High-frequency module and communication device

Abstract

Provided are a high-frequency module and a communication device capable of reducing transmission loss degradation while enabling communication for a co-banded communication band. A high-frequency module (1) comprises a first filter (21), a second filter (22), and a switch (5). The first filter (21) has a first passband. The first passband includes a reception band of a first communication band. The second filter (22) has a second passband. The second passband includes a transmission band of the first communication band and a reception band of a second communication band. The switch (5) connects the first filter (21) and / or the second filter (22) to an antenna terminal (71). The reception band of the second communication band includes a first band and a second band. The first band is a band overlapping the reception band of the first communication band. The second band is a band overlapping the transmission band of the first communication band. The second filter (22) is a variable filter.

Description

High-frequency module and communication device

[0001] The present invention generally relates to a high-frequency module and a communication device, and more particularly to a high-frequency module including a plurality of filters and a communication device including the high-frequency module.

[0002] As a conventional high-frequency module, Patent Document 1 discloses a front-end circuit in which a variable filter connected to a B13 reception / B28 transmission path and a B13 transmission / B28 reception path can be switched by a plurality of switches according to a communication band.

[0003] Japanese Patent Application Laid-Open No. 2017-168932

[0004] However, in a conventional high-frequency module such as the front-end module (front-end circuit) described in Patent Document 1, there is a problem that it is difficult to suppress deterioration of transmission loss while enabling communication in a Co-Band communication band.

[0005] The present invention has been made in view of the above points, and an object thereof is to provide a high-frequency module and a communication device that can reduce transmission loss deterioration while enabling communication in a Co-Band communication band.

[0006] The high-frequency module according to one aspect of the present invention includes a first filter, a second filter, an antenna terminal, and a switch. The first filter has a first passband. The first passband includes a reception band of a first communication band. The second filter has a second passband. The second passband includes a transmission band of the first communication band and a reception band of a second communication band. The antenna terminal is connected to an antenna. The switch connects at least one of the first filter and the second filter to the antenna terminal. The reception band of the second communication band includes a first band and a second band. The first band overlaps with the reception band of the first communication band. The second band overlaps with the transmission band of the first communication band. The second filter is a variable filter.

[0007] A communication device according to one aspect of the present invention comprises the high-frequency module and a signal processing circuit. The signal processing circuit is connected to the high-frequency module.

[0008] According to the above-described embodiment of the present invention, the high-frequency module and communication device make it possible to reduce transmission loss degradation while enabling communication over co-band communication bands.

[0009] Figure 1 is a schematic diagram of a high-frequency module and communication device according to Embodiment 1. Figure 2 is a circuit diagram of the second filter in the same high-frequency module. Figure 3 is an explanatory diagram for explaining the passbands of the first filter, second filter, and third filter in the same high-frequency module. Figure 4 is a graph showing the frequency characteristics of the second filter in the same high-frequency module. Figure 5 is a schematic diagram of a high-frequency module and communication device according to Embodiment 2. Figure 6 is a circuit diagram of the second filter in the same high-frequency module. Figure 7 is a circuit diagram of the third filter in the same high-frequency module. Figure 8 is an explanatory diagram for explaining the passbands of the first filter, second filter, and third filter in the same high-frequency module. Figure 9 is an explanatory diagram for explaining the operation of the same high-frequency module. Figure 10 is an explanatory diagram for explaining the operation of the same high-frequency module. Figure 11 is a graph showing the frequency characteristics of the third filter in the same high-frequency module.

[0010] The high-frequency module 1 and communication device 9 according to Embodiments 1 and 2 will be described below with reference to the drawings.

[0011] (Embodiment 1) (1) High-frequency module The configuration of the high-frequency module 1 according to Embodiment 1 will be described with reference to the drawings.

[0012] As shown in Figure 1, the high-frequency module 1 according to Embodiment 1 includes a first filter 21, a second filter 22, an antenna terminal 71, and a switch 5. The first filter 21 has a first passband. The first passband includes the receiving band of the first communication band. The second filter 22 has a second passband. The second passband includes the transmitting band of the first communication band and the receiving band of the second communication band. The antenna terminal 71 is a terminal connected to the antenna 91. The switch 5 connects at least one of the first filter 21 and the second filter 22 to the antenna terminal 71. The receiving band of the second communication band includes a first band and a second band. The first band is a band that overlaps with the receiving band of the first communication band. The second band is a band that overlaps with the transmitting band of the first communication band. The second filter 22 is a variable filter.

[0013] According to the high-frequency module 1 of Embodiment 1, communication is possible over co-band communication bands, and the degradation of transmission loss can be reduced.

[0014] As shown in Figure 1, the high-frequency module 1 is used, for example, in a communication device 9. The communication device 9 is, for example, a mobile phone such as a smartphone. However, the communication device 9 is not limited to a mobile phone, and may be a wearable device such as a smartwatch. The high-frequency module 1 is a module that supports, for example, 4G (fourth-generation mobile communication) standards, 5G (fifth-generation mobile communication) standards, etc. The 4G standard is, for example, the 3GPP LTE standard (LTE: Long Term Evolution). The 5G standard is, for example, 5G NR (New Radio). The high-frequency module 1 is a module that supports carrier aggregation and dual connectivity, which simultaneously transmit and receive signals in multiple frequency bands.

[0015] The high-frequency module 1 performs communication across multiple communication bands. More specifically, the high-frequency module 1 transmits transmission signals for each of the multiple communication bands and receives reception signals for each of the multiple communication bands. Specifically, the high-frequency module 1 performs communication on the first communication band, the second communication band, and the third communication band. More specifically, the high-frequency module 1 transmits transmission signals for the first communication band and receives reception signals for the first communication band. Furthermore, the high-frequency module 1 transmits transmission signals for the second communication band and receives reception signals for the second communication band. In addition, the high-frequency module 1 transmits transmission signals for the third communication band and receives reception signals for the third communication band.

[0016] The high-frequency module 1 has multiple transmission paths (three in the example in Figure 1) for transmitting transmission signals for multiple communication bands (first transmission path T1, second transmission path T2, third transmission path T3). The first transmission signal for the first communication band passes through the first transmission path T1, the second transmission signal for the second communication band passes through the second transmission path T2, and the third transmission signal for the third communication band passes through the third transmission path T3.

[0017] The high-frequency module 1 has multiple (three in the example in Figure 1) receiving paths (first receiving path R1, second receiving path R2, third receiving path R3) for receiving signals from multiple communication bands. The first received signal from the first communication band passes through the first receiving path R1, the second received signal from the second communication band passes through the second receiving path R2, and the third received signal from the third communication band passes through the third receiving path R3.

[0018] The transmitted and received signals for each communication band are, for example, FDD (Frequency Division Duplex) signals. FDD is a wireless communication technology that assigns different frequency bands to transmission and reception in wireless communication.

[0019] (2) Components of the High-Frequency Module Hereinafter, each component of the high-frequency module 1 according to Embodiment 1 will be described with reference to the drawings.

[0020] As shown in Figure 1, the high-frequency module 1 according to Embodiment 1 includes a first filter 21, a second filter 22, a third filter 23, a fourth filter 24, a fifth filter 25, a first power amplifier 31, a second power amplifier 32, a third power amplifier 33, a first low-noise amplifier 41, a second low-noise amplifier 42, a third low-noise amplifier 43, a switch 5, and a plurality of (seven in the example of Figure 1) external connection terminals 7.

[0021] (2.1) External Connection Terminals The multiple external connection terminals 7, as shown in Figure 1, include an antenna terminal 71, multiple (three in the example of Figure 1) input terminals 72 to 74, and multiple (three in the example of Figure 1) output terminals 75 to 77. The antenna terminal 71 is connected to the antenna 91, which will be described later. The multiple input terminals 72 to 74 and the multiple output terminals 75 to 77 are connected to the signal processing circuit 92, which will be described later. The multiple input terminals 72 to 74 are terminals to which high-frequency signals (transmit signals) from the signal processing circuit 92 are input to the high-frequency module 1. The multiple output terminals 75 to 77 are terminals to which high-frequency signals (received signals) from multiple low-noise amplifiers (first low-noise amplifier 41, second low-noise amplifier 42, third low-noise amplifier 43) are output to the signal processing circuit 92.

[0022] (2.2) First Power Amplifier The first power amplifier 31 shown in Figure 1 amplifies the amplitude of the first transmission signal in the first communication band. The first transmission signal amplified by the first power amplifier 31 is output to the second filter 22.

[0023] The first power amplifier 31 is located between the input terminal 72 and the second filter 22 in the first transmission path T1 connecting the input terminal 72 and the antenna terminal 71. More specifically, the input terminal of the first power amplifier 31 is connected to the input terminal 72, and the output terminal of the first power amplifier 31 is connected to the second filter 22. The first power amplifier 31 is connected to an external circuit (for example, a signal processing circuit 92) via the input terminal 72. The first power amplifier 31 is also connected to the switch 5 via the second filter 22.

[0024] (2.3) Second Power Amplifier The second power amplifier 32 shown in Figure 1 amplifies the amplitude of the second transmission signal in the second communication band. The second transmission signal amplified by the second power amplifier 32 is output to the third filter 23.

[0025] The second power amplifier 32 is located between the input terminal 73 and the third filter 23 in the second transmission path T2 connecting the input terminal 73 and the antenna terminal 71. More specifically, the input terminal of the second power amplifier 32 is connected to the input terminal 73, and the output terminal of the second power amplifier 32 is connected to the third filter 23. The second power amplifier 32 is connected to an external circuit (for example, a signal processing circuit 92) via the input terminal 73. The second power amplifier 32 is also connected to the switch 5 via the third filter 23.

[0026] (2.4) Third Power Amplifier The third power amplifier 33 shown in Figure 1 amplifies the amplitude of the third transmission signal in the third communication band. The third transmission signal amplified by the third power amplifier 33 is output to the fourth filter 24.

[0027] The third power amplifier 33 is located between the input terminal 74 and the fourth filter 24 in the third transmission path T3 connecting the input terminal 74 and the antenna terminal 71. More specifically, the input terminal of the third power amplifier 33 is connected to the input terminal 74, and the output terminal of the third power amplifier 33 is connected to the fourth filter 24. The third power amplifier 33 is connected to an external circuit (for example, a signal processing circuit 92) via the input terminal 74. The third power amplifier 33 is also connected to the switch 5 via the fourth filter 24.

[0028] (2.5) First Low-Noise Amplifier The first low-noise amplifier 41 shown in Figure 1 amplifies the amplitude of the first received signal in the first communication band with low noise. The first received signal amplified by the first low-noise amplifier 41 is output to the output terminal 75.

[0029] The first low-noise amplifier 41 is located between the first filter 21 and the output terminal 75 in the first receiving path R1 connecting the antenna terminal 71 and the output terminal 75. More specifically, the input terminal of the first low-noise amplifier 41 is connected to the first filter 21, and the output terminal of the first low-noise amplifier 41 is connected to the output terminal 75. The first low-noise amplifier 41 is connected to the switch 5 via the first filter 21. The first low-noise amplifier 41 is also connected to an external circuit (for example, a signal processing circuit 92) via the output terminal 75.

[0030] (2.6) Second Low-Noise Amplifier The second low-noise amplifier 42 shown in Figure 1 amplifies the amplitude of the second received signal in the second communication band with low noise. The second received signal amplified by the second low-noise amplifier 42 is output to the output terminal 76.

[0031] The second low-noise amplifier 42 is located between the second filter 22 and the output terminal 76 in the second receiving path R2 connecting the antenna terminal 71 and the output terminal 76. More specifically, the input terminal of the second low-noise amplifier 42 is connected to the second filter 22, and the output terminal of the second low-noise amplifier 42 is connected to the output terminal 76. The second low-noise amplifier 42 is connected to the switch 5 via the second filter 22. The second low-noise amplifier 42 is also connected to an external circuit (for example, a signal processing circuit 92) via the output terminal 76.

[0032] (2.7) Third Low-Noise Amplifier The third low-noise amplifier 43 shown in Figure 1 amplifies the amplitude of the third received signal in the third communication band with low noise. The third received signal amplified by the third low-noise amplifier 43 is output to the output terminal 77.

[0033] The third low-noise amplifier 43 is located between the fifth filter 25 and the output terminal 77 in the third receiving path R3 connecting the antenna terminal 71 and the output terminal 77. More specifically, the input terminal of the third low-noise amplifier 43 is connected to the fifth filter 25, and the output terminal of the third low-noise amplifier 43 is connected to the output terminal 77. The third low-noise amplifier 43 is connected to the switch 5 via the fifth filter 25. The third low-noise amplifier 43 is also connected to an external circuit (for example, a signal processing circuit 92) via the output terminal 77.

[0034] (2.8) First Filter The first filter 21 shown in Figure 1 is a filter having a first passband. The first passband includes the receiving band of the first communication band. The first filter 21 is a receiving filter that allows the first received signal of the first communication band to pass through. The first filter 21 is a variable filter, as shown in Figure 1.

[0035] The first filter 21 is provided between the antenna terminal 71 and the first low-noise amplifier 41 in the first receiving path R1 that connects the antenna terminal 71 and the output terminal 75. More specifically, the first filter 21 is connected to the switch 5 and the first low-noise amplifier 41 in the first receiving path R1. The first filter 21 allows the first received signal of the first communication band to pass through from the high-frequency signal input from the antenna terminal 71.

[0036] (2.9) Second Filter The second filter 22 shown in Figure 1 is a filter having a second passband. The second passband includes the transmission band of the first communication band and the reception band of the second communication band. The second filter 22 is a transmit / receive filter that allows the first transmit signal of the first communication band to pass through and the second receive signal of the second communication band to pass through.

[0037] The second filter 22 is located between the first power amplifier 31 and the antenna terminal 71 in the first transmission path T1 that connects the input terminal 72 and the antenna terminal 71. More specifically, the second filter 22 is connected to the first power amplifier 31 and the switch 5 in the first transmission path T1. The second filter 22 allows the first transmission signal of the first communication band to pass through from the high-frequency signals input from the external circuit.

[0038] The second filter 22 is located between the antenna terminal 71 and the second low-noise amplifier 42 in the second receiving path R2 that connects the antenna terminal 71 and the output terminal 76. More specifically, the second filter 22 is connected between the switch 5 and the second low-noise amplifier 42 in the second receiving path R2. The second filter 22 allows the second received signal of the second communication band to pass through from the high-frequency signal input from the antenna terminal 71.

[0039] As shown in Figure 1, the second filter 22 is a variable filter. The second filter 22 is configured to allow the second passband to be adjusted to a higher frequency when transmitting signals in the first communication band. In other words, the second filter 22 shifts the second passband to a higher frequency when transmitting signals in the first communication band.

[0040] (2.10) Third Filter The third filter 23 shown in Figure 1 is a filter having a third passband. The third passband includes the transmission band of the second communication band. The third filter 23 is a transmission filter that allows the second transmission signal of the second communication band to pass through.

[0041] The third filter 23 is located between the second power amplifier 32 and the antenna terminal 71 in the second transmission path T2 that connects the input terminal 73 and the antenna terminal 71. More specifically, the third filter 23 is connected to the second power amplifier 32 and the switch 5 in the second transmission path T2. The third filter 23 allows the second transmission signal of the second communication band to pass through from the high-frequency signals input from the external circuit.

[0042] (2.11) The fourth filter 24 shown in Figure 1 is a filter having a fourth passband. The fourth passband includes the transmission band of the third communication band. The fourth filter 24 is a transmission filter that allows the third transmission signal of the third communication band to pass through.

[0043] The fourth filter 24 is provided between the third power amplifier 33 and the antenna terminal 71 in the third transmission path T3 that connects the input terminal 74 and the antenna terminal 71. More specifically, the fourth filter 24 is connected to the third power amplifier 33 and the switch 5 in the third transmission path T3. The fourth filter 24 allows the third transmission signal in the third communication band to pass among the high-frequency signals input from an external circuit.

[0044] (2.12) Fifth Filter The fifth filter 25 shown in FIG. 1 is a filter having a fifth passband. The fifth passband includes the reception band of the third communication band. The fifth filter 25 is a reception filter that allows the third reception signal in the third communication band to pass.

[0045] The fifth filter 25 is provided between the antenna terminal 71 and the third low-noise amplifier 43 in the third reception path R3 that connects the antenna terminal 71 and the output terminal 77. More specifically, the fifth filter 25 is connected to the switch 5 and the third low-noise amplifier 43 in the third reception path R3. The fifth filter 25 allows the third reception signal in the third communication band to pass among the high-frequency signals input from the antenna terminal 71.

[0046] (2.13) Switch The switch 5 is a switch that switches the path (transmission path, reception path) to be connected to the antenna 91 described later as shown in FIG. 1. The switch 5 is configured to connect at least one of the first filter 21, the second filter 22, the third filter 23, the fourth filter 24, and the fifth filter 25 to the antenna terminal 71. For example, the switch 5 has functions of connecting the first filter 21 and the second filter 22 to the antenna terminal 71, connecting the second filter 22 and the third filter 23 to the antenna terminal 71, and connecting the fourth filter 24 and the fifth filter 25 to the antenna terminal 71.

[0047] As shown in FIG. 1, switch 5 has a common terminal 51, a first selection terminal 52, a second selection terminal 53, a third selection terminal 54, a fourth selection terminal 55, and a fifth selection terminal 56. The common terminal 51 is connected to the antenna terminal 71. The first selection terminal 52 is connected to the first filter 21. The second selection terminal 53 is connected to the second filter 22. The third selection terminal 54 is connected to the third filter 23. The fourth selection terminal 55 is connected to the fourth filter 24. The fifth selection terminal 56 is connected to the fifth filter 25.

[0048] Switch 5 is a switch capable of simultaneously connecting two or more of a plurality of selection terminals (the first selection terminal 52, the second selection terminal 53, the third selection terminal 54, the fourth selection terminal 55, the fifth selection terminal 56) to the common terminal 51. Switch 5 is a switch capable of one-to-many connection. Switch 5 is, for example, a switch IC. Switch 5 is controlled by, for example, a signal processing circuit 92 described later. Switch 5 switches the connection state between the common terminal 51 and the plurality of selection terminals (the first selection terminal 52, the second selection terminal 53, the third selection terminal 54, the fourth selection terminal 55, the fifth selection terminal 56) according to a control signal from the RF signal processing circuit 93 of the signal processing circuit 92.

[0049] (2.14) First communication band, second communication band, and third communication band The first communication band is, for example, Band14. The transmission band of Band14 is 788 MHz or more and 798 MHz or less. The reception band of Band14 is 758 MHz or more and 768 MHz or less. The first communication band may be, for example, Band13. The transmission band of Band13 is 777 MHz or more and 787 MHz or less. The reception band of Band13 is 746 MHz or more and 756 MHz or less.

[0050] The second communication band is, for example, Band 28. The transmission bandwidth of Band 28 is 703 MHz to 748 MHz. The reception bandwidth of Band 28 is 758 MHz to 803 MHz. The transmission bandwidth of Band 28A is 703 MHz to 733 MHz, and the transmission bandwidth of Band 28B is 718 MHz to 748 MHz. The reception bandwidth of Band 28A is 758 MHz to 788 MHz, and the reception bandwidth of Band 28B is 773 MHz to 803 MHz.

[0051] The receiving bandwidth of the second communication band is wider than the transmitting bandwidth of the first communication band. The receiving bandwidth of the second communication band includes the first bandwidth and the second bandwidth. The first bandwidth is the bandwidth that overlaps with the receiving bandwidth of the first communication band. The second bandwidth is the bandwidth that overlaps with the transmitting bandwidth of the first communication band. In addition, the transmitting bandwidth of the second communication band includes the third bandwidth. The third bandwidth is the bandwidth that overlaps with the receiving bandwidth of the first communication band.

[0052] The third communication band is, for example, Band 20. The transmission bandwidth of Band 20 is between 832 MHz and 862 MHz. The reception bandwidth of Band 20 is between 791 MHz and 821 MHz.

[0053] (2.15) Details of the second filter Next, the details of the second filter 22 will be described with reference to the drawings.

[0054] The second filter 22 has a ladder-type resonant circuit, as shown in Figure 2. The first end of the second filter 22 is connected to switch 5 (see Figure 1), and the second end of the second filter 22 is connected to the first power amplifier 31 (see Figure 1) and the second low-noise amplifier 42 (see Figure 1). When transmitting signals in the first communication band, the first end of the second filter 22 is the output end where the high-frequency signal (transmitted signal) is output, and the second end of the second filter 22 is the input end where the high-frequency signal (transmitted signal) is input. When transmitting signals in the second communication band, the first end of the second filter 22 is the input end where the high-frequency signal (received signal) is input, and the second end of the second filter 22 is the output end where the high-frequency signal (received signal) is output.

[0055] The second filter 22 includes a plurality of (three in the example of Figure 2) series arm resonators SR1 to SR3, a plurality of (three in the example of Figure 2) parallel arm resonators PR1 to PR3, a plurality of (two in the example of Figure 2) parallel arm capacitors C11 and C12, a series arm capacitor C2, switches SW11 to SW13, and switch SW2.

[0056] Multiple series arm resonators SR1 to SR3 are provided in the first transmission path T1 (see Figure 1) and the second reception path R2 (see Figure 1). The multiple series arm resonators SR1 to SR3 are connected in series in the order of series arm resonator SR1, series arm resonator SR2, and series arm resonator SR3, from the switch 5 side toward the second low-noise amplifier 42 side.

[0057] Multiple parallel arm resonators PR1 to PR3 are provided in the path between the first transmission path T1 and the second reception path R2 and the ground. More specifically, the first end of parallel arm resonator PR1 is connected to node N1 between the series arm resonator SR1 and the series arm resonator SR2 in the first transmission path T1 and the second reception path R2, and the second end of parallel arm resonator PR1 is connected to the ground. The first end of parallel arm resonator PR2 is connected to node N2 between the series arm resonator SR2 and the series arm resonator SR3 in the first transmission path T1 and the second reception path R2, and the second end of parallel arm resonator PR2 is connected to the ground. The first end of parallel arm resonator PR3 is connected to node N3 between the series arm resonator SR3 and the second low-noise amplifier 42 in the first transmission path T1 and the second reception path R2, and the second end of parallel arm resonator PR3 is connected to the ground. The parallel arm resonator PR1 is the closest of the multiple parallel arm resonators PR1 to PR3 to the antenna terminal 71 (see Figure 1).

[0058] Parallel arm capacitors C11 and C12 are connected in series between at least one of the multiple parallel arm resonators PR1 to PR3, specifically parallel arm resonator PR1, and ground. Parallel arm capacitor C12 is connected in parallel to parallel arm capacitor C11. The first end of parallel arm capacitor C11 is connected to parallel arm resonator PR1, and the second end of parallel arm capacitor C11 is connected to ground. The first end of parallel arm capacitor C12 is also connected to parallel arm resonator PR1, and the second end of parallel arm capacitor C12 is connected to ground.

[0059] Multiple switches SW11 to SW13 select a connection to at least one parallel arm resonator PR1 from among the parallel arm capacitor C11, the parallel arm capacitor C12, and ground. More specifically, switch SW11 is connected in series with the parallel arm capacitor C11, and switch SW12 is connected in series with the parallel arm capacitor C12. Switch SW13 is located between the parallel arm resonator PR1 and ground. Switch SW11 switches between a first state in which the parallel arm resonator PR1 and the parallel arm capacitor C11 are conductive, and a second state in which the parallel arm resonator PR1 and the parallel arm capacitor C11 are not conductive. Switch SW12 switches between a first state in which the parallel arm resonator PR1 and the parallel arm capacitor C12 are conductive, and a second state in which the parallel arm resonator PR1 and the parallel arm capacitor C12 are not conductive. Switch SW13 switches between a first state in which the parallel arm resonator PR1 is directly connected to ground, and a second state in which the parallel arm resonator PR1 is not directly connected to ground.

[0060] The series arm capacitor C2 is connected in parallel to at least one of the series arm resonators SR1 to SR3, specifically to series arm resonator SR1. Switch SW2 is connected in series to the series arm capacitor C2. Switch SW2 switches between a first state in which the series arm capacitor C2 is conductive and a second state in which the series arm capacitor C2 is not conductive.

[0061] Capacitors C31 and C32 are connected to the second filter 22, as shown in Figure 2. Capacitor C31 is connected between the second filter 22 and the switch 5 (see Figure 1). Capacitor C32 is connected between the second filter 22 and the first power amplifier 31 (see Figure 1) and the second low-noise amplifier 42 (see Figure 1).

[0062] (3) Operation of the high-frequency module Next, the operation of the high-frequency module 1 according to Embodiment 1 will be described with reference to Figures 1 to 4.

[0063] (3.1) Communication of signals in the first communication band The operation of the high-frequency module 1 during communication of signals in the first communication band will be described below. The first communication band is Band 13 or Band 14.

[0064] Switch 5 connects the first filter 21 and the second filter 22 to the antenna terminal 71 when transmitting signals in the first communication band. In other words, when transmitting signals in the first communication band, switch 5 connects the first selection terminal 52 and the second selection terminal 53 to the common terminal 51.

[0065] The second filter 22 is configured to have a variable second passband so as to attenuate the first band that overlaps with the receiving band of the first communication band ("B14_Rx" in Figure 3) when transmitting signals in the first communication band. In other words, when transmitting signals in the first communication band, the second filter 22 changes the second passband so as to attenuate the first band that overlaps with the receiving band of the first communication band, as shown in Figure 4. As shown in Figure 4, the amount of attenuation on the low-frequency side increases in the passband of the second filter 22, and the passband of the second filter 22 changes from characteristic A2 to characteristic A1.

[0066] (3.2) Communication of signals in the second communication band The operation of the high-frequency module 1 during communication of signals in the second communication band will be described below. The second communication band is Band 28.

[0067] When transmitting signals in the second communication band, switch 5 connects the second filter 22 and the third filter 23 to the antenna terminal 71. When transmitting signals in the second communication band, switch 5 does not connect the first filter 21 to the antenna terminal 71. In other words, when transmitting signals in the second communication band, switch 5 connects the second selection terminal 53 and the third selection terminal 54 to the common terminal 51, and does not connect the first selection terminal 52 to the common terminal 51.

[0068] The second filter 22 modifies the second passband to include the first band which overlaps with the receiving band of the first communication band ("B14_Rx" in Figure 3) when transmitting signals in the second communication band. When transmitting signals in the second communication band, the passband of the second filter 22 is characteristic A2 as shown in Figure 4.

[0069] (3.3) Communication of signals in the third communication band The operation of the high-frequency module 1 during communication of signals in the third communication band will be described below. The third communication band is Band 20.

[0070] Switch 5 connects the fourth filter 24 and the fifth filter 25 to the antenna terminal 71 when transmitting signals in the third communication band. When transmitting signals in the third communication band, switch 5 does not connect the first filter 21, the second filter 22, and the third filter 23 to the antenna terminal 71.

[0071] (4) Communication device Hereinafter, a communication device 9 equipped with a high-frequency module 1 according to Embodiment 1 will be described.

[0072] As shown in Figure 1, the communication device 9 according to Embodiment 1 comprises a high-frequency module 1, an antenna 91, and a signal processing circuit 92. The communication device 9 is, for example, a mobile terminal (e.g., a smartphone). However, the communication device 9 is not limited to a mobile terminal; it may also be, for example, a wearable device (e.g., a smartwatch).

[0073] The high-frequency module 1 is configured to amplify the transmission signal (high-frequency signal) from the signal processing circuit 92 and output it to the antenna 91. The high-frequency module 1 is also configured to amplify the received signal (high-frequency signal) received by the antenna 91 and output it to the signal processing circuit 92. The high-frequency module 1 is controlled, for example, by the signal processing circuit 92.

[0074] The high-frequency module 1 is a module that supports, for example, 4G (fourth-generation mobile communication) standards and 5G (fifth-generation mobile communication) standards. The 4G standard is, for example, the 3GPP (registered trademark, Third Generation Partnership Project) LTE (registered trademark, Long Term Evolution) standard. The 5G standard is, for example, 5G NR (New Radio). The high-frequency module 1 is a module that supports carrier aggregation and dual connectivity.

[0075] In the communication device 9, the high-frequency module 1 is electrically connectable to an external circuit board (not shown). The external circuit board corresponds to, for example, the motherboard of a mobile terminal or communication device. The statement that the high-frequency module 1 is electrically connectable to the external circuit board includes not only cases where the high-frequency module 1 is directly mounted on the external circuit board, but also cases where the high-frequency module 1 is indirectly mounted on the external circuit board. Indirect mounting of the high-frequency module 1 to the external circuit board includes cases where the high-frequency module 1 is mounted on another high-frequency module mounted on the external circuit board, etc.

[0076] (4.1) Antenna The antenna 91 is connected to the antenna terminal 71 of the high-frequency module 1, as shown in Figure 1. The antenna 91 has a transmitting function that radiates the transmission signal output from the high-frequency module 1 as radio waves, and a receiving function that receives the reception signal as radio waves from the outside and outputs it to the high-frequency module 1.

[0077] (4.2) Signal Processing Circuit The signal processing circuit 92 is connected to the high-frequency module 1 as shown in Figure 1. The signal processing circuit 92 processes the high-frequency signals passing through the high-frequency module 1. More specifically, the signal processing circuit 92 is configured to process the received signals received from the high-frequency module 1. The signal processing circuit 92 is also configured to process the transmitted signals output to the high-frequency module 1.

[0078] The signal processing circuit 92 includes an RF signal processing circuit 93 and a baseband signal processing circuit 94.

[0079] (4.2.1) RF signal processing circuit The RF signal processing circuit 93 is, for example, an RFIC (Radio Frequency Integrated Circuit) and performs signal processing on high-frequency signals (transmitted signals and received signals).

[0080] The RF signal processing circuit 93 performs signal processing on the received signal output from the high-frequency module 1 and outputs the processed received signal to the baseband signal processing circuit 94. Specifically, the RF signal processing circuit 93 performs signal processing such as down-conversion on the received signal output from the receiving path of the high-frequency module 1 and outputs the processed received signal to the baseband signal processing circuit 94.

[0081] The RF signal processing circuit 93 performs signal processing on the transmission signal output from the baseband signal processing circuit 94 and outputs the processed transmission signal to the high-frequency module 1. Specifically, the RF signal processing circuit 93 performs signal processing such as upconversion on the transmission signal output from the baseband signal processing circuit 94 and outputs the processed transmission signal to the transmission path of the high-frequency module 1.

[0082] (4.2.2) Baseband signal processing circuit The baseband signal processing circuit 94 is, for example, a BBIC (Baseband Integrated Circuit).

[0083] The baseband signal processing circuit 94 performs predetermined signal processing on the signal from the RF signal processing circuit 93. More specifically, the baseband signal processing circuit 94 outputs the received signal received from the RF signal processing circuit 93 to the outside. The received signal processed by the baseband signal processing circuit 94 is used, for example, as an image signal for image display or as an audio signal for telephone communication.

[0084] The baseband signal processing circuit 94 performs predetermined signal processing on signals from outside the signal processing circuit 92. More specifically, the baseband signal processing circuit 94 generates a transmission signal from baseband signals (e.g., audio signals and image signals) from outside the signal processing circuit 92, and outputs the generated transmission signal to the RF signal processing circuit 93.

[0085] (5) The high-frequency module 1 according to the first embodiment of the effect comprises a first filter 21, a second filter 22, an antenna terminal 71, and a switch 5. The first filter 21 has a first passband. The first passband includes the receiving band of the first communication band. The second filter 22 has a second passband. The second passband includes the transmitting band of the first communication band and the receiving band of the second communication band. The antenna terminal 71 is a terminal connected to the antenna 91. The switch 5 connects at least one of the first filter 21 and the second filter 22 to the antenna terminal 71. The receiving band of the second communication band includes a first band and a second band. The first band is a band that overlaps with the receiving band of the first communication band. The second band is a band that overlaps with the transmitting band of the first communication band. The second filter 22 is a variable filter.

[0086] According to the high-frequency module 1 of Embodiment 1, when transmitting a signal in the first communication band, the first band in the second passband of the second filter 22 where the receiving band of the second communication band overlaps with the receiving band of the first communication band can be attenuated, thus enabling communication over overlapping communication bands. Furthermore, according to the high-frequency module 1 of Embodiment 1, when transmitting a signal in the first communication band, the high-frequency and low-frequency sides of the transmission band of the first communication band can be sufficiently secured in the second passband of the second filter 22, thus reducing transmission loss degradation over overlapping communication bands. As a result, the high-frequency module 1 of Embodiment 1 enables communication over overlapping communication bands and reduces transmission loss degradation.

[0087] In the high-frequency module 1 according to Embodiment 1, the second filter 22a is configured to allow the second passband to be variably adjusted to the high-frequency side when transmitting signals in the first communication band.

[0088] According to the high-frequency module 1 of Embodiment 1, the second filter 22a can stably transmit signals in the first communication band.

[0089] The high-frequency module 1 according to Embodiment 1 further comprises a third filter 23. The third filter 23 has a third passband. The third passband includes the transmission band of the second communication band. The transmission band of the second communication band includes a third band. The third band overlaps with the transmission band of the first communication band. The switch 5 has a common terminal 51, a first selection terminal 52, a second selection terminal 53, and a third selection terminal 54. The common terminal 51 is connected to the antenna terminal 71. The first selection terminal 52 is connected to the first filter 21. The second selection terminal 53 is connected to the second filter 22. The third selection terminal 54 is connected to the third filter 23.

[0090] According to the high-frequency module 1 of Embodiment 1, when transmitting signals in the first communication band, communication is possible on the co-banded communication band.

[0091] In the high-frequency module 1 according to Embodiment 1, the receiving bandwidth of the second communication band is wider than the transmitting bandwidth of the first communication band.

[0092] According to the high-frequency module 1 of Embodiment 1, compared to the case where a filter having a passband that includes the transmission band of the first communication band is used, the filter can be designed without considering variable factors such as manufacturing variations and temperature deviations.

[0093] The communication device 9 according to Embodiment 1 comprises a high-frequency module 1 and a signal processing circuit 92. The signal processing circuit 92 is connected to the high-frequency module 1.

[0094] According to the communication device 9 of Embodiment 1, in the high-frequency module 1, when transmitting a signal in the first communication band, the first band of the second passband of the second filter 22 where the receiving band of the second communication band overlaps with the receiving band of the first communication band can be attenuated, so that communication is possible over overlapping communication bands. Furthermore, according to the communication device 9 of Embodiment 1, in the high-frequency module 1, when transmitting a signal in the first communication band, the high-frequency and low-frequency sides of the transmission band of the first communication band can be sufficiently secured in the second passband of the second filter 22, so that the degradation of transmission loss is reduced over overlapping communication bands. Thus, according to the communication device 9 of Embodiment 1, communication is possible over overlapping communication bands and the degradation of transmission loss is reduced.

[0095] (Embodiment 2) The high-frequency module 1 according to Embodiment 2 differs from the high-frequency module 1 according to Embodiment 1 (see Figure 1) in that it includes a second filter 22a and a third filter 23a, as shown in Figure 5. Regarding the high-frequency module 1 according to Embodiment 2, components similar to those in the high-frequency module 1 according to Embodiment 1 are denoted by the same reference numerals and their descriptions are omitted.

[0096] (1) The high-frequency module 1 according to the second embodiment, as shown in Figure 5, comprises a first filter 21, a second filter 22a, a third filter 23a, a fourth filter 24, a first power amplifier 31, a second power amplifier 32, a third power amplifier 33, a first low-noise amplifier 41, a second low-noise amplifier 42a, a switch 5a, and a plurality of (six in the example of Figure 5) external connection terminals 7. The high-frequency module 1 according to the second embodiment comprises a second filter 22a and a third filter 23a instead of the second filter 22 and the third filter 23. The high-frequency module 1 according to the second embodiment also comprises a second low-noise amplifier 42a instead of the second low-noise amplifier 42. Furthermore, the high-frequency module 1 according to the second embodiment also comprises a switch 5a instead of the switch 5.

[0097] (1.1) External Connection Terminals The multiple external connection terminals 7 of Embodiment 2 include, as shown in Figure 5, an antenna terminal 71, multiple (three in the example of Figure 5) input terminals 72 to 74, and multiple (two in the example of Figure 5) output terminals 75 and 76. The antenna terminal 71 is connected to the antenna 91. The multiple input terminals 72 to 74 are connected to the signal processing circuit 92. The multiple output terminals 75 and 76 are connected to the signal processing circuit 92.

[0098] (1.2) Second Filter The second filter 22a shown in Figure 5 is a filter having a second passband. The second filter 22a is a variable filter. The second passband includes the transmission band of the first communication band, the reception band of the second communication band, and the reception band of the third communication band. The second filter 22a is a transmit / receive filter that allows the first transmit signal of the first communication band to pass through, and the second receive signal of the second communication band and the third receive signal of the third communication band to pass through. Note that the configuration and function of the second filter 22a of Embodiment 2 are the same as those of the second filter 22 of Embodiment 1 (see Figure 1), so the explanation will be omitted.

[0099] (1.3) Third Filter The third filter 23a shown in Figure 5 is a filter having a third passband. The third passband includes the transmission band of the second communication band. The third filter 23a is a transmission filter that allows the second transmission signal of the second communication band to pass through. Regarding the third filter 23a of Embodiment 2, the same configuration and function as the third filter 23 of Embodiment 1 (see Figure 1) will not be explained.

[0100] The third filter 23a is a variable filter, as shown in Figure 5. The third filter 23a changes the third passband when transmitting signals in the first communication band.

[0101] (1.4) Switch The switch 5a of the second embodiment has a common terminal 57, a first selection terminal 58, and a second selection terminal 59, as shown in Figure 5. The common terminal 57 is connected to the antenna terminal 71. The first selection terminal 58 is connected to the first filter 21. The second selection terminal 59 is connected to the second filter 22a, the third filter 23a, and the fourth filter 24. Regarding the switch 5a of the second embodiment, the same configuration and functions as the switch 5 of the first embodiment (see Figure 1) will not be explained.

[0102] Switch 5a is configured to connect at least one of the first filter 21, second filter 22a, third filter 23a, and fourth filter 24 to the antenna terminal 71. For example, switch 5a has the function of connecting all of the first filter 21, second filter 22a, third filter 23a, and fourth filter 24 to the antenna terminal 71, and the function of connecting only the second filter 22a, third filter 23a, and fourth filter 24 to the antenna terminal 71.

[0103] (1.5) First Communication Band and Second Communication Band The receiving band of the second communication band includes the first band and the second band. The first band is the band that overlaps with the receiving band of the first communication band. The second band is the band that overlaps with the transmitting band of the first communication band.

[0104] The transmission bandwidth of the second communication band includes a third bandwidth, similar to that in Embodiment 1. The third bandwidth is the bandwidth that overlaps with the transmission bandwidth of the first communication band.

[0105] The receiving bandwidth of the second communication band is wider than the transmitting bandwidth of the first communication band.

[0106] The first communication band is, for example, Band 14. The first communication band may also be, for example, Band 13. The second communication band is, for example, Band 28. The third communication band is, for example, Band 20.

[0107] (1.6) Details of the second filter Next, the details of the second filter 22a will be described with reference to the drawings.

[0108] As shown in Figure 6, the second filter 22a has a ladder-type resonant circuit. The first end of the second filter 22a is connected to switch 5a (see Figure 5), and the second end of the second filter 22a is connected to the first power amplifier 31 (see Figure 5) and the second low-noise amplifier 42a (see Figure 5). When transmitting signals in the first communication band, the first end of the second filter 22a is the output end where the high-frequency signal (transmitted signal) is output, and the second end of the second filter 22a is the input end where the high-frequency signal (transmitted signal) is input. When transmitting signals in the second communication band, the first end of the second filter 22a is the input end where the high-frequency signal (received signal) is input, and the second end of the second filter 22a is the output end where the high-frequency signal (received signal) is output.

[0109] The second filter 22a includes a plurality of series arm resonators SR1 to SR3 (three in the example of Figure 6), a plurality of parallel arm resonators PR1 to PR3 (three in the example of Figure 6), a parallel arm capacitor C4, and a switch SW3.

[0110] Multiple series arm resonators SR1 to SR3 are provided in the first transmission path T1 (see Figure 5) and the second reception path R2 (see Figure 5). The multiple series arm resonators SR1 to SR3 are connected in series in the order of series arm resonator SR1, series arm resonator SR2, and series arm resonator SR3, from the switch 5a side toward the second low-noise amplifier 42a side.

[0111] Multiple parallel arm resonators PR1 to PR3 are provided in the path between the first transmission path T1 and the second reception path R2 and the ground. More specifically, the first end of parallel arm resonator PR1 is connected to node N1 between the series arm resonator SR1 and the series arm resonator SR2 in the first transmission path T1 and the second reception path R2, and the second end of parallel arm resonator PR1 is connected to the ground. The first end of parallel arm resonator PR2 is connected to node N2 between the series arm resonator SR2 and the series arm resonator SR3 in the first transmission path T1 and the second reception path R2, and the second end of parallel arm resonator PR2 is connected to the ground. The first end of parallel arm resonator PR3 is connected to node N3 between the series arm resonator SR3 and the first low-noise amplifier 41 in the first transmission path T1 and the second reception path R2, and the second end of parallel arm resonator PR3 is connected to the ground. The parallel arm resonator PR1 is the closest of the multiple parallel arm resonators PR1 to PR3 to the antenna terminal 71 (see Figure 5).

[0112] The parallel arm capacitor C4 is connected in series with at least one of the multiple parallel arm resonators PR1 to PR3. More specifically, the parallel arm capacitor C4 is connected in series with the parallel arm resonator PR1.

[0113] Switch SW3 is connected in series with the parallel arm resonator PR1 and in parallel with the parallel arm capacitor C4. Switch SW3 switches between a first state in which the parallel arm resonator PR1 is directly connected to ground and a second state in which the parallel arm resonator PR1 is not directly connected to ground.

[0114] Capacitors C51 and C52 are connected to the second filter 22a, as shown in Figure 6. Capacitor C51 is connected between the second filter 22a and switch 5a (see Figure 5). Capacitor C52 is connected between the second filter 22a and the first power amplifier 31 (see Figure 1) and the second low-noise amplifier 42a (see Figure 5).

[0115] (1.7) Details of the third filter Next, the details of the third filter 23a will be described with reference to the drawings.

[0116] The third filter 23a has a ladder-type resonant circuit, as shown in Figure 7. The first end of the third filter 23a is connected to switch 5a (see Figure 5), and the second end of the third filter 23a is connected to the second power amplifier 32 (see Figure 5). The first end of the third filter 23a is the output terminal where the high-frequency signal (transmit signal) is output, and the second end of the third filter 23a is the input terminal where the high-frequency signal (transmit signal) is input.

[0117] The third filter 23a includes a plurality of (three in the example of Figure 7) series arm resonators SR4 to SR6, a plurality of (three in the example of Figure 7) parallel arm resonators PR4 to PR6, a series arm capacitor C6, and a switch SW4.

[0118] Multiple series arm resonators SR4 to SR6 are provided in the second transmission path T2 (see Figure 5). The multiple series arm resonators SR4 to SR6 are connected in series from the switch 5a side toward the second power amplifier 32 side in the order of series arm resonator SR4, series arm resonator SR5, and series arm resonator SR6.

[0119] Multiple parallel arm resonators PR4 to PR6 are located in the path between the second transmission path T2 and ground. More specifically, the first end of parallel arm resonator PR4 is connected to node N4 in the second transmission path T2 between series arm resonators SR4 and SR5, and the second end of parallel arm resonator PR4 is connected to ground. The first end of parallel arm resonator PR5 is connected to node N5 in the second transmission path T2 between series arm resonators SR5 and SR6, and the second end of parallel arm resonator PR5 is connected to ground. The first end of parallel arm resonator PR6 is connected to node N6 in the second transmission path T2 between series arm resonator SR6 and the second power amplifier 32, and the second end of parallel arm resonator PR6 is connected to ground. Of the multiple parallel arm resonators PR4 to PR6, parallel arm resonator PR4 is closest to the antenna terminal 71 (see Figure 5).

[0120] The series arm capacitor C6 is connected in parallel to at least one of the multiple series arm resonators SR4 to SR6. More specifically, the series arm capacitor C6 is connected in parallel to the series arm resonator SR4. Switch SW4 is connected in series to the series arm capacitor C6. Switch SW4 switches between a first state in which the series arm capacitor C6 is conductive and a second state in which the series arm capacitor C6 is not conductive.

[0121] Capacitors C71 and C72 are connected to the third filter 23a, as shown in Figure 7. Capacitor C71 is connected between the third filter 23a and switch 5a (see Figure 5). Capacitor C72 is connected between the third filter 23a and the second power amplifier 32 (see Figure 5).

[0122] (2) Operation Next, the operation of the high-frequency module 1 according to Embodiment 2 will be described with reference to Figures 5 to 11.

[0123] (2.1) Signal communication in the first communication band (2.1.1) Band 13 The operation of the high-frequency module 1 when the first communication band is Band 13 will be explained.

[0124] As shown in Figure 9, when transmitting signals in the first communication band, switch 5a connects the first filter 21 and the second filter 22a to the antenna terminal 71 (see Figure 5). In other words, when transmitting signals in the first communication band, switch 5a connects the first selection terminal 58 and the second selection terminal 59 to the common terminal 57.

[0125] The second filter 22a modifies the second passband to attenuate the first band, which is close to the receiving band of the first communication band ("B13_Rx" in Figure 8), when transmitting signals in the first communication band. In the passband of the second filter 22, the attenuation on the low-frequency side increases, and the passband of the second filter 22 changes from characteristic A2 to characteristic A1 (see Figure 4).

[0126] The third filter 23a modifies the third passband to attenuate the bandwidth that overlaps with the receiving bandwidth of the first communication band ("B13_Rx" in Figure 8) when transmitting signals in the first communication band. In the passband of the third filter 23a, the attenuation on the high-frequency side becomes larger. The passband of the third filter 23a is characteristic B2 shown in Figure 11.

[0127] (2.1.2) Band 14 The operation of the high-frequency module 1 when the first communication band is Band 14 will be described.

[0128] As shown in Figure 9, when transmitting signals in the first communication band, switch 5a connects the first filter 21 and the second filter 22a to the antenna terminal 71. In other words, when transmitting signals in the first communication band, switch 5a connects the first selection terminal 58 and the second selection terminal 59 to the common terminal 57.

[0129] The second filter 22a modifies the second passband to attenuate the first band that overlaps with the receiving band of the first communication band ("B14_Rx" in Figure 8) when transmitting signals in the first communication band. In the passband of the second filter 22a, the attenuation on the low-frequency side increases, and the passband of the second filter 22 changes from characteristic A2 to characteristic A1 (see Figure 4).

[0130] (2.2) Communication of signals in the second communication band The operation of the high-frequency module 1 during communication of signals in the second communication band will be described below. The second communication band is Band 28.

[0131] As shown in Figure 10, when transmitting signals in the second communication band, switch 5a connects the second filter 22a and the third filter 23a to the antenna terminal 71 (see Figure 5). When transmitting signals in the second communication band, switch 5a does not connect the first filter 21 to the antenna terminal 71. In other words, when transmitting signals in the second communication band, switch 5a connects the second selection terminal 59 to the common terminal 57 and does not connect the first selection terminal 58.

[0132] The second filter 22a is configured to vary its second passband so that, when transmitting signals in the second communication band, it includes the first band that overlaps with the receiving band of the first communication band ("B14_Rx" in Figure 8). In other words, the second filter 22a changes its second passband so that, when transmitting signals in the second communication band, it includes the first band that overlaps with the receiving band of the first communication band. When transmitting signals in the second communication band, the passband of the second filter 22 is characteristic A2 as shown in Figure 4.

[0133] (2.3) Communication of signals in the third communication band The operation of the high-frequency module 1 during communication of signals in the third communication band will be described below. The third communication band is Band 20.

[0134] As shown in Figure 10, when transmitting signals in the third communication band, switch 5a connects the second filter 22a and the fourth filter 24 to the antenna terminal 71. When transmitting signals in the third communication band, switch 5a does not connect the first filter 21 to the antenna terminal 71. In other words, when transmitting signals in the third communication band, switch 5a connects the second selection terminal 59 to the common terminal 57 and does not connect the first selection terminal 58.

[0135] The third filter 23a modifies the third passband to include the overlapping bandwidth of the first communication band ("B13_Rx" in Figure 8) when transmitting signals in the third communication band. The passband of the third filter 23a is characteristic B1 shown in Figure 11.

[0136] (3) Communication device The following describes the communication device 9 equipped with the high-frequency module 1 according to Embodiment 2.

[0137] The communication device 9 according to Embodiment 2, like the communication device 9 according to Embodiment 1, comprises a high-frequency module 1, an antenna 91, and a signal processing circuit 92, as shown in Figure 5. The signal processing circuit 92 comprises an RF signal processing circuit 93 and a baseband signal processing circuit 94. The communication device 9 is, for example, a mobile terminal (e.g., a smartphone). However, the communication device 9 is not limited to a mobile terminal; it may also be, for example, a wearable terminal (e.g., a smartwatch). The antenna 91 and signal processing circuit 92 of the communication device 9 according to Embodiment 2 have the same functions as the antenna 91 and signal processing circuit 92 of the communication device 9 according to Embodiment 1.

[0138] (4) The high-frequency module 1 according to the second embodiment of the effect comprises a first filter 21, a second filter 22a, an antenna terminal 71, and a switch 5a. The first filter 21 has a first passband. The first passband includes the receiving band of the first communication band. The second filter 22a has a second passband. The second passband includes the transmitting band of the first communication band and the receiving band of the second communication band. The antenna terminal 71 is a terminal connected to the antenna 91. The switch 5a connects at least one of the first filter 21 and the second filter 22a to the antenna terminal 71. The receiving band of the second communication band includes a first band and a second band. The first band is a band that overlaps with the receiving band of the first communication band. The second band is a band that overlaps with the transmitting band of the first communication band. The second filter 22a is a variable filter.

[0139] According to the high-frequency module 1 of Embodiment 2, when transmitting a signal in the first communication band, the first band in the second passband of the second filter 22a where the receiving band of the second communication band overlaps with the receiving band of the first communication band can be attenuated, thus enabling communication over overlapping communication bands. Furthermore, according to the high-frequency module 1 of Embodiment 2, when transmitting a signal in the first communication band, the high-frequency and low-frequency sides of the transmission band of the first communication band can be sufficiently secured in the second passband of the second filter 22a, thus reducing transmission loss degradation over overlapping communication bands. As a result, the high-frequency module 1 of Embodiment 2, like the high-frequency module 1 of Embodiment 1, enables communication over overlapping communication bands and reduces transmission loss degradation.

[0140] The high-frequency module 1 according to Embodiment 2 further comprises a third filter 23a. The third filter 23a has a third passband. The third passband includes the transmission band of the second communication band. The transmission band of the second communication band includes the third band. The third band overlaps with the transmission band of the first communication band. The switch 5a has a common terminal 57, a first selection terminal 58, and a second selection terminal 59. The common terminal 57 is connected to the antenna terminal 71. The first selection terminal 58 is connected to the first filter 21. The second selection terminal 59 is connected to the second filter 22a and the third filter 23a. The third filter 23a is a variable filter.

[0141] According to the high-frequency module 1 of Embodiment 2, when transmitting a signal in the first communication band, the third passband of the third filter 23a can attenuate the third band in which the transmission band of the second communication band overlaps with the transmission band of the third communication band, thus enabling communication over overlapping communication bands.

[0142] The embodiments and modifications described above are only a part of the various embodiments and modifications of the present invention. Furthermore, the embodiments and modifications can be modified in various ways depending on the design, etc., as long as the objectives of the present invention are achieved.

[0143] 1 High-frequency module 21 First filter 22, 22a Second filter 23, 23a Third filter 24 Fourth filter 25 Fifth filter 31 First power amplifier 32 Second power amplifier 33 Third power amplifier 41 First low-noise amplifier 42, 42a Second low-noise amplifier 43 Third low-noise amplifier 5, 5a Switch 51 Common terminal 52 First selection terminal 53 Second selection terminal 54 Third selection terminal 55 Fourth selection terminal 56 Fifth selection terminal 57 Common terminal 58 First selection terminal 59 Second selection terminal 7 External connection terminals 71 Antenna terminal 72, 73, 74 Input terminals 75, 76, 77 Output terminals 9 Communication device 91 Antenna 92 ​​Signal processing circuit 93 RF signal processing circuit 94 Baseband signal processing circuit SR1, SR2, SR3, SR4, SR5, SR6 Series arm resonators PR1, PR2, PR3, PR4, PR5, PR6 Parallel arm resonators C11, C12, C4 Parallel arm capacitors C2, C6 Series arm capacitors C31, C32 Capacitors C51, C52 Capacitors C71, C72 Capacitors SW11, SW12, SW13, SW2, SW3, SW4 Switches T1 First transmission path T2 Second transmission path T3 Third transmission path R1 First reception path R2 Second reception path R3 Third reception path N1, N2, N3, N4, N5, N6 Nodes A1, A2 Characteristics B1, B2 Characteristics

Claims

1. A high-frequency module comprising: a first filter having a first passband including the receiving band of a first communication band; a second filter having a second passband including the transmitting band of the first communication band and the receiving band of a second communication band; an antenna terminal connected to an antenna; and a switch for connecting at least one of the first filter and the second filter to the antenna terminal, wherein the receiving band of the second communication band includes a first band overlapping with the receiving band of the first communication band and a second band overlapping with the transmitting band of the first communication band, and the second filter is a variable filter.

2. The high-frequency module according to claim 1, wherein the second filter is configured to vary the second passband to the high-frequency side when transmitting signals in the first communication band.

3. The high-frequency module according to claim 1 or 2, wherein the switch connects the first filter and the second filter to the antenna terminal when transmitting a signal in the first communication band, and the second filter is configured to vary the second passband so as to attenuate the first band that overlaps with the receiving band of the first communication band when transmitting a signal in the first communication band.

4. The high-frequency module according to claim 3, wherein the switch connects the second filter to the antenna terminal when transmitting a signal in the second communication band, and the second filter is configured to vary the second passband so as to include the first band that overlaps with the receiving band of the first communication band when transmitting a signal in the second communication band.

5. A high-frequency module according to any one of claims 1 to 4, further comprising a third filter having a third passband including the transmission band of the second communication band, wherein the transmission band of the second communication band includes a third band overlapping with the transmission band of the first communication band, the switch having a common terminal connected to the antenna terminal, a first selection terminal connected to the first filter, and a second selection terminal connected to the second filter and the third filter, wherein the third filter is a variable filter.

6. A high-frequency module according to any one of claims 1 to 4, further comprising a third filter having a third passband including the transmission band of the second communication band, wherein the transmission band of the second communication band includes a third band that overlaps with the transmission band of the first communication band, and the switch has a common terminal connected to the antenna terminal, a first selection terminal connected to the first filter, a second selection terminal connected to the second filter, and a third selection terminal connected to the third filter.

7. The high-frequency module according to claim 5 or 6, wherein the third filter comprises: a plurality of series arm resonators provided in a path connected to the antenna terminal; a plurality of parallel arm resonators provided between the path and ground; a capacitor connected in parallel to at least one of the plurality of series arm resonators; and a switch connected in parallel to the capacitor.

8. The high-frequency module according to any one of claims 1 to 6, wherein the second filter comprises: a plurality of series arm resonators provided in a path connected to the antenna terminal; a plurality of parallel arm resonators provided between the path and ground; a parallel arm capacitor connected in series with at least one of the plurality of parallel arm resonators; and a switch connected in series with the parallel arm capacitor.

9. The high-frequency module according to any one of claims 1 to 6, wherein the second filter comprises: a plurality of series arm resonators provided in a path connected to the antenna terminal; a plurality of parallel arm resonators provided between the path and ground; a plurality of parallel arm capacitors connected in series between at least one of the plurality of parallel arm resonators and ground, and connected in parallel to one another; a switch for selecting the connection to the at least one parallel arm resonator from among the plurality of parallel arm capacitors and ground; a series arm capacitor connected in parallel to at least one of the plurality of series arm resonators; and a switch connected in series to the series arm capacitor.

10. The high-frequency module according to any one of claims 1 to 9, wherein the first filter is a variable filter.

11. The high-frequency module according to any one of claims 1 to 10, wherein the receiving bandwidth of the second communication band is wider than the transmitting bandwidth of the first communication band.

12. The high-frequency module according to claim 11, wherein the first communication band is Band 14 and the second communication band is Band 28.

13. A communication device comprising a high-frequency module according to any one of claims 1 to 12, and a signal processing circuit connected to the high-frequency module.

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