eighth terminal and the seventh terminal to the ninth terminal, and the third switching circuit connects the eleventh terminal to the twelfth terminal.

4. The high-frequency circuit according to claim 2 or 3, wherein, When simultaneously receiving signals from the first frequency band and transmitting signals from the second frequency band, the first switching circuit connects the first terminal to the third terminal, the second switching circuit connects the fifth terminal to the ninth terminal and the sixth terminal to the eighth terminal, and the third switching circuit connects the eleventh terminal to the twelfth terminal.

5. The high-frequency circuit according to any one of claims 2 to 4, wherein, When receiving signals from the first frequency band and the second frequency band simultaneously, the second switching circuit connects the sixth and seventh terminals to the tenth terminal, and the third switching circuit connects the eleventh terminal to the thirteenth terminal.

6. The high-frequency circuit according to any one of claims 1 to 5, wherein, The combination of the first frequency band and the second frequency band is a combination of Band 40 for Long Term Evolution (LTE) or n40 for Fifth Generation New Radio (5GNR) and Band 41 for LTE or n41 for 5GNR, or a combination of Band 39 for LTE or n39 for 5GNR and Band 41 for LTE or n41 for 5GNR.

7. The high-frequency circuit according to claim 2, wherein, The first switching circuit also includes a fourteenth terminal and a fifteenth terminal. The high-frequency circuit also features: The fourth switching circuit includes a sixteenth terminal connected to the first low-noise amplifier, a seventeenth terminal connected to the fourteenth terminal, and an eighteenth terminal connected to the third filter; as well as The fifth switching circuit includes a nineteenth terminal connected to the second low-noise amplifier, a twentieth terminal connected to the fifteenth terminal, and a twenty-first terminal connected to the fourth filter.

8. The high-frequency circuit according to claim 7, wherein, When simultaneously transmitting signals in the first frequency band and receiving signals in the second frequency band, the first switching circuit connects the first terminal to the second terminal, the second switching circuit connects the fourth terminal to the eighth terminal and the seventh terminal to the ninth terminal, the third switching circuit connects the eleventh terminal to the twelfth terminal, and the fifth switching circuit connects the nineteenth terminal to the twenty-first terminal.

9. The high-frequency circuit according to claim 7 or 8, wherein, When simultaneously receiving signals from the first frequency band and transmitting signals from the second frequency band, the first switching circuit connects the first terminal to the third terminal, the second switching circuit connects the fifth terminal to the ninth terminal and the sixth terminal to the eighth terminal, the third switching circuit connects the eleventh terminal to the twelfth terminal, and the fourth switching circuit connects the sixteenth terminal to the eighteenth terminal.

10. The high-frequency circuit according to any one of claims 7 to 9, wherein, When simultaneously receiving signals from the first frequency band and the second frequency band, the first switching circuit connects the second terminal to the fourteenth terminal and the third terminal to the fifteenth terminal; the second switching circuit connects the fourth and fifth terminals to the tenth terminal; the third switching circuit connects the eleventh terminal to the thirteenth terminal; the fourth switching circuit connects the sixteenth terminal to the seventeenth terminal; and the fifth switching circuit connects the nineteenth terminal to the twentieth terminal.

11. The high-frequency circuit according to any one of claims 7 to 10, wherein, The combination of the first frequency band and the second frequency band is a combination of Band 40 for LTE or n40 for 5G NR and Band 41 for LTE or n41 for 5G NR, or a combination of Band 39 for LTE or n39 for 5G NR and Band 41 for LTE or n41 for 5G NR.

12. The high-frequency circuit according to any one of claims 7 to 10, wherein, The high-frequency circuit also features: Second power amplifier; Third low-noise amplifier; The seventh filter, which is connected to the second power amplifier, has a passband that includes the transmission band of the third frequency band; The eighth filter, which is connected to the third low-noise amplifier, has a passband that includes the receiving frequency band of the third frequency band; as well as The ninth filter has one end connected to the seventh and eighth filters in a switchable manner, and the other end connected to the first input / output terminal. The ninth filter has a passband that includes the transmit band and the receive band of the third frequency band. The second switching circuit also includes a twenty-second terminal connected to the seventh filter and the eighth filter, and a twenty-third terminal connected to the ninth filter.

13. The high-frequency circuit according to claim 12, wherein, When simultaneously transmitting signals in the first frequency band, receiving signals in the second frequency band, and transmitting and receiving signals in the third frequency band, the first switching circuit connects the first terminal to the second terminal, the second switching circuit connects the fourth terminal to the eighth terminal, the seventh terminal to the ninth terminal, and the twenty-second terminal to the twenty-third terminal, the third switching circuit connects the eleventh terminal to the twelfth terminal, and the fifth switching circuit connects the nineteenth terminal to the twenty-first terminal.

14. The high-frequency circuit according to claim 12 or 13, wherein, When simultaneously receiving signals in the first frequency band, transmitting signals in the second frequency band, and transmitting and receiving signals in the third frequency band, the first switching circuit connects the first terminal to the third terminal, the second switching circuit connects the fifth terminal to the ninth terminal, the sixth terminal to the eighth terminal, the twenty-second terminal to the twenty-third terminal, the third switching circuit connects the eleventh terminal to the twelfth terminal, and the fourth switching circuit connects the sixteenth terminal to the eighteenth terminal.

15. The high-frequency circuit according to any one of claims 12 to 14, wherein, When simultaneously receiving signals from the first frequency band, receiving signals from the second frequency band, and transmitting and receiving signals from the third frequency band, the first switching circuit connects the second terminal to the fourteenth terminal and the third terminal to the fifteenth terminal; the second switching circuit connects the fourth terminal, the fifth terminal, and the twenty-second terminal to the tenth terminal; the third switching circuit connects the eleventh terminal to the thirteenth terminal; the fourth switching circuit connects the sixteenth terminal to the seventeenth terminal; and the fifth switching circuit connects the nineteenth terminal to the twentyth terminal.

16. The high-frequency circuit according to any one of claims 12 to 15, wherein, The combination of the first frequency band and the second frequency band is either a combination of Band 40 for LTE or n40 for 5G NR and Band 41 for LTE or n41 for 5G NR, or a combination of Band 39 for LTE or n39 for 5G NR and Band 41 for LTE or n41 for 5G NR. The third frequency band is Band1, Band3, Band5, Band8 or Band28 for LTE, or n1, n3, n5, n8 or n28 for 5G NR.

17. The high-frequency circuit according to any one of claims 7 to 16, wherein, At least one of the fifth filter and the sixth filter is an elastic wave filter that includes an inductor, a capacitor, and an elastic wave resonator.

18. The high-frequency circuit according to any one of claims 7 to 17, wherein, At least one of the third filter and the fourth filter is an LC filter.

19. A high-frequency circuit, comprising: The first filter has a passband that includes a first frequency band for time-division duplexing; The second filter has a passband that includes a second frequency band for time-division duplexing, wherein... The second frequency band and the first frequency band can transmit and receive simultaneously; The third filter has an attenuation band that includes the second frequency band; The first switching circuit includes a first terminal connected to the antenna connection terminal, a second terminal connected to the first filter, a third terminal connected to the second filter, and a fourth terminal connected to the third filter. as well as The second switching circuit includes a fifth terminal connected to the third filter and a sixth terminal connected to the first filter. The first filter is connected to the fourth terminal of the first switching circuit in a switchable manner via the second switching circuit and the third filter.

20. A high-frequency circuit, comprising: The first filter has a passband that includes a first frequency band for time-division duplexing; The second filter has a passband that includes a second frequency band for time-division duplexing, wherein... The second frequency band and the first frequency band can transmit and receive simultaneously; The third filter has an attenuation band that includes the second frequency band; The first switching circuit includes a first terminal connected to a power amplifier or a low-noise amplifier, a second terminal connected to the first filter, and a third terminal connected to the third filter. as well as The second switching circuit includes a fourth terminal connected to the first filter and a fifth terminal connected to the third filter. The first filter is connected to the third terminal of the first switching circuit in a switchable manner via the second switching circuit and the third filter.

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