High frequency circuit

Abstract

To provide a high frequency circuit capable of simultaneously transmitting signals on a plurality of bands in low loss.SOLUTION: A high frequency circuit 1 includes: a switch circuit 200 having a common terminal 201, terminals 202, 203 and 204; a signal path P1 connected to the terminal 202 for transmitting a band A signal; a signal path P2 connected to the terminal 203 for transmitting a band B signal; a filter 12 arranged on the signal path P2; a signal path P3 connected to the terminal 204 for transmitting a band D signal which can be simultaneously transmitted with the band A and can be simultaneously transmitted with the band B; a capacitor 310 arranged in series to the signal path P2 between the terminal 203 and the filter 12; an inductor 42 connected between the signal path P2 between the capacitor 310 and the filter 12 and the ground; and a switch circuit 300 having terminals 301 and 302, the terminal 301 being connected to the signal path P2 between the capacitor 310 and the filter 12, and the terminal 302 being connected to the signal path P3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a high-frequency circuit. [Background technology]

[0002] Patent Document 1 (FIG. 9) discloses a front-end circuit including a switch and multiple filters connected to the terminals of the switch. The front-end circuit is configured to be capable of simultaneously transmitting multiple signals in different bands (Carrier Aggregation (CA)). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent Application Publication No. 2020 / 0358516 Summary of the Invention [Problem to be solved by the invention]

[0004] In the front-end circuit (high-frequency circuit) disclosed in Patent Document 1, for example, when a signal of band B7 (band A) and a signal of band B1 / B3 (band B) are transmitted simultaneously, an impedance matching circuit including a capacitance element arranged in series may be arranged between the filter for band B1 / B3 and the switch in order to optimize the impedance of the band B1 / B3 itself.

[0005] However, when the above-mentioned impedance matching circuit is installed, for example, when a signal of band B1 / B3 and a signal of band B32 (band C) are transmitted simultaneously, an unnecessary attenuation pole is formed in the passband of band B32, resulting in an increase in the transmission loss of the signal of band B32.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a high-frequency circuit that can simultaneously transmit signals in multiple bands with low loss. [Means for solving the problem]

[0007] In order to achieve the above object, a high-frequency circuit according to one aspect of the present invention includes: a first switch circuit having a first common terminal, a first terminal, a second terminal, and a third terminal; a first signal path connected to the first terminal; a first filter arranged in the first signal path and having a passband that includes a receive band of a first band; a second signal path connected to the second terminal; a second filter arranged in the second signal path and having a passband that includes the receive band of a second band; a third signal path connected to the third terminal and transmitting a receive signal of a third band that can be transmitted simultaneously with the first band and the second band; a first capacitor arranged in series in the second signal path between the second terminal and the second filter; a first inductor connected between the second signal path between the first capacitor and the second filter and ground; and a second switch circuit having a fourth terminal and a fifth terminal, the fourth terminal connected to the second signal path between the first capacitor and the second filter, and the fifth terminal connected to the third signal path. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a high frequency circuit that can simultaneously transmit signals in multiple bands with low loss. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a circuit configuration diagram of a high-frequency circuit according to an embodiment; [Figure 2A] FIG. 2 is a circuit configuration diagram of a high-frequency circuit according to a first comparative example. [Figure 2B] FIG. 10 is a circuit configuration diagram of a high-frequency circuit according to Comparative Example 2. [Figure 3A] 3 is a circuit state diagram showing a first signal reception mode of the high-frequency circuit according to the embodiment. FIG. [Figure 3B] FIG. 4 is a circuit state diagram illustrating a second signal reception mode of the high-frequency circuit according to the embodiment. [Figure 3C] FIG. 10 is a circuit state diagram showing a third signal reception mode of the high-frequency circuit according to the embodiment. [Figure 3D] FIG. 10 is a circuit state diagram showing a fourth signal reception mode of the high-frequency circuit according to the embodiment. [Figure 3E] FIG. 10 is a circuit state diagram showing a fifth signal reception mode of the high-frequency circuit according to the embodiment. [Figure 4] FIG. 10 is a circuit configuration diagram of a high-frequency circuit according to a first modified example of the embodiment. [Figure 5] FIG. 10 is a circuit configuration diagram of a high-frequency circuit according to a second modification of the embodiment. [Figure 6] FIG. 10 is a circuit configuration diagram of a high-frequency circuit according to a third modified example of the embodiment. [Figure 7] FIG. 10 is a circuit configuration diagram of a high-frequency circuit according to a fourth modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component arrangements, and connection forms shown in the following embodiments are merely examples and are not intended to limit the present invention. Among the components in the following embodiments, components that are not recited in independent claims will be described as optional components. Furthermore, the sizes or size ratios of the components shown in the drawings are not necessarily strict.

[0011] It should be noted that the drawings are schematic diagrams in which emphasis, omission, or adjustment of proportions has been appropriately made to illustrate the present invention, and are not necessarily strictly illustrated, and may differ from the actual shapes, positional relationships, and proportions. In the drawings, the same reference numerals are used to denote substantially the same components, and redundant explanations may be omitted or simplified.

[0012] In the circuit configurations disclosed herein, "connected" includes not only direct connection by connection terminals and / or wiring conductors, but also electrical connection via matching elements or switch circuits. "Connected between A and B" means connected to both A and B between A and B.

[0013] In the present invention, a "terminal" refers to a point where a conductor within an element terminates. Note that a terminal is not limited to a single point, but may be any point (node) on the conductor between elements or the entire conductor, provided that the impedance of the conductor between elements is sufficiently low.

[0014] In addition, in this disclosure, a "signal path" means a transmission line that is composed of a wiring through which a high-frequency transmission signal or a high-frequency reception signal propagates, an electrode directly connected to the wiring, and a terminal directly connected to the wiring or the electrode.

[0015] Furthermore, in the circuit element arrangement of the present disclosure, "circuit element A is arranged in series on path B" means that the signal input terminal and signal output terminal of circuit element A are connected to two wirings that form at least a part of path B, respectively. At least one of the two wirings may be an electrode or a terminal.

[0016] In the following embodiments, the passband of a filter is defined as a frequency band between two frequencies that are 3 dB higher than the minimum value of insertion loss within the passband.

[0017] Furthermore, in the present disclosure, the term "band" refers to at least one of an uplink operating band and a downlink operating band of a frequency band predefined by a standardization organization (e.g., 3GPP (registered trademark), IEEE (Institute of Electrical and Electronics Engineers)), etc., for a communication system built using a radio access technology (RAT). In the present embodiment, examples of the communication system that can be used include, but are not limited to, a Long Term Evolution (LTE) system, a 5th Generation (5G)-New Radio (NR) system, and a Wireless Local Area Network (WLAN) system. Note that the uplink operating band of a frequency band refers to a frequency range designated for uplink within the frequency band. Furthermore, the downlink operating band of a frequency band refers to a frequency range designated for downlink within the frequency band.

[0018] (Embodiment) [1 Circuit configuration of high frequency circuit 1] The circuit configuration of a high-frequency circuit 1 according to this embodiment will be described with reference to Fig. 1. Fig. 1 is a circuit configuration diagram of the high-frequency circuit 1 according to this embodiment. As shown in the figure, the high-frequency circuit 1 according to this embodiment includes filters 11, 12, and 13, switches 21, 22, 23, 24, and 25, signal paths P1, P2, and P3, a matching circuit 31, inductors 41 and 42, an antenna connection terminal 100, and high-frequency output terminals 110, 120, 130, and 140.

[0019] The antenna connection terminal 100 is connected to the antenna 2 and the switch circuit 200 of the high-frequency circuit 1. The high-frequency output terminal 110 is an external connection terminal connected to the signal path P1 and the filter 11. The high-frequency output terminal 120 is an external connection terminal connected to the signal path P2 and the filter 12. The high-frequency output terminal 130 is an external connection terminal connected to the signal path P2 and the filter 13. The high-frequency output terminal 140 is an external connection auxiliary terminal connected to the signal path P3. Note that the antenna connection terminal 100 and the high-frequency output terminals 110 to 140 do not necessarily have to be included in the high-frequency circuit 1.

[0020] Switches 21, 22, 23, and 24 configure switch circuit 200. Switch circuit 200 is an example of a first switch circuit, and has a common terminal 201 (first common terminal), terminal 202 (first terminal), 203 (second terminal), and 204 (third terminal). One end of switch 21 and one end of switch 24 are common terminal 201, and the other end of switch 21 is connected to one end of switch 22 and one end of switch 23. The other end of switch 22 is terminal 202, the other end of switch 23 is terminal 203, and the other end of switch 24 is terminal 204. According to the above connection configuration, switch circuit 200 can switch between connection and disconnection between common terminal 201 and terminal 202, can switch between connection and disconnection between common terminal 201 and terminal 203, and can switch between connection and disconnection between common terminal 201 and terminal 204.

[0021] Although the switch circuit 200 according to this embodiment is configured with four SPST (Single-Pole Single-Throw) type switches 21 to 24, the switch circuit 200 may also be configured with one SP3T (Single-Pole 3-Throw) type switch.

[0022] Signal path P1 is an example of a first signal path, and has one end connected to terminal 202 and the other end connected to high-frequency output terminal 110. Signal path P1 is capable of transmitting a received signal of band A (first band).

[0023] Signal path P2 is an example of a second signal path, and has one end connected to terminal 203 and the other end connected to high-frequency output terminals 120 and 130. Signal path P2 is capable of transmitting a received signal of band B (second band) and a received signal of band C.

[0024] Signal path P3 is an example of a third signal path, and has one end connected to terminal 204 and the other end connected to radio-frequency output terminal 140. Signal path P3 is capable of transmitting a reception signal of band D (third band). Band D includes, for example, the 1.5 GHz band. No filter is arranged in signal path P3, and signals in a frequency range other than band D can be transmitted depending on the configuration of an external circuit (for example, a filter) connected to radio-frequency output terminal 140. Note that a filter having a passband that includes the reception band of band D may be arranged in signal path P3.

[0025] Note that Band A is a band that can transmit simultaneously with Band D, and Band B and Band C are bands that can transmit simultaneously with Band D.

[0026] The filter 11 is an example of a first filter, is arranged in the signal path P1, and has a passband that includes the reception band of band A. One end of the filter 11 is connected to the terminal 202, and the other end is connected to the high-frequency output terminal 110.

[0027] Filter 12 is an example of a second filter, is disposed on signal path P2, and has a pass band that includes the receive band of band B. One end of filter 12 is connected to matching circuit 31, and the other end is connected to high-frequency output terminal 120. Filter 13 is disposed on signal path P2, and has a pass band that includes the receive band of band C. One end of filter 13 is connected to matching circuit 31, and the other end is connected to high-frequency output terminal 130. Note that filter 13 does not necessarily have to be included in high-frequency circuit 1.

[0028] Matching circuit 31 is connected between terminal 203 and filters 12 and 13. Matching circuit 31 includes at least capacitor 310. Capacitor 310 is an example of a first capacitor, and is arranged in series on signal path P2 between terminal 203 and filter 12. Note that matching circuit 31 may include at least one of an inductor and a capacitor in addition to capacitor 310.

[0029] The inductor 42 is an example of a first inductor, and is connected between the ground and a signal path P2 between the capacitor 310 and the filter 12. The inductor 41 is connected between the ground and a signal path P1 between the terminal 202 and the filter 11. Note that the inductor 41 does not necessarily have to be included in the high-frequency circuit 1.

[0030] The switch 25 constitutes a switch circuit 300. The switch circuit 300 is an example of a second switch circuit and has a terminal 301 (fourth terminal) and a terminal 302 (fifth terminal). One end of the switch 25 is the terminal 301, and the other end of the switch 25 is the terminal 302. The switch circuit 300 can switch between connection and disconnection between the terminal 301 and the terminal 302. The terminal 301 is connected to a signal path P2 between the capacitor 310 and the filter 12, and the terminal 302 is connected to a signal path P3. In this embodiment, the terminal 301 is connected to the signal path P2 between the capacitor 310 and the inductor 42, but may also be connected to the signal path P2 between the inductor 42 and the filters 12 and 13.

[0031] Although the switch circuit 300 according to this embodiment is configured with one SPST switch 25, the switch circuit 300 may be configured with a plurality of SPST switches connected in series.

[0032] In this embodiment, band A is, for example, bands B7, B39, B40, and B41 for LTE, and bands n7, n39, n40, and n41 for 5G-NR. Band B is, for example, bands B1 and B3 for LTE, and bands n1 and n3 for 5G-NR. Band C is, for example, bands B1 and B3 for LTE, and bands n1 and n3 for 5G-NR. Band D is, for example, bands B32, B75, and B76 for LTE, and bands n32, n75, and n76 for 5G-NR.

[0033] [2. High-frequency circuit 500 according to comparative example 1] Next, the circuit configuration of a high-frequency circuit 500 according to Comparative Example 1 will be described with reference to Fig. 2A. Fig. 2A is a circuit configuration diagram of the high-frequency circuit 500 according to Comparative Example 1. As shown in the figure, the high-frequency circuit 500 includes filters 11, 12, and 13, switches 21, 22, 23, and 24, signal paths P1, P2, and P3, a matching circuit 31, inductors 41 and 42, an antenna connection terminal 100, and high-frequency output terminals 110, 120, 130, and 140. The high-frequency circuit 500 according to Comparative Example 1 differs in configuration from the high-frequency circuit 1 according to the embodiment only in that the switch 25 is not provided.

[0034] In high-frequency circuit 500, when a receive signal of band A and a receive signal of band D are transmitted simultaneously, switches 21, 22, and 24 are conductive, and switch 23 is non-conductive. As a result, the receive signal of band A is transmitted through signal path P1, and the receive signal of band D is transmitted through signal path P3, allowing the receive signals of band A and band D to be transmitted with low loss.

[0035] On the other hand, when receiving signals for bands B and C and a band D are transmitted simultaneously, switches 21, 23, and 24 are conductive, and switch 22 is non-conductive. As a result, the receiving signals for bands B and C are transmitted through signal path P2, and the receiving signal for band D is transmitted through signal path P3. At this time, with signal paths P2 and P3 commonly connected to antenna connection terminal 100, matching circuit 31 matches the impedance of bands B and C, as seen from antenna connection terminal 100, to the reference impedance. However, the LC circuit formed by capacitor 310 and inductor 42 creates an attenuation pole in band D in the pass characteristics of signal path P2. As a result, the pass characteristics of signal path P2 affect the pass characteristics of signal path P3 connected to antenna connection terminal 100, deteriorating the insertion loss in band D.

[0036] In the high-frequency circuit 500 according to the first comparative example, in both cases where band D is received simultaneously with any other band and where band D is received independently, the path for transmitting the received signal of band D is limited to only the path passing through switch 24.

[0037] [3. High-frequency circuit 600 according to comparative example 2] Next, the circuit configuration of a high-frequency circuit 600 according to Comparative Example 2 will be described with reference to FIG. 2B. FIG. 2B is a circuit configuration diagram of the high-frequency circuit 600 according to Comparative Example 2. As shown in the figure, the high-frequency circuit 600 includes filters 11, 12, and 13, switches 21, 22, 23, and 24, signal paths P1, P2, and P3, a matching circuit 31, inductors 41 and 42, an antenna connection terminal 100, and high-frequency output terminals 110, 120, 130, and 140. The high-frequency circuit 600 according to Comparative Example 2 differs from the high-frequency circuit 1 according to the embodiment in that it does not include switch 25 and in the connection configuration of switch 24.

[0038] The switch 24 is connected between the high frequency output terminal 140 and a signal path P2 between the matching circuit 31 and the filter 12 .

[0039] In high-frequency circuit 600, when receive signals for bands B and C and receive signals for band D are simultaneously transmitted, switches 21, 23, and 24 are conductive, and switch 22 is non-conductive. As a result, receive signals for bands B and C are transmitted through signal path P2, and receive signals for band D are transmitted through signal path P3. At this time, with signal paths P2 and P3 commonly connected to antenna connection terminal 100 via matching circuit 31, matching circuit 31 matches the impedance of bands B and C, as seen from antenna connection terminal 100 to the reference impedance. Furthermore, because signal path P3 is connected to the connection point between capacitor 310 and inductor 42, the attenuation pole for band D, formed by the LC circuit consisting of capacitor 310 and inductor 42, does not affect signal path P3. This allows receive signals for bands B and C and band D to be transmitted with low loss.

[0040] On the other hand, when the receive signal of band A and the receive signal of band D are transmitted simultaneously, switches 21, 22, 23, and 24 are conductive. As a result, the receive signal of band A is transmitted through signal path P1, and the receive signal of band D is transmitted through matching circuit 31 and signal path P3. In this case, the receive signal of band D passes through matching circuit 31, which adjusts the own-band impedance of bands B and C, and therefore the insertion loss of band D in the pass characteristics of signal path P3 deteriorates.

[0041] In the high-frequency circuit 600 according to the second comparative example, both when band D is received simultaneously with any other band and when band D is received independently, the path for transmitting the received signal of band D is limited to only the path passing through switch 23, matching circuit 31, and switch 24.

[0042] [4. Circuit state of RF circuit 1 in each signal reception mode] Next, the circuit state of the high-frequency circuit 1 according to this embodiment in each signal reception mode will be described.

[0043] 3A is a circuit state diagram showing a first signal reception mode of the high-frequency circuit 1 according to the embodiment. The first signal reception mode is a mode in which a reception signal of band B (second band), a reception signal of band C, and a reception signal of band D (third band) are simultaneously received (band B / C / D simultaneous reception). In the first signal reception mode, as shown in FIG. 3A, switches 21, 23, and 25 are conductive, and switches 22 and 24 are non-conductive. In other words, common terminal 201 and terminal 203 are connected, common terminal 201 and terminal 204 are non-connected, common terminal 201 and terminal 202 are non-connected, and terminal 301 and terminal 302 are connected.

[0044] As a result, the received signal of band B passes through antenna connection terminal 100, switches 21 and 23, matching circuit 31, and filter 12, and reaches radio frequency output terminal 120. The received signal of band C passes through antenna connection terminal 100, switches 21 and 23, matching circuit 31, and filter 13, and reaches radio frequency output terminal 130. The received signal of band D passes through antenna connection terminal 100, switches 21 and 23, matching circuit 31, and switch 25, and reaches radio frequency output terminal 140.

[0045] In the first signal reception mode, the received signals for bands B and C are transmitted through signal path P2, and the received signals for band D are transmitted through signal path P3. At this time, with signal paths P2 and P3 commonly connected to terminal 203 via matching circuit 31, matching circuit 31 matches the impedance of bands B and C, as seen from terminal 203 toward signal path P2, to a reference impedance. Furthermore, because signal path P3 is connected to the connection point between capacitor 310 and inductor 42, the attenuation pole for band D, formed by the LC circuit consisting of capacitor 310 and inductor 42, does not affect signal path P3. As a result, in the first signal reception mode, the received signals for bands B, C, and D can be transmitted with low loss.

[0046] In the first signal reception mode, when transmitting a signal other than band D (hereinafter referred to as an other-band signal) through signal path P3, that is, when the attenuation pole of band D formed by the LC circuit configured with capacitor 310 and inductor 42 is not included in the band of the other-band signal, switches 21, 23, and 24 may be brought into a conductive state and switch 25 into a non-conductive state. As a result, the received signal of band B passes through antenna connection terminal 100, switches 21 and 23, matching circuit 31, and filter 12 to reach high-frequency output terminal 120. Meanwhile, the other-band signal passes through antenna connection terminal 100 and switch 24 to reach high-frequency output terminal 140. As a result, in the first signal reception mode, received signals of bands B and C and other-band signals can be transmitted with low loss.

[0047] 3B is a circuit state diagram showing a second signal reception mode of the high-frequency circuit 1 according to the embodiment. The second signal reception mode is a mode in which reception signals of band A (first band) and band D (third band) are received simultaneously (band A / D simultaneous reception). In the second signal reception mode, as shown in FIG. 3B, switches 21, 22, and 24 are in a conductive state, and switch 23 is in a non-conductive state. In other words, common terminal 201 and terminal 202 are connected, common terminal 201 and terminal 203 are not connected, common terminal 201 and terminal 204 are connected, and terminal 301 and terminal 302 are not connected.

[0048] As a result, the received signal of band A passes through antenna connection terminal 100, switches 21 and 22, and filter 11 to reach high-frequency output terminal 110. The received signal of band D passes through antenna connection terminal 100 and switch 24 to reach high-frequency output terminal 140.

[0049] In the second signal reception mode, the received signal for band A travels through signal path P1, and the received signal for band D travels through signal path P3. In this mode, signal paths P1 and P3 are not connected to matching circuit 31, which adjusts the local impedance of bands B and C, and the received signal for band A and band D does not pass through matching circuit 31, so the received signal for band A and band D can be transmitted with low loss.

[0050] According to the high-frequency circuit 1 of the present embodiment, in the first signal reception mode (simultaneous reception of bands B / C / D), the impedance of the received signals of bands B and C can be adjusted by the LC circuit formed by capacitor 310 and inductor 42, and by using signal path P3 that passes through switch circuit 300, it is possible to prevent the attenuation pole of band D, which is caused by the LC circuit, from being formed in signal path P3. This reduces the transmission loss of the received signals of bands B, C, and D. Furthermore, in the second signal reception mode (simultaneous reception of bands A and D), it is possible to reduce the transmission loss of the received signals of bands A and D by using signal paths P1 and P3 that pass through switch circuit 200 but not through switch circuit 300. This makes it possible to provide a high-frequency circuit 1 that can simultaneously transmit signals of multiple bands A, B, C, and D with low loss.

[0051] 3C is a circuit state diagram showing a third signal reception mode of the high-frequency circuit 1 according to the embodiment. The third signal reception mode is a mode in which reception signals of bands A, B, and C are received simultaneously (band A / B / C simultaneous reception). In the third signal reception mode, as shown in FIG. 3C, switches 21, 22, and 23 are in a conductive state, and switches 24 and 25 are in a non-conductive state. In other words, common terminal 201 and terminal 202 are connected, common terminal 201 and terminal 203 are connected, common terminal 201 and terminal 204 are not connected, and terminal 301 and terminal 302 are not connected.

[0052] As a result, the received signal of band B passes through antenna connection terminal 100, switches 21 and 23, matching circuit 31, and filter 12, and reaches radio frequency output terminal 120. The received signal of band C passes through antenna connection terminal 100, switches 21 and 23, matching circuit 31, and filter 13, and reaches radio frequency output terminal 130. The received signal of band A passes through antenna connection terminal 100, switches 21 and 22, and filter 11, and reaches radio frequency output terminal 110.

[0053] In the third signal reception mode, the received signals for band B and band C are transmitted through signal path P2, and the received signals for band A are transmitted through signal path P1. At this time, with signal paths P1 and P2 commonly connected to common terminal 201, matching circuit 31 matches the impedance of bands B and C, as seen from common terminal 201 toward signal path P2, to the reference impedance. Furthermore, the attenuation pole for band D, formed by the LC circuit consisting of capacitor 310 and inductor 42, does not affect the band A. As a result, in the third signal reception mode, the received signals for bands A, B, and C can be transmitted with low loss.

[0054] 3D is a circuit state diagram showing a fourth signal reception mode of the high-frequency circuit 1 according to the embodiment. The fourth signal reception mode is a mode in which signals of bands A, B, C, and D are simultaneously received (band A / B / C / D simultaneous reception). In the fourth signal reception mode, as shown in FIG. 3D, switches 21, 22, 23, and 25 are conductive, and switch 24 is non-conductive. In other words, common terminal 201 and terminal 202 are connected, common terminal 201 and terminal 203 are connected, common terminal 201 and terminal 204 are not connected, and terminal 301 and terminal 302 are connected.

[0055] As a result, the received signal of band B passes through antenna connection terminal 100, switches 21 and 23, matching circuit 31, and filter 12 to reach radio frequency output terminal 120. The received signal of band C passes through antenna connection terminal 100, switches 21 and 23, matching circuit 31, and filter 13 to reach radio frequency output terminal 130. The received signal of band A passes through antenna connection terminal 100, switches 21 and 22, and filter 11 to reach radio frequency output terminal 110. The received signal of band D passes through antenna connection terminal 100, switches 21 and 23, matching circuit 31, and switch 25 to reach radio frequency output terminal 140.

[0056] In the fourth signal reception mode, the received signal for band B and the received signal for band C travel along signal path P2, the received signal for band A travels along signal path P1, and the received signal for band D travels along signal path P3. With signal paths P1, P2, and P3 connected in common to common terminal 201, matching circuit 31 matches the impedance of bands B and C, as seen from common terminal 201 through signal path P2, to a reference impedance. The attenuation pole for band D, formed by the LC circuit configured with capacitor 310 and inductor 42, does not affect band A. Since signal path P3 is connected to the connection point between capacitor 310 and inductor 42, the attenuation pole for band D, formed by the LC circuit configured with capacitor 310 and inductor 42, does not affect signal path P3. This allows received signals for bands A, B, C, and D to be transmitted with low loss in the fourth signal reception mode.

[0057] 3E is a circuit state diagram showing a fifth signal reception mode of the high-frequency circuit 1 according to the embodiment. The fifth signal reception mode is a mode in which only reception signals of band D among bands A, B, C, and D are received (band D reception). In the fifth signal reception mode, as shown in FIG. 3E, switches 21, 22, 23, and 25 are non-conductive, and switch 24 is conductive. In other words, common terminal 201 and terminal 202 are not connected, common terminal 201 and terminal 203 are not connected, common terminal 201 and terminal 204 are connected, and terminal 301 and terminal 302 are not connected.

[0058] As a result, the received signal of band D passes through antenna connection terminal 100 and switch 24 and reaches high frequency output terminal 140 .

[0059] In the fifth signal reception mode, the reception signal of band D is transmitted through signal path P3. At this time, signal path P3 is not connected to matching circuit 31, which adjusts the own-band impedance of bands B and C, and the reception signal of band D does not pass through matching circuit 31, so the reception signal of band D can be transmitted with low loss. Furthermore, in this mode, signal path P3 can transmit signals of any frequency, not just band D, with low loss.

[0060] [5. Circuit Configuration of High-Frequency Circuit 1A According to Modification 1] Next, the circuit configuration of a high-frequency circuit 1A according to Modification 1 will be described. FIG. 4 is a circuit configuration diagram of the high-frequency circuit 1A according to Modification 1 of the embodiment. As shown in the figure, the high-frequency circuit 1A according to this modification includes filters 12, 13, and 15, switches 22, 23, 24, 25, and 28, signal paths P1, P2, and P3, matching circuits 31 and 32, inductors 41 and 42, an antenna connection terminal 100, and high-frequency output terminals 120, 130, 140, and 150. The high-frequency circuit 1A according to this modification differs from the high-frequency circuit 1 according to the embodiment in that a matching circuit 32 is arranged in the signal path P1 and a switch 28 is arranged between the signal path P1 and the signal path P3. In the following, the high-frequency circuit 1A according to this modification will be described mainly with reference to the different configurations, and a description of the same configurations as those of the high-frequency circuit 1 according to the embodiment will be omitted.

[0061] The high frequency output terminal 150 is an external connection terminal connected to the signal path P1 and the filter 15.

[0062] Switches 22, 23, and 24 configure switch circuit 200A. Switch circuit 200A is an example of a first switch circuit, and has a common terminal 201 (first common terminal), terminal 202 (first terminal), 203 (second terminal), and 204 (third terminal). One end of switch 22, one end of switch 23, and one end of switch 24 are common terminal 201, the other end of switch 22 is terminal 202, the other end of switch 23 is terminal 203, and the other end of switch 24 is terminal 204. According to the above connection configuration, switch circuit 200A can switch between connection and disconnection of common terminal 201 and terminal 202, can switch between connection and disconnection of common terminal 201 and terminal 203, and can switch between connection and disconnection of common terminal 201 and terminal 204.

[0063] Signal path P1 is an example of a first signal path, and has one end connected to terminal 202 and the other end connected to high-frequency output terminal 150. Signal path P1 is capable of transmitting a received signal of band E (first band).

[0064] Signal path P2 is an example of a second signal path, and has one end connected to terminal 203 and the other end connected to high-frequency output terminals 120 and 130. Signal path P2 is capable of transmitting a received signal of band B (second band) and a received signal of band C.

[0065] Signal path P3 is an example of a third signal path, and has one end connected to terminal 204 and the other end connected to high-frequency output terminal 140. Signal path P3 is capable of transmitting a received signal of band D (third band).

[0066] Note that Band E is a band that can transmit simultaneously with Band D, and Bands B and C are bands that can transmit simultaneously with Band D.

[0067] The filter 15 is an example of a first filter, is arranged in the signal path P1, and has a passband that includes the reception band of band E. One end of the filter 15 is connected to the matching circuit 32, and the other end is connected to the high-frequency output terminal 150.

[0068] The matching circuit 32 is connected between the terminal 202 and the filter 15. The matching circuit 32 includes at least a capacitor 320. The capacitor 320 is an example of a second capacitor, and is arranged in series on the signal path P1 between the terminal 202 and the filter 15. Note that the matching circuit 32 may include at least one of an inductor and a capacitor in addition to the capacitor 320.

[0069] The inductor 41 is an example of a second inductor, and is connected between the signal path P1 between the capacitor 320 and the filter 15 and the ground.

[0070] The switch 28 configures a switch circuit 330. The switch circuit 330 is an example of a third switch circuit, and has a terminal 331 (sixth terminal) and a terminal 332 (seventh terminal). One end of the switch 28 is the terminal 331, and the other end of the switch 28 is the terminal 332. The switch circuit 330 can switch between connection and disconnection between the terminal 331 and the terminal 332. The terminal 331 is connected to a signal path P1 between the capacitor 320 and the filter 15, and the terminal 332 is connected to a signal path P3. In this modification, the terminal 331 is connected to the signal path P1 between the capacitor 320 and the inductor 41, but may also be connected to the signal path P1 between the inductor 41 and the filter 15.

[0071] In the high-frequency circuit 1A according to this modification, in a mode in which the reception signals of band E and band D are received simultaneously (band E / D simultaneous reception), switches 22 and 28 are in a conductive state, and switches 23, 24, and 25 are in a non-conductive state. In other words, common terminal 201 and terminal 202 are connected, common terminal 201 and terminal 203 are not connected, common terminal 201 and terminal 204 are not connected, and terminal 331 and terminal 332 are connected.

[0072] As a result, the received signal of band E passes through antenna connection terminal 100, switch 22, matching circuit 32, and filter 15 to reach radio frequency output terminal 150. The received signal of band D passes through antenna connection terminal 100, switch 22, matching circuit 32, and switch 28 to reach radio frequency output terminal 140.

[0073] In a mode in which the received signals of bands E and D are received simultaneously, the received signal of band E travels through signal path P1, and the received signal of band D travels through signal path P3. At this time, with signal paths P1 and P3 commonly connected to common terminal 201 via matching circuit 32, matching circuit 32 matches the impedance of band E, as seen from common terminal 201 toward signal path P1, to a reference impedance. Furthermore, because signal path P3 is connected to the connection point between capacitor 320 and inductor 41, the attenuation pole of band E, formed by the LC circuit consisting of capacitor 320 and inductor 41, does not affect signal path P3. As a result, in the above mode, the received signals of bands E and D can be transmitted with low loss.

[0074] According to the high-frequency circuit 1A of this modification, in the first signal reception mode (simultaneous reception of bands B / C / D), the LC circuit formed by the capacitor 310 and the inductor 42 can adjust the impedance of the received signal of band B and band C in its own band, and by using the signal path P3 that passes through the switch circuit 300, it is possible to prevent the attenuation pole of band D, which is caused by the LC circuit, from being formed in the signal path P3. This reduces the transmission loss of the received signals of bands B, C, and D. Furthermore, in the second signal reception mode (simultaneous reception of bands E / D), the LC circuit formed by the capacitor 320 and the inductor 41 can adjust the impedance of the received signal of band E in its own band, and by using the signal path P3 that passes through the switch circuit 330, it is possible to prevent the attenuation pole of band D, which is caused by the LC circuit, from being formed in the signal path P3. This makes it possible to provide a high-frequency circuit 1A that can simultaneously transmit signals of multiple bands E, B, C, and D with low loss.

[0075] In this modification, band E is, for example, bands B7, B39, B40, and B41 for LTE, and bands n7, n39, n40, and n41 for 5G-NR. Band B is, for example, bands B1 and B3 for LTE, and bands n1 and n3 for 5G-NR. Band C is, for example, bands B1 and B3 for LTE, and bands n1 and n3 for 5G-NR. Band D is, for example, bands B32, B75, and B76 for LTE, and bands n32, n75, and n76 for 5G-NR.

[0076] [6. Circuit Configuration of High-Frequency Circuit 1B According to Modification 2] Next, the circuit configuration of a high-frequency circuit 1B according to Modification 2 will be described. FIG. 5 is a circuit configuration diagram of the high-frequency circuit 1B according to Modification 2 of the embodiment. As shown in the figure, the high-frequency circuit 1B according to this modification includes filters 12, 13, and 16, switches 23, 25, 26, 27, and 29, signal paths P1, P2, and P3, a matching circuit 31, inductors 41 and 42, an antenna connection terminal 100, and high-frequency output terminals 120, 130, 140, and 160. The high-frequency circuit 1B according to this modification differs from the high-frequency circuit 1 according to the embodiment mainly in that switch circuits are arranged in multiple stages between the antenna connection terminal 100 and the signal paths P1 and P3. In the following, the high-frequency circuit 1B according to this modification will be described mainly with reference to the different configurations, and a description of the same configurations as those of the high-frequency circuit 1 according to the embodiment will be omitted.

[0077] The high frequency output terminal 160 is an external connection terminal connected to the signal path P1 and the filter 16.

[0078] Switches 23 and 26 configure switch circuit 200B. Switch circuit 200B is an example of a first switch circuit, and has a common terminal 201 (first common terminal), and terminals 203 (second terminal) and 206 (first terminal and third terminal). One end of switch 23 and one end of switch 26 are common terminal 201, the other end of switch 23 is terminal 203, and the other end of switch 26 is terminal 206. According to the above connection configuration, switch circuit 200B can switch between connection and disconnection between common terminal 201 and terminal 203, and can switch between connection and disconnection between common terminal 201 and terminal 206.

[0079] Signal path P1 is an example of a first signal path, and has one end connected to terminal 206 and the other end connected to high-frequency output terminal 160. Signal path P1 is capable of transmitting a received signal of band F (first band).

[0080] Signal path P2 is an example of a second signal path, and has one end connected to terminal 203 and the other end connected to high-frequency output terminals 120 and 130. Signal path P2 is capable of transmitting a received signal of band B (second band) and a received signal of band C.

[0081] Signal path P3 is an example of a third signal path, and has one end connected to terminal 206 and the other end connected to high-frequency output terminal 140. Signal path P3 is capable of transmitting a received signal of band D (third band).

[0082] Note that band F is a band that can transmit simultaneously with band D, and bands B and C are bands that can transmit simultaneously with band D.

[0083] In this modification, the first terminal of the first switch circuit (switch circuit 200B) to which the signal path P1 is connected and the third terminal of the first switch circuit (switch circuit 200B) to which the signal path P3 is connected are the same terminal 206.

[0084] The filter 16 is an example of a first filter, is arranged in the signal path P1, and has a passband that includes the reception band of the band F. One end of the filter 16 is connected to the switch 29, and the other end is connected to the high-frequency output terminal 160.

[0085] Inductor 41 is connected between signal path P1 between switch 29 and filter 16 and ground.

[0086] The switch 27 configures a switch circuit 410. The switch circuit 410 is an example of a fourth switch circuit, and is disposed on a signal path P3 between the terminal 206 and the terminal 302 of the switch circuit 300, and is capable of switching between connection and disconnection between the terminal 206 and the terminal 302.

[0087] The switch 29 configures a switch circuit 420. The switch circuit 420 is an example of a fifth switch circuit, and is disposed in a signal path P1 between the terminal 206 and the filter 16, and is capable of switching between connection and disconnection between the terminal 206 and the filter 16.

[0088] According to the high-frequency circuit 1B of this modification, in the first signal reception mode (simultaneous reception of bands B / C / D), switches 23 and 25 are conductive, and switches 26, 27, and 29 are non-conductive. This allows the LC circuit formed by capacitor 310 and inductor 42 to adjust the impedance of the received signals of bands B and C in their own bands. Furthermore, by using signal path P3 that passes through switch circuit 300 (switch 25), it is possible to prevent the formation of an attenuation pole for band D in signal path P3 due to the LC circuit. This reduces transmission loss of received signals of bands B, C, and D. Furthermore, in the second signal reception mode (simultaneous reception of bands F / D), switches 26, 27, and 29 are conductive, and switches 23 and 25 are non-conductive. This reduces transmission loss of received signals of bands F and D by using signal paths P1 and P3 that pass through switch circuit 200B but not through switch circuit 300 (switch 25). Therefore, it is possible to provide a high frequency circuit 1B that can simultaneously transmit signals of a plurality of bands F, B, C, and D with low loss.

[0089] Furthermore, switch circuits 200B and 420 connected in series are arranged between the antenna connection terminal 100 and the signal path P1, and switch circuits 200B and 410 connected in series are arranged between the antenna connection terminal 100 and the signal path P3. This makes it possible to improve the power resistance (and breakdown resistance) of the signal paths P1 and P3.

[0090] In this modification, band F is, for example, band B7, B39, B40, or B41 for LTE, or band n7, n39, n40, or n41 for 5G-NR. Band B is, for example, band B1 or B3 for LTE, or band n1 or n3 for 5G-NR. Band C is, for example, band B1 or B3 for LTE, or band n1 or n3 for 5G-NR. Band D is, for example, band B32, B75, or B76 for LTE, or band n32, n75, or n76 for 5G-NR.

[0091] [7 Circuit Configuration of High-Frequency Circuit 1C According to Modification 3] Next, the circuit configuration of a high-frequency circuit 1C according to Modification 3 will be described. FIG. 6 is a circuit configuration diagram of the high-frequency circuit 1C according to Modification 3 of the embodiment. As shown in the figure, the high-frequency circuit 1C according to this modification includes filters 12, 13, and 15, switches 21, 23, 24, 25, 29, and 55, signal paths P1, P2, and P3, matching circuits 31, 32, and 34, inductors 42 and 43, an antenna connection terminal 100, and high-frequency output terminals 120, 130, 140, and 150. The high-frequency circuit 1C according to this modification differs from the high-frequency circuit 1 according to the embodiment in the arrangement of the matching circuits and switches. In the following, the high-frequency circuit 1C according to this modification will be described mainly with reference to the different configurations, and a description of the same configurations as those of the high-frequency circuit 1 according to the embodiment will be omitted.

[0092] The high frequency output terminal 150 is an external connection terminal connected to the signal path P1 and the filter 15.

[0093] The switches 21 and 24 configure a switch circuit 200C. The switch circuit 200C is an example of a first switch circuit, and has a common terminal 201 (first common terminal), a terminal 202 (first terminal and second terminal), and a terminal 204 (third terminal). One end of the switch 21 and one end of the switch 24 are the common terminal 201, the other end of the switch 21 is the terminal 202, and the other end of the switch 24 is the terminal 204. According to the above connection configuration, the switch circuit 200C can switch between connection and disconnection between the common terminal 201 and the terminal 202, and can switch between connection and disconnection between the common terminal 201 and the terminal 204.

[0094] The signal path P1 is an example of a first signal path, and has one end connected to the terminal 202 via the matching circuit 34 and the other end connected to the high-frequency output terminal 150. The signal path P1 is capable of transmitting a received signal of band E (first band).

[0095] Signal path P2 is an example of a second signal path, and has one end connected to terminal 202 via matching circuit 34 and the other end connected to high-frequency output terminals 120 and 130. Signal path P2 is capable of transmitting a received signal of band B (second band) and a received signal of band C.

[0096] Signal path P3 is an example of a third signal path, and has one end connected to terminal 204 and the other end connected to high-frequency output terminal 140. Signal path P3 is capable of transmitting a received signal of band D (third band).

[0097] In this modification, the first terminal of the first switch circuit (switch circuit 200C) to which the signal path P1 is connected and the second terminal of the first switch circuit (switch circuit 200C) to which the signal path P2 is connected are the same terminal 202.

[0098] Note that Band E is a band that can transmit simultaneously with Band D, and Bands B and C are bands that can transmit simultaneously with Band D.

[0099] The filter 15 is an example of a first filter, is arranged in the signal path P1, and has a passband that includes the reception band of band E. One end of the filter 15 is connected to the matching circuit 32, and the other end is connected to the high-frequency output terminal 150.

[0100] Matching circuit 32 is connected between switch 29 and filter 15. Matching circuit 32 includes at least a capacitor 320. Capacitor 320 is arranged in series in signal path P1 between switch 29 and filter 15. Matching circuit 34 is connected between terminal 202 and switches 23, 29, and 55. Matching circuit 34 includes at least a capacitor 340.

[0101] Inductor 43 is connected between signal path P1 between capacitor 320 and filter 15 and ground.

[0102] Switch 23 is disposed in signal path P2 between matching circuits 34 and 31 and is capable of switching between connection and disconnection of matching circuit 34 and signal path P2. Switch 29 is disposed in signal path P1 between matching circuits 34 and 32 and is capable of switching between connection and disconnection of matching circuit 34 and signal path P1. Switch 55 is disposed between matching circuit 34 and signal path P3 and is capable of switching between connection and disconnection of matching circuit 34 and signal path P3.

[0103] According to the high-frequency circuit 1C of this modification, in the first signal reception mode (simultaneous reception of bands B / C / D), the impedance of the received signals of bands B and C can be adjusted by the LC circuit formed by capacitor 310 and inductor 42, and by using signal path P3 that passes through switch 25, it is possible to prevent the attenuation pole of band D, which is caused by the LC circuit, from being formed in signal path P3. This reduces the transmission loss of the received signals of bands B, C, and D. Furthermore, in the second signal reception mode (simultaneous reception of bands E / D), it is possible to reduce the transmission loss of the received signals of bands E and D by using signal paths P1 and P3 that do not pass through switch 25. This makes it possible to provide a high-frequency circuit 1C that can simultaneously transmit signals of multiple bands E, B, C, and D with low loss.

[0104] In this modification, band E is, for example, bands B7, B39, B40, and B41 for LTE, and bands n7, n39, n40, and n41 for 5G-NR. Band B is, for example, bands B1 and B3 for LTE, and bands n1 and n3 for 5G-NR. Band C is, for example, bands B1 and B3 for LTE, and bands n1 and n3 for 5G-NR. Band D is, for example, bands B32, B75, and B76 for LTE, and bands n32, n75, and n76 for 5G-NR.

[0105] [8 Circuit Configuration of High-Frequency Circuit 1D According to Modification 4] Next, the circuit configuration of a high-frequency circuit 1D according to Modification 4 will be described. FIG. 7 is a circuit configuration diagram of the high-frequency circuit 1D according to Modification 4 of the embodiment. As shown in the figure, the high-frequency circuit 1D according to this modification includes filters 12, 13, 15, 16, 17, and 19, switch circuits 200D and 430, a switch 25, signal paths P1, P2, and P3, a matching circuit 31, an inductor 42, antenna connection terminals 101 and 102, and high-frequency output terminals 120, 130, 140, 150, 160, 170, 180, and 190. The high-frequency circuit 1D according to this modification has different filter and switch circuit configurations compared to the high-frequency circuit 1 according to the embodiment. Below, a description of the same configuration as the high-frequency circuit 1 according to the embodiment will be omitted, and the different configurations will be mainly described.

[0106] Antenna connection terminal 101 is an example of a first antenna connection terminal and is connected to antenna 2a and common terminal 211 (first common terminal) of switch circuit 200D. Antenna connection terminal 102 is an example of a second antenna connection terminal and is connected to antenna 2b and common terminal 212 (second common terminal) of switch circuit 200D. Radio frequency output terminal 150 is an external connection terminal connected to signal path P1 and filter 15. Radio frequency output terminal 160 is an external connection terminal connected to terminal 217 of switch circuit 200D via switch circuit 430. Radio frequency output terminal 170 is an external connection terminal connected to terminal 214 of switch circuit 200D. Radio frequency output terminal 180 is an external connection terminal connected to terminal 215 of switch circuit 200D. Radio frequency output terminal 190 is an external connection terminal connected to terminal 217 of switch circuit 200D via switch circuit 430. Note that radio frequency output terminals 120 to 190 do not necessarily have to be included in radio frequency circuit 1D.

[0107] The switch circuit 200D is an example of a first switch circuit, and has common terminals 211 (first common terminal) and 212 (second common terminal), and terminals 213 (first terminal), 214, 215, 216 (second terminal), and 217 (third terminal). According to the above connection configuration, the switch circuit 200D can switch the connection between the common terminal 211 and any one of the terminals 213 to 217, and can switch the connection between the common terminal 212 and any one of the terminals 213 to 217. The switch circuit 200D is configured, for example, with a DP5T (Double-Pole 5-Throw) type switch. Note that the terminals 214 and 215 are not necessary.

[0108] The signal path P1 is an example of a first signal path, and has one end connected to the terminal 213 (first terminal) and the other end connected to the high-frequency output terminal 150. The signal path P1 is capable of transmitting, for example, a received signal of band E (first band).

[0109] Signal path P2 is an example of a second signal path, and has one end connected to terminal 216 (second terminal) and the other end connected to high-frequency output terminals 120 and 130. Signal path P2 can transmit, for example, a received signal of band B (second band) and a received signal of band C.

[0110] Signal path P3 is an example of a third signal path, and has one end connected to terminal 217 (third terminal) via switch circuit 430 and the other end connected to high-frequency output terminal 140. Signal path P3 can transmit, for example, a received signal of band D (third band). Band D includes, for example, the 1.5 GHz band.

[0111] Filter 15 is an example of a first filter, is arranged in signal path P1, and has a passband that includes the reception band of band E (first band). Band E is, for example, band B40 for LTE or band n40 for 5G-NR. One end of filter 15 is connected to terminal 213, and the other end is connected to radio-frequency output terminal 150.

[0112] Filter 12 is an example of a second filter, is disposed on signal path P2, and has a passband that includes the reception band of band B (second band). Band B is, for example, band B1 for LTE or band n1 for 5G-NR. One end of filter 12 is connected to matching circuit 31, and the other end is connected to high-frequency output terminal 120. Filter 13 is disposed on signal path P2 and has a passband that includes the reception band of band C. Band C is, for example, band B3 for LTE or band n3 for 5G-NR. Note that filter 13 does not necessarily have to be included in high-frequency circuit 1D.

[0113] Filter 17 has a passband that includes the receive band of band B39 for LTE or band n39 for 5G-NR. One end of filter 17 is connected to terminal 214, and the other end is connected to radio-frequency output terminal 170. Filter 16 has a passband that includes the receive band of band B41 for LTE or band n41 for 5G-NR. One end of filter 16 is connected to switch 58, and the other end is connected to radio-frequency output terminal 160. Filter 19 has a passband that includes the receive band of band B7 for LTE or band n7 for 5G-NR. One end of filter 19 is connected to switch 57, and the other end is connected to radio-frequency output terminal 190. Note that filters 16, 17, and 19 may be omitted.

[0114] Matching circuit 31 is connected between terminal 216 and filters 12 and 13. Matching circuit 31 includes at least capacitor 310. Capacitor 310 is an example of a first capacitor, and is arranged in series on signal path P2 between terminal 216 and filter 12. Note that matching circuit 31 may include at least one of an inductor and a capacitor in addition to capacitor 310.

[0115] Inductor 42 is an example of a first inductor and is connected between signal path P2 between capacitor 310 and filter 12 and ground.

[0116] The switch 25 constitutes a second switch circuit. The second switch circuit has a fourth terminal and a fifth terminal. One end of the switch 25 is the fourth terminal, and the other end of the switch 25 is the fifth terminal. The switch 25 can switch between connecting and disconnecting the fourth terminal and the fifth terminal. The fourth terminal is connected to a signal path P2 between the capacitor 310 and the filter 12, and the fifth terminal is connected to a signal path P3.

[0117] Switch circuit 430 includes switches 56, 57, and 58. One end of switch 56 is connected to terminal 217, and the other end is connected to radio frequency output terminal 140. One end of switch 57 is connected to terminal 217, and the other end is connected to radio frequency output terminal 190 via filter 19. One end of switch 58 is connected to terminal 217, and the other end is connected to radio frequency output terminal 160 via filter 16.

[0118] In the first signal reception mode (simultaneous reception of bands B / C / D), common terminal 211 is connected to terminal 216, common terminal 212 is connected to terminal 216, and switch 25 is in a conductive state. As a result, the received signal of band B passes through antenna 2a, antenna connection terminal 101, switch circuit 200D, matching circuit 31, and filter 12 to reach high-frequency output terminal 120. The received signal of band C passes through antenna 2a, antenna connection terminal 101, switch circuit 200D, matching circuit 31, and filter 13 to reach high-frequency output terminal 130. The received signal of band D passes through antenna 2b, antenna connection terminal 102, switch circuit 200D, matching circuit 31, and switch 25 to reach high-frequency output terminal 140.

[0119] In the first signal reception mode, the received signals for bands B and C are transmitted through signal path P2, and the received signals for band D are transmitted through signal path P3. At this time, with signal paths P2 and P3 commonly connected to terminal 216 via matching circuit 31, matching circuit 31 matches the impedance of bands B and C, as seen from terminal 216, to a reference impedance. Furthermore, because signal path P3 is connected to the connection point between capacitor 310 and inductor 42, the attenuation pole for band D, formed by the LC circuit consisting of capacitor 310 and inductor 42, does not affect signal path P3. As a result, in the first signal reception mode, the received signals for bands B, C, and D can be transmitted with low loss.

[0120] In the second signal reception mode (simultaneous reception of bands E and D), common terminal 211 and terminal 213 are connected, common terminal 212 and terminal 217 are connected, and switch 56 is in a conductive state. As a result, the received signal of band E passes through antenna 2a, antenna connection terminal 101, switch circuit 200D, and filter 15 to reach high-frequency output terminal 150. Meanwhile, the received signal of band D passes through antenna 2b, antenna connection terminal 102, switch circuit 200D, and switch 56 to reach high-frequency output terminal 140.

[0121] In the second signal reception mode, the received signal for band E travels through signal path P1, and the received signal for band D travels through signal path P3. In this mode, signal paths P1 and P3 are not connected to matching circuit 31, which adjusts the self-band impedance of bands B and C, and the received signals for band E and band D do not pass through matching circuit 31, so the received signals for band E and band D can be transmitted with low loss.

[0122] The high-frequency circuit 1D according to this modification makes it possible to simultaneously transmit a plurality of signals of bands A, B, C, and D received by a plurality of antennas with low loss.

[0123] [9 Effects etc.] As described above, the high-frequency circuit 1 according to this embodiment includes: switch circuit 200 having common terminal 201 and terminals 202, 203, and 204; signal path P1 connected to terminal 202; filter 11, which is arranged on signal path P1 and has a passband that includes the receive band of band A; signal path P2 connected to terminal 203; filter 12, which is arranged on signal path P2 and has a passband that includes the receive band of band B; signal path P3, which is connected to terminal 204 and transmits a receive signal of band D that can be transmitted simultaneously with band A and band B; capacitor 310 arranged in series on signal path P2 between terminal 203 and filter 12; inductor 42 connected between signal path P2 between capacitor 310 and filter 12 and ground; and switch circuit 300 having terminals 301 and 302, with terminal 301 connected to signal path P2 between capacitor 310 and filter 12 and terminal 302 connected to signal path P3.

[0124] According to this, in the first signal reception mode (simultaneous reception of bands B / D), the impedance of the band B reception signal can be adjusted by the LC circuit formed by capacitor 310 and inductor 42, and by using signal path P3 that passes through switch circuit 300, it is possible to prevent an attenuation pole for band D caused by the LC circuit from being formed in signal path P3. This makes it possible to reduce transmission loss of reception signals for bands B and D. Furthermore, in the second signal reception mode (simultaneous reception of bands A / D), it is possible to reduce transmission loss of reception signals for bands A and D by using signal paths P1 and P3 that pass through switch circuit 200 but not through switch circuit 300. This makes it possible to provide a high-frequency circuit 1 that can simultaneously transmit signals of multiple bands A, B, and D with low loss.

[0125] Furthermore, for example, in the high-frequency circuit 1, the switch circuit 200 can switch between connecting and disconnecting the common terminal 201 and the terminal 202, can switch between connecting and disconnecting the common terminal 201 and the terminal 203, and can switch between connecting and disconnecting the common terminal 201 and the terminal 204, and the switch circuit 300 can switch between connecting and disconnecting the terminal 301 and the terminal 302, and when a received signal of band D and a received signal of band B are simultaneously received, the common terminal 201 and the terminal 203 are connected, the common terminal 201 and the terminal 204 are disconnected, and the terminal 301 and the terminal 302 are connected, and when a received signal of band D and a received signal of band A are simultaneously received, the common terminal 201 and the terminal 202 are connected, the common terminal 201 and the terminal 204 are connected, the common terminal 201 and the terminal 203 are disconnected, and the terminal 301 and the terminal 302 are disconnected.

[0126] This makes it possible to simultaneously transmit multiple signals of bands A, B, and D with low loss in the first signal reception mode (simultaneous reception of bands B / D) and the second signal reception mode (simultaneous reception of bands A / D).

[0127] For example, in the case where the high-frequency circuit 1 simultaneously receives a received signal of band A and a received signal of band B, the common terminal 201 and the terminal 202 are connected, the common terminal 201 and the terminal 203 are connected, the common terminal 201 and the terminal 204 are not connected, and the terminal 301 and the terminal 302 are not connected.

[0128] According to this, in the third signal reception mode (simultaneous reception of bands A and B), the reception signal of band B is transmitted through signal path P2, and the reception signal of band A is transmitted through signal path P1. At this time, with signal paths P1 and P2 commonly connected to common terminal 201, matching circuit 31 matches the impedance of band B, as seen from common terminal 201 toward signal path P2, to the reference impedance. Furthermore, the attenuation pole of band D, formed by the LC circuit consisting of capacitor 310 and inductor 42, does not affect the band A. As a result, in the third signal reception mode, the reception signals of bands A and B can be transmitted with low loss.

[0129] Furthermore, for example, in the case where the high-frequency circuit 1 simultaneously receives a received signal of band A, a received signal of band B, and a received signal of band D, the common terminal 201 and the terminal 202 are connected, the common terminal 201 and the terminal 203 are connected, the common terminal 201 and the terminal 204 are not connected, and the terminal 301 and the terminal 302 are connected.

[0130] According to this, in the fourth signal reception mode (simultaneous reception of bands A / B / D), the reception signal of band B travels through signal path P2, the reception signal of band A travels through signal path P1, and the reception signal of band D travels through signal path P3. At this time, with signal paths P1, P2, and P3 connected in common to common terminal 201, matching circuit 31 matches the impedance of band B, as seen from common terminal 201 toward signal path P2, to the reference impedance. Furthermore, the attenuation pole of band D formed by the LC circuit configured with capacitor 310 and inductor 42 does not affect the band A. Furthermore, because signal path P3 is connected to the connection point between capacitor 310 and inductor 42, the attenuation pole of band D formed by the LC circuit configured with capacitor 310 and inductor 42 does not affect signal path P3. This allows reception signals of bands A, B, and D to be transmitted with low loss in the fourth signal reception mode.

[0131] For example, in the case where the high-frequency circuit 1 receives only the reception signal of band D among bands A, B, and D, the common terminal 201 and terminal 204 are connected, the common terminal 201 and terminal 202 are not connected, the common terminal 201 and terminal 203 are not connected, and the terminal 301 and terminal 302 are not connected.

[0132] According to this, in the fifth signal reception mode (band D reception), the reception signal of band D is transmitted through signal path P3. At this time, the reception signal of band D does not pass through matching circuit 31, which is used to adjust the own-band impedance of band B, so the reception signal of band D can be transmitted with low loss.

[0133] For example, the high-frequency circuit 1A according to the first modification further includes a capacitor 320 arranged in series in a signal path P1 between the terminal 202 and the filter 15, an inductor 41 connected between the signal path P1 between the capacitor 320 and the filter 15 and ground, and a switch circuit 330 having a terminal 331 and a terminal 332, with the terminal 331 connected to the signal path P1 between the capacitor 320 and the filter 15 and the terminal 332 connected to the signal path P3.

[0134] According to this, in the first signal reception mode (simultaneous reception of bands B / D), the impedance of the band B reception signal can be adjusted by the LC circuit composed of capacitor 310 and inductor 42, and by using signal path P3 that passes through switch circuit 300, it is possible to prevent an attenuation pole for band D, which is caused by the LC circuit, from being formed in signal path P3. This reduces the transmission loss of the reception signals for bands B and D. Furthermore, in the second signal reception mode (simultaneous reception of bands E / D), the impedance of the band E reception signal can be adjusted by the LC circuit composed of capacitor 320 and inductor 41, and by using signal path P3 that passes through switch circuit 330, it is possible to prevent an attenuation pole for band D, which is caused by the LC circuit, from being formed in signal path P3. This makes it possible to provide a high-frequency circuit 1A that can simultaneously transmit signals of multiple bands E, B, and D with low loss.

[0135] Furthermore, for example, in the high-frequency circuit 1A according to the first modification, the switch circuit 330 can switch between connection and disconnection of the terminal 331 and the terminal 332; when the third reception signal of band D and the second reception signal of band B are simultaneously received, the common terminal 201 and the terminal 203 are connected, the common terminal 201 and the terminal 204 are disconnected, and the terminal 301 and the terminal 302 are connected; when the third reception signal of band D and the first reception signal of band E are simultaneously received, the common terminal 201 and the terminal 202 are connected, the common terminal 201 and the terminal 204 are disconnected, and the terminal 331 and the terminal 332 are connected.

[0136] This makes it possible to simultaneously transmit multiple signals of bands E, B, and D with low loss in the first signal reception mode (simultaneous reception of bands B / D) and the second signal reception mode (simultaneous reception of bands E / D).

[0137] For example, in a high-frequency circuit 1B according to variant example 2, terminals 202 and 204 in the high-frequency circuit 1 are combined into one terminal 206, and the high-frequency circuit 1B further includes a switch circuit 410 that is arranged in a signal path P3 between terminal 206 and switch 25 (terminal 302 thereof) and switches between connection and disconnection of terminal 206 and switch 25, and a switch circuit 420 that is arranged in a signal path P1 between terminal 206 and filter 16 and switches between connection and disconnection of terminal 206 and filter 16.

[0138] According to this, the switch circuits 200B and 420 connected in series are arranged between the antenna connection terminal 100 and the signal path P1, and the switch circuits 200B and 410 connected in series are arranged between the antenna connection terminal 100 and the signal path P3. This makes it possible to improve the power resistance (and breakdown resistance) of the signal paths P1 and P3.

[0139] For example, in the high-frequency circuit 1D according to the fourth modification, the switch circuit 200D has common terminals 211 and 212, and terminals 213, 214, 215, 216 and 217, the high-frequency circuit 1D further includes antenna connection terminals 101 and 102, the common terminal 211 is connected to the antenna connection terminal 101, the common terminal 212 is connected to the antenna connection terminal 102, and the switch circuit 200D is capable of switching the connection between the common terminal 211 and any one of 213 to 217, and is capable of switching the connection between the common terminal 212 and any one of 213 to 217.

[0140] This makes it possible to simultaneously transmit multiple signals of bands A, B, and D received by multiple antennas with low loss.

[0141] For example, in the high-frequency circuits 1, 1A, 1B, 1C, and 1D, bands A, E, and F are bands B7, B39, B40, and B41 for LTE, and bands n7, n39, n40, or n41 for 5G-NR; band B is bands B1 and B3 for LTE, and bands n1 or n3 for 5G-NR; and band D is bands B32, B75, and B76 for LTE, and bands n32, n75, or n76 for 5G-NR.

[0142] (Other embodiments) Although the high-frequency circuit according to the present invention has been described above based on the embodiments and modifications thereof, the high-frequency circuit according to the present invention is not limited to the above-described embodiments and modifications. The present invention also includes other embodiments realized by combining any of the components in the above-described embodiments and modifications, modifications obtained by applying various modifications to the above-described embodiments and modifications that would occur to those skilled in the art without departing from the spirit of the present invention, and various devices incorporating the above-described high-frequency circuit.

[0143] For example, in the circuit configurations of the high-frequency circuits according to the above-described embodiments and modifications, other circuit elements, wiring, etc. may be inserted between the paths connecting the circuit elements and signal paths shown in the drawings.

[0144] In addition, although the above-described embodiments use cellular bands for 5G-NR or LTE, communication bands for other radio access technologies may be used in addition to or instead of 5G-NR or LTE. For example, communication bands for wireless local area networks may be used.

[0145] The features of the high-frequency circuits described based on the above-described embodiments and modifications will be described below.

[0146] <1> a first switch circuit having a first common terminal, a first terminal, a second terminal, and a third terminal; a first signal path connected to the first terminal; a first filter disposed in the first signal path and having a passband that includes a receive band of the first band; a second signal path connected to the second terminal; a second filter disposed in the second signal path and having a passband that includes a receive band of the second band; a third signal path connected to the third terminal and configured to transmit a reception signal of a third band that can be transmitted simultaneously with the first band and the second band; a first capacitor disposed in series in the second signal path between the second terminal and the second filter; a first inductor connected between the second signal path between the first capacitor and the second filter and ground; a second switch circuit having a fourth terminal and a fifth terminal, the fourth terminal connected to the second signal path between the first capacitor and the second filter, and the fifth terminal connected to the third signal path.

[0147] <2> The first switch circuit is a first common terminal and a first terminal that are switchable between connection and disconnection; a first common terminal and a second terminal are switchably connected and disconnected; a first common terminal and a third terminal are switchably connected and disconnected; The second switch circuit is The fourth terminal and the fifth terminal can be switched between connection and non-connection, When simultaneously receiving a reception signal of the third band and a reception signal of the second band, the first common terminal and the second terminal are connected, the first common terminal and the third terminal are not connected, and the fourth terminal and the fifth terminal are connected; When the third band reception signal and the first band reception signal are simultaneously received, the first common terminal and the first terminal are connected, the first common terminal and the third terminal are connected, the first common terminal and the second terminal are not connected, and the fourth terminal and the fifth terminal are not connected. <1> The high-frequency circuit according to claim 1.

[0148] <3> When simultaneously receiving the first band reception signal and the second band reception signal, the first common terminal and the first terminal are connected, the first common terminal and the second terminal are connected, the first common terminal and the third terminal are not connected, and the fourth terminal and the fifth terminal are not connected. <1> or <2> The high-frequency circuit according to claim 1.

[0149] <4> When the first band reception signal, the second band reception signal, and the third band reception signal are simultaneously received, the first common terminal and the first terminal are connected, the first common terminal and the second terminal are connected, the first common terminal and the third terminal are not connected, and the fourth terminal and the fifth terminal are connected. <1> ~ <3> 10. The high-frequency circuit according to claim 9,

[0150] <5> When receiving only a reception signal of the third band among the first band, the second band, and the third band, the first common terminal and the third terminal are connected, the first common terminal and the first terminal are not connected, the first common terminal and the second terminal are not connected, and the fourth terminal and the fifth terminal are not connected. <1> ~ <4> 10. The high-frequency circuit according to claim 9,

[0151] <6> moreover, a second capacitor disposed in series in the first signal path between the first terminal and the first filter; a second inductor connected between the first signal path between the second capacitor and the first filter and ground; a third switch circuit having a sixth terminal and a seventh terminal, the sixth terminal being connected to the first signal path between the second capacitor and the first filter, and the seventh terminal being connected to the third signal path; <1> The high-frequency circuit according to claim 1.

[0152] <7> The first switch circuit is a first common terminal and a first terminal that are switchable between connection and disconnection; a first common terminal and a second terminal are switchably connected and disconnected; a first common terminal and a third terminal are switchably connected and disconnected; The second switch circuit is The fourth terminal and the fifth terminal can be switched between connection and non-connection, The third switch circuit is The sixth terminal and the seventh terminal can be switched between connection and non-connection, When simultaneously receiving a third reception signal of the third band and a second reception signal of the second band, the first common terminal and the second terminal are connected, the first common terminal and the third terminal are not connected, and the fourth terminal and the fifth terminal are connected; When simultaneously receiving the third reception signal of the third band and the first reception signal of the first band, the first common terminal and the first terminal are connected, the first common terminal and the third terminal are not connected, and the sixth terminal and the seventh terminal are connected. <6> The high-frequency circuit according to claim 1.

[0153] <8> the first terminal is the same as the third terminal, The high-frequency circuit further comprises: a fourth switch circuit disposed in the third signal path between the third terminal and the fifth terminal, and configured to switch between connection and disconnection between the third terminal and the fifth terminal; a fifth switch circuit disposed in the first signal path between the first terminal and the first filter, and configured to switch between connection and disconnection between the first terminal and the first filter; <1> ~ <5> 10. The high-frequency circuit according to claim 9,

[0154] <9> the first switch circuit further has a second common terminal; the high-frequency circuit further includes a first antenna connection terminal and a second antenna connection terminal; the first common terminal is connected to the first antenna connection terminal; the second common terminal is connected to the second antenna connection terminal; The first switch circuit is a connection between the first common terminal and any one of the first terminal, the second terminal, and the third terminal can be switched; The connection between the second common terminal and any one of the first terminal, the second terminal, and the third terminal can be switched. <1> ~ <8> 10. The high-frequency circuit according to claim 9,

[0155] <10> The first band is band B7, B39, B40, or B41 for LTE, or band n7, n39, n40, or n41 for 5G-NR; The second band is band B1, B3 for LTE, or band n1 or n3 for 5G-NR; The third band is band B32, B75, or B76 for LTE, or band n32, n75, or n76 for 5G-NR. <1> ~ <9> 10. The high-frequency circuit according to claim 9, [Industrial Applicability]

[0156] The present invention can be widely used as a high-frequency circuit disposed in the front end of communication devices such as mobile phones. [Explanation of symbols]

[0157] 1, 1A, 1B, 1C, 1D, 500, 600 High frequency circuits 2, 2a, 2b antennas 11, 12, 13, 15, 16, 17, 19 Filters 21, 22, 23, 24, 25, 26, 27, 28, 29, 55, 56, 57, 58 Switches 31, 32, 34 matching circuit 41, 42, 43 Inductors 100, 101, 102 Antenna connection terminals 110, 120, 130, 140, 150, 160, 170, 180, 190 High frequency output terminal 200, 200A, 200B, 200C, 200D, 300, 330, 410, 420, 430 Switch circuit 201, 211, 212 common terminal 202, 203, 204, 206, 213, 214, 215, 216, 217, 301, 302, 331, 332 terminals 310, 320, 340 capacitors P1, P2, P3 signal path

Claims

1. a first switch circuit having a first common terminal, a first terminal, a second terminal, and a third terminal; a first signal path connected to the first terminal; a first filter disposed in the first signal path and having a passband that includes a receive band of the first band; a second signal path connected to the second terminal; a second filter disposed in the second signal path and having a passband that includes a receive band of the second band; a third signal path connected to the third terminal and configured to transmit a received signal of a third band that can be simultaneously transmitted with the first band and the second band; a first capacitor disposed in series in the second signal path between the second terminal and the second filter; a first inductor connected between the second signal path between the first capacitor and the second filter and ground; a second switch circuit having a fourth terminal and a fifth terminal, the fourth terminal connected to the second signal path between the first capacitor and the second filter, and the fifth terminal connected to the third signal path; High frequency circuits.

2. The first switch circuit a first common terminal and a first terminal that are switchable between connection and disconnection; a first common terminal and a second terminal are switchably connected and disconnected; a first common terminal and a third terminal are switchably connected and disconnected from each other; The second switch circuit is The fourth terminal and the fifth terminal can be switched between connection and non-connection, When simultaneously receiving a reception signal of the third band and a reception signal of the second band, the first common terminal and the second terminal are connected, the first common terminal and the third terminal are not connected, and the fourth terminal and the fifth terminal are connected; When the third band reception signal and the first band reception signal are simultaneously received, the first common terminal and the first terminal are connected, the first common terminal and the third terminal are connected, the first common terminal and the second terminal are not connected, and the fourth terminal and the fifth terminal are not connected. The high frequency circuit according to claim 1 .

3. When the first band reception signal and the second band reception signal are simultaneously received, the first common terminal and the first terminal are connected, the first common terminal and the second terminal are connected, the first common terminal and the third terminal are not connected, and the fourth terminal and the fifth terminal are not connected. The high frequency circuit according to claim 2.

4. When the first band reception signal, the second band reception signal, and the third band reception signal are simultaneously received, the first common terminal and the first terminal are connected, the first common terminal and the second terminal are connected, the first common terminal and the third terminal are not connected, and the fourth terminal and the fifth terminal are connected. The high frequency circuit according to claim 2.

5. When receiving only a reception signal of the third band among the first band, the second band, and the third band, the first common terminal and the third terminal are connected, the first common terminal and the first terminal are not connected, the first common terminal and the second terminal are not connected, and the fourth terminal and the fifth terminal are not connected. The high frequency circuit according to claim 2.

6. moreover, a second capacitor disposed in series in the first signal path between the first terminal and the first filter; a second inductor connected between the first signal path between the second capacitor and the first filter and ground; a third switch circuit having a sixth terminal and a seventh terminal, the sixth terminal being connected to the first signal path between the second capacitor and the first filter, and the seventh terminal being connected to the third signal path; The high frequency circuit according to claim 1 .

7. The first switch circuit a first common terminal and a first terminal that are switchable between connection and disconnection; a first common terminal and a second terminal are switchably connected and disconnected; a first common terminal and a third terminal are switchably connected and disconnected from each other; The second switch circuit is The fourth terminal and the fifth terminal can be switched between connection and non-connection, The third switch circuit is The sixth terminal and the seventh terminal can be switched between connection and non-connection, When simultaneously receiving a reception signal of the third band and a reception signal of the second band, the first common terminal and the second terminal are connected, the first common terminal and the third terminal are not connected, and the fourth terminal and the fifth terminal are connected; When the third band reception signal and the first band reception signal are simultaneously received, the first common terminal and the first terminal are connected, the first common terminal and the third terminal are not connected, and the sixth terminal and the seventh terminal are connected. The high frequency circuit according to claim 6.

8. the first terminal is the same as the third terminal, The high-frequency circuit further comprises: a fourth switch circuit disposed in the third signal path between the third terminal and the fifth terminal, and configured to switch between connection and disconnection between the third terminal and the fifth terminal; a fifth switch circuit disposed in the first signal path between the first terminal and the first filter, and configured to switch between connection and disconnection between the first terminal and the first filter; The high frequency circuit according to claim 1 .

9. the first switch circuit further has a second common terminal; the high-frequency circuit further includes a first antenna connection terminal and a second antenna connection terminal; the first common terminal is connected to the first antenna connection terminal; the second common terminal is connected to the second antenna connection terminal; The first switch circuit a connection between the first common terminal and any one of the first terminal, the second terminal, and the third terminal can be switched; a connection between the second common terminal and any one of the first terminal, the second terminal, and the third terminal can be switched; The high-frequency circuit according to any one of claims 1 to 8.

10. The first band is band B7, B39, B40, or B41 for LTE, or band n7, n39, n40, or n41 for 5G-NR; The second band is band B1, B3 for LTE, band n1 or n3 for 5G-NR, The third band is band B32, B75, or B76 for LTE, or band n32, n75, or n76 for 5G-NR; The high-frequency circuit according to any one of claims 1 to 8.

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