Amplifier circuit

Abstract

This amplifier circuit (10) comprises: 90° hybrid circuits (51 and 52) having output terminals (51b and 51c); power amplifiers (21, 22 and 23); switches (41), (42); and a synthesis circuit (30) having input terminals (30a and 30b). The output terminal (51b) is connected to a selection terminal (41b), the output terminal (51c) is connected to an input terminal of the power amplifier (22), an output terminal (52b) is connected to a selection terminal (41c), an output terminal (52c) is connected to an input terminal of the power amplifier (23), a common terminal (41a) is connected to an input terminal of the power amplifier (21), an output terminal of the power amplifier (21) is connected to the input terminal (30a), an output terminal of the power amplifier (22) is connected to a selection terminal (42b), an output terminal of the power amplifier (23) is connected to a selection terminal (42c), and a common terminal (42a) is connected to the input terminal (30b).

Description

Amplification circuit

[0001] The present invention relates to an amplifier circuit.

[0002] Patent Document 1 discloses a multi-band radio frequency module (amplifier circuit) including a first power amplifier for amplifying a transmission signal in a first frequency band and a second power amplifier for amplifying a transmission signal in a second frequency band. Each of the first power amplifier and the second power amplifier is a differential amplifier, and each is composed of two amplifying elements with different phases.

[0003] Japanese Patent Application Laid-Open No. 2021-158569

[0004] However, in the amplifier circuit disclosed in Patent Document 1, two amplifier elements are arranged for each band, and therefore the more bands in the multi-band configuration the more difficult it is to reduce the size of the amplifier circuit.

[0005] The present invention has been made to solve the above-mentioned problems, and has an object to provide a miniaturized multi-band compatible amplifier circuit.

[0006] In order to achieve the above object, an amplifier circuit according to one aspect of the present invention includes a first 90° hybrid circuit having a first input terminal, a first output terminal, and a second output terminal; a second 90° hybrid circuit having a second input terminal, a third output terminal, and a fourth output terminal; a first power amplifier, a second power amplifier, and a third power amplifier; a first switch having a first common terminal, a first selection terminal, and a second selection terminal; a second switch having a second common terminal, a third selection terminal, and a fourth selection terminal; and a combining circuit having a fifth output terminal, wherein the first output terminal is connected to the first selection terminal, the second output terminal is connected to the input terminal of the second power amplifier, the third output terminal is connected to the second selection terminal, the fourth output terminal is connected to the input terminal of the third power amplifier, the first common terminal is connected to the input terminal of the first power amplifier, the output terminal of the first power amplifier is connected to the third input terminal, the output terminal of the second power amplifier is connected to the third selection terminal, the output terminal of the third power amplifier is connected to the fourth selection terminal, and the second common terminal is connected to the fourth input terminal.

[0007] An amplifier circuit according to one aspect of the present invention includes a first 90° hybrid circuit having a first input terminal, a first output terminal, and a second output terminal; a second 90° hybrid circuit having a second input terminal, a third output terminal, and a fourth output terminal; a first power amplifier, a second power amplifier, and a third power amplifier; a first switch having a first common terminal, a first selection terminal, and a second selection terminal; a second switch having a second common terminal, a third common terminal, a third selection terminal, a fourth selection terminal, and a fifth selection terminal; the first output terminal is connected to the first selection terminal, the second output terminal is connected to the input terminal of the second power amplifier, the third output terminal is connected to the second selection terminal, the fourth output terminal is connected to the input terminal of the third power amplifier, the first common terminal is connected to the input terminal of the first power amplifier, the output terminal of the first power amplifier is connected to the fourth selection terminal, the output terminal of the second power amplifier is connected to the third selection terminal, the output terminal of the third power amplifier is connected to the fifth selection terminal, the second common terminal is connected to the third input terminal, and the third common terminal is connected to the fourth input terminal.

[0008] According to the present invention, it is possible to provide a miniaturized multi-band compatible amplifier circuit.

[0009] FIG. 1 is a circuit configuration diagram of an amplifier circuit, a high-frequency circuit, and a communication device according to a first embodiment. FIG. 2 is a diagram illustrating an example of a circuit configuration of a low-pass filter and a high-pass filter. FIG. 3A is a diagram illustrating a circuit state of the amplifier circuit according to the first embodiment during band A transmission. FIG. 3B is a diagram illustrating a circuit state of the amplifier circuit according to the first embodiment during band B transmission. FIG. 4 is a circuit configuration diagram of an amplifier circuit according to a modified example. FIG. 5 is a circuit configuration diagram of an amplifier circuit according to a second embodiment. FIG. 6 is a circuit configuration diagram of an amplifier circuit according to a third embodiment. FIG. 7 is a circuit configuration diagram of an amplifier circuit according to a fourth embodiment. FIG. 8A is a diagram illustrating a circuit state of the amplifier circuit according to the fourth embodiment during HB transmission. FIG. 8B is a diagram illustrating a circuit state of the amplifier circuit according to the fourth embodiment during MB transmission. FIG. 9A is a diagram illustrating frequency characteristics of a high-pass filter and a power amplifier of the amplifier circuit according to the fourth embodiment during HB transmission. FIG. 9B is a diagram illustrating frequency characteristics of a high-pass filter and a power amplifier of the amplifier circuit according to the fourth embodiment during MB transmission. FIG. 10 is a plan view of the high-frequency circuit according to the first embodiment. Fig. 11 is a plan view of a high-frequency circuit according to Example 2. Fig. 12 is a plan view of a high-frequency circuit according to Example 3. Fig. 13 is a plan view of a high-frequency circuit according to Example 4.

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, arrangements and connection forms of the components shown in the following embodiments are merely examples and are not intended to limit the present invention.

[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 configuration of the present disclosure, "connected" includes not only direct connection by connection terminals and / or wiring conductors, but also electrical connection via other circuit elements. "Connected between A and B" means connected to both A and B between A and B.

[0013] In addition, in this disclosure, a planar view of a board means that the board and the circuit elements mounted on the board are viewed by orthogonal projection onto a plane parallel to the main surface of the board.

[0014] Furthermore, in the component placement of the present disclosure, "a component is placed on a substrate" includes a component being placed on the main surface of the substrate and a component being placed within the substrate. "A component is placed on the main surface of the substrate" includes a component being placed in contact with the main surface of the substrate, as well as a component being placed above the main surface without contacting the main surface (for example, a component being stacked on another component placed in contact with the main surface). "A component is placed on the main surface of the substrate" may also include a component being placed in a recess formed in the main surface. "A component is placed within the substrate" includes a component being encapsulated within a module substrate, as well as a component being entirely placed between both main surfaces of the substrate but partially not covered by the substrate, and a component being only partially placed within the substrate.

[0015] In addition, in this disclosure, a "path" means a transmission line composed of a wiring through which a high-frequency signal propagates, an electrode directly connected to the wiring, and a terminal directly connected to the wiring or the electrode.

[0016] In addition, in this disclosure, "component A is arranged in series on path B" means that both the signal input terminal and the signal output terminal of component A are connected to wiring, electrodes, or terminals that make up path B.

[0017] In the present invention, the terms "terminal," "input end," and "output end" refer to the points at which conductors within elements terminate. However, if the impedance of the conductor between elements is sufficiently low, a terminal is interpreted as any point on the conductor between elements or the entire conductor, not just a single point.

[0018] Furthermore, terms indicating the relationship between elements, such as "parallel" and "perpendicular," terms indicating the shape of elements, such as "rectangle," and numerical ranges do not only represent strict meanings, but also include substantially equivalent ranges, for example, including an error of a few percent.

[0019] The "passband of a filter" is defined as the portion of the frequency spectrum transmitted by the filter over which the output power is not attenuated by more than 3 dB below the maximum output power. The upper and lower ends of the passband of a bandpass filter are therefore identified as the higher and lower frequencies of the two points at which the output power is attenuated by 3 dB below the maximum output power.

[0020] The term "transmission band" refers to a frequency band used for transmission in a communication device. The term "reception band" refers to a frequency band used for reception in a communication device. For example, in frequency division duplex (FDD), different frequency bands are used as the transmission band and the reception band, while in time division duplex (TDD), the same frequency band is used as the transmission band and the reception band. In particular, in FDD, when a communication device is implemented in a user equipment (UE) of a cellular network, an uplink operation band is used as the transmission band, and a downlink operation band is used as the reception band. Conversely, when a communication device is implemented as a base station (BS) of a cellular network, the downlink band is used as the transmission band, and the uplink band is used as the reception band.

[0021] The "passing phase" of a high frequency signal between two terminals can be obtained by applying a measurement RF probe to the two terminals and measuring the passing characteristic (S21 or S12) with a network analyzer.

[0022] In the present invention, the values ​​of the phase and passing phase of the high frequency signal do not only indicate the strict meaning, but also include a substantially equivalent range, and include a difference of, for example, about 30%.

[0023] (Embodiments) [1 Circuit Configuration of Amplifier Circuit 10, High-Frequency Circuit 1, and Communication Device 4 According to Example 1] The circuit configuration of an amplifier circuit 10, a high-frequency circuit 1, and a communication device 4 according to Example 1 will be described with reference to Fig. 1. Fig. 1 is a circuit configuration diagram of the amplifier circuit 10, the high-frequency circuit 1, and the communication device 4 according to Example 1.

[0024] [1.1 Circuit Configuration of Communication Device 4] First, a description will be given of the circuit configuration of the communication device 4. As shown in Fig. 1 , the communication device 4 according to this embodiment includes a high-frequency circuit 1, an antenna 2, and an RF signal processing circuit (RFIC: Radio Frequency Integrated Circuit) 3.

[0025] The high-frequency circuit 1 transmits high-frequency signals between the antenna 2 and the RFIC 3. The detailed circuit configuration of the high-frequency circuit 1 will be described later.

[0026] The antenna 2 is connected to the antenna connection terminal 100 of the high frequency circuit 1 and transmits the high frequency signal output from the high frequency circuit 1. The antenna 2 may also receive a high frequency signal from the outside and output it to the high frequency circuit 1.

[0027] The RFIC 3 is an example of a signal processing circuit that processes high-frequency signals. Specifically, the RFIC 3 performs signal processing on a transmission signal input from a baseband signal processing circuit (BBIC, not shown) by up-conversion or the like, and outputs the transmission signal generated by the signal processing to the transmission path of the high-frequency circuit 1. The RFIC 3 may also perform signal processing on a reception signal input via the reception path of the high-frequency circuit 1 by down-conversion or the like, and output the reception signal generated by the signal processing to the BBIC. The RFIC 3 also has a control unit that controls the high-frequency circuit 1. Note that part or all of the functions of the RFIC 3 as a control unit may be implemented outside the RFIC 3, for example, in the BBIC or the high-frequency circuit 1.

[0028] The RFIC 3 also functions as a control unit that controls the power supply voltage Vcc and bias voltage Vb supplied to each amplifier in the amplifier circuit 10. Specifically, the RFIC 3 outputs control signals to a power supply circuit (not shown) and a bias circuit (not shown). The power supply circuit and bias circuit may be disposed in the high-frequency circuit 1 or the amplifier circuit 10. Each amplifier in the amplifier circuit 10 is supplied with the power supply voltage Vcc controlled by the control signal from the power supply circuit, and with the bias voltage Vb controlled by the control signal from the bias circuit.

[0029] The RFIC 3 also functions as a control unit that controls the connections of the switches 41, 42, 43, and 44 of the high-frequency circuit 1 based on the communication band (frequency band) used.

[0030] In the communication device 4 according to this embodiment, the antenna 2 is not an essential component.

[0031] [1.2 Circuit Configuration of High-Frequency Circuit 1] Next, a description will be given of the circuit configuration of the high-frequency circuit 1. As shown in Fig. 1 , the high-frequency circuit 1 includes an amplifier circuit 10, filters 33 and 34, switches 43 and 44, and an antenna connection terminal 100.

[0032] The amplifier circuit 10 amplifies a transmission signal of band A (first band) input from a signal input terminal 110 and a transmission signal of band B (second band) input from a signal input terminal 120 .

[0033] In the present disclosure, each of band A and band B refers to a frequency band predefined by a standardization organization (e.g., 3GPP (registered trademark: 3rd Generation Partnership Project), IEEE (Institute of Electrical and Electronics Engineers), etc.) for a communication system built using radio access technology (RAT). In this embodiment, the communication system may be, for example, a 4G-LTE (Long Term Evolution) system, a 5G-NR (New Radio) system, and a WLAN (Wireless Local Area Network) system, but is not limited to these.

[0034] The filter 33 is connected between the switches 43 and 44, and passes transmission signals in the transmission band of band A among the transmission signals amplified by the amplifier circuit 10. The filter 34 is connected between the switches 43 and 44, and passes transmission signals in the transmission band of band B among the transmission signals amplified by the amplifier circuit 10.

[0035] The switch 43 has a common terminal 43a and selection terminals 43b and 43c. The common terminal 43a is connected to the signal output terminal 130 of the amplifier circuit 10, the selection terminal 43b is connected to the filter 33, and the selection terminal 43c is connected to the filter 34. In this connection configuration, the switch 43 switches between connecting and disconnecting the signal output terminal 130 and the filter 33, and between connecting and disconnecting the signal output terminal 130 and the filter 34.

[0036] The switch 44 is an example of an antenna switch, and is connected to the antenna connection terminal 100 to switch between connection and disconnection between the antenna connection terminal 100 and the filter 33, and also to switch between connection and disconnection between the antenna connection terminal 100 and the filter 34.

[0037] The high-frequency circuit 1 may include a receiving circuit for transmitting a signal received from the antenna 2 to the RFIC 3. In this case, the high-frequency circuit 1 may include a low-noise amplifier and a receiving filter.

[0038] According to the above circuit configuration, the high frequency circuit 1 can transmit a high frequency signal of either band A or band B.

[0039] [1.3 Circuit Configuration of Amplifier Circuit 10] Next, the circuit configuration of the amplifier circuit 10 will be described in detail.

[0040] As shown in FIG. 1, the amplifier circuit 10 includes amplifiers 11 and 12, power amplifiers 21, 22, and 23, a combining circuit 30, switches 41 and 42, 90° hybrid circuits 51 and 52, signal input terminals 110 and 120, and a signal output terminal 130.

[0041] The signal input terminals 110 and 120 are connected to the RFIC 3. The signal output terminal 130 is connected to the antenna connection terminal 100 via switches 43 and 44 and filters 33 and 34. Each of the signal input terminals 110, 120, the signal output terminal 130, and the antenna connection terminal 100 may be a metal conductor such as a metal electrode or a metal bump, or may be a point (node) on a metal wiring.

[0042] Amplifier 11 is an example of a preamplifier, has an input terminal connected to signal input terminal 110, and an output terminal connected to 90° hybrid circuit 51, and amplifies the high-frequency signal of band A input from signal input terminal 110. Amplifier 12 is an example of a preamplifier, has an input terminal connected to signal input terminal 120, and an output terminal connected to 90° hybrid circuit 52, and amplifies the high-frequency signal of band B input from signal input terminal 120. Amplifiers 11 and 12 do not necessarily have to be included in amplifier circuit 10.

[0043] The power amplifier 21 is an example of a first power amplifier and is capable of amplifying signals in band A and band B. The power amplifier 22 is an example of a second power amplifier and is capable of amplifying signals in band A. The power amplifier 23 is an example of a third power amplifier and is capable of amplifying signals in band B.

[0044] Each of the amplifiers 11 and 12 and the power amplifiers 21 to 23 includes an amplifying transistor. The amplifying transistor may be, for example, a bipolar transistor such as a heterojunction bipolar transistor (HBT) or a field-effect transistor such as a metal-oxide-semiconductor field-effect transistor (MOSFET). If the amplifying transistor is a bipolar transistor, the input terminals of the amplifiers 11 and 12 and the power amplifiers 21 to 23 are, for example, the base terminals of the bipolar transistors, and the output terminals of the amplifiers 11 and 12 and the power amplifiers 21 to 23 are, for example, the collector terminals of the bipolar transistors. If the amplifying transistors are field-effect transistors, the input terminals of the amplifiers 11 and 12 and the power amplifiers 21 to 23 are, for example, the gate terminals of the field-effect transistors, and the output terminals of the amplifiers 11 and 12 and the power amplifiers 21 to 23 are, for example, the drain terminals of the field-effect transistors.

[0045] The 90° hybrid circuit 51 is an example of a first 90° hybrid circuit, and has an input terminal 51 a and output terminals 51 b and 51 c, and is configured so that the phase difference between a first output signal output from the output terminal 51 b and a second output signal output from the output terminal 51 c is 90°. In this embodiment, the input terminal 51 a is an example of a first input terminal, the output terminal 51 b is an example of a first output terminal, the output terminal 51 c is an example of a second output terminal, and the second output signal output from the output terminal 51 c leads in phase by 90° relative to the first output signal output from the output terminal 51 b.

[0046] The 90° hybrid circuit 52 is an example of a second 90° hybrid circuit, and has an input terminal 52a and output terminals 52b and 52c, and is configured so that the phase difference between a third output signal output from the output terminal 52b and a fourth output signal output from the output terminal 52c is 90°. In this embodiment, the input terminal 52a is an example of a second input terminal, the output terminal 52b is an example of a third output terminal, and the output terminal 52c is an example of a fourth output terminal, and the fourth output signal output from the output terminal 52c leads the third output signal output from the output terminal 52b by 90° in phase.

[0047] The switch 41 is an example of a first switch, and has a common terminal 41 a (first common terminal), selection terminals 41 b (first selection terminal), and 41 c (second selection terminal), and is configured to switch the connection between the common terminal 41 a and the selection terminal 41 b and the connection between the common terminal 41 a and the selection terminal 41 c. The switch 41 is a switch circuit configured, for example, with an SPDT (Single Pole Double Throw) switch.

[0048] The switch 42 is an example of a second switch, and has a common terminal 42 a (second common terminal), a selection terminal 42 b (third selection terminal), and a selection terminal 42 c (fourth selection terminal), and is configured to switch the connection between the common terminal 42 a and the selection terminal 42 b and the connection between the common terminal 42 a and the selection terminal 42 c. The switch 42 is a switch circuit configured, for example, by an SPDT switch.

[0049] The synthesis circuit 30 has an input terminal 30a (third input terminal), an input terminal 30b (fourth input terminal), and a signal output terminal 130 (fifth output terminal), and is configured to synthesize a first input signal input to the input terminal 30a and a second input signal input to the input terminal 30b, and output the synthesized fifth output signal from the signal output terminal 130.

[0050] In this embodiment, the combining circuit 30 includes a high-pass filter 31 and a low-pass filter 32. The high-pass filter 31 is connected between the input terminal 30a and the signal output terminal 130. The low-pass filter 32 is connected between the input terminal 30b and the signal output terminal 130. The high-pass filter 31 attenuates signals on the lower frequency side than a predetermined frequency and transmits signals on the higher frequency side than the predetermined frequency with low loss. The high-pass filter 31 is configured to have a pass phase of +45° (the phase at the output terminal leads the phase at the input terminal by 45°). The low-pass filter 32 attenuates signals on the higher frequency side than the predetermined frequency and transmits signals on the lower frequency side than the predetermined frequency with low loss. The low-pass filter 32 is configured to have a pass phase of −45° (the phase at the output terminal lags the phase at the input terminal by 45°).

[0051] 2 is a diagram showing example circuit configurations of a low-pass filter and a high-pass filter. As shown in the figure, the low-pass filter 32 (LPF) may have, for example, any of the following configurations: (1) a configuration in which an inductor 321 is arranged in series and a capacitor 322 is connected between a series arm and ground; (2) a configuration in which the inductor 321 is arranged in series; or (3) a configuration in which the capacitor 322 is connected between a series arm and ground. The high-pass filter 31 (HPF) may have, for example, any of the following configurations: (1) a configuration in which a capacitor 311 is arranged in series and an inductor 312 is connected between the series arm and ground; (2) a configuration in which the capacitor 311 is arranged in series; or (3) a configuration in which the inductor 312 is connected between the series arm and ground.

[0052] Returning to FIG. 1, the connection configuration of the amplifier circuit 10 will be described.

[0053] The input terminal 51a is connected to the output terminal of the amplifier 11, the output terminal 51b is connected to the selection terminal 41b, and the output terminal 51c is connected to the input terminal of the power amplifier 22. The input terminal 52a is connected to the output terminal of the amplifier 12, the output terminal 52b is connected to the selection terminal 41c, and the output terminal 52c is connected to the input terminal of the power amplifier 23.

[0054] The common terminal 41a is connected to the input terminal of the power amplifier 21, the output terminal of the power amplifier 21 is connected to the input terminal 30a, the output terminal of the power amplifier 22 is connected to the selection terminal 42b, the output terminal of the power amplifier 23 is connected to the selection terminal 42c, and the common terminal 42a is connected to the input terminal 30b.

[0055] [1.4 Amplification Modes of Amplifier Circuit 10] Next, the circuit states of the amplification modes that the amplifier circuit 10 can execute will be described.

[0056] (Band A Transmission Mode) The band A transmission mode is a mode in which a band A signal is amplified and transmitted. FIG. 3A is a diagram illustrating the circuit state of the amplifier circuit 10 according to the first embodiment during band A transmission. As illustrated in FIG. 3A, when transmitting a band A signal, the common terminal 41a and the selection terminal 41b are connected, and the common terminal 42a and the selection terminal 42b are connected. The common terminal 43a and the selection terminal 43b are also connected, and the filter 33 and the antenna connection terminal 100 are connected by the switch 44. As a result, the band A signal is input to the signal input terminal 110, a first output signal with a phase of 0° is output from the output terminal 51b, and a second output signal with a phase of +90° is output from the output terminal 51c. The first output signal passes through the switch 41, is amplified by the power amplifier 21, and is input to the input terminal 30a as an input signal with a phase of 0°. It then passes through the high-pass filter 31 to become the first input signal with a phase of +45°. On the other hand, the second output signal is amplified by power amplifier 22, passes through switch 42 and is input to input terminal 30b as an input signal with a phase of +90°, and passes through low-pass filter 32 to become a second input signal with a phase of +45°. Then, at signal output terminal 130, the first input signal with a phase of +45° and the second input signal with a phase of +45° are current-combined, and the combined fifth output signal is output from signal output terminal 130.

[0057] According to this, the phase difference between the first output signal at the output terminal of the power amplifier 21 and the second output signal at the output terminal of the power amplifier 22 is 90°, and the phase difference between the first input signal and the second input signal at the signal output terminal 130 is 0°, so that the amplifier circuit 10 can operate as a current-combining type balanced amplifier that is resistant to load fluctuations.

[0058] (Band B Transmission Mode) The Band B transmission mode is a mode in which a Band B signal is amplified and transmitted. FIG. 3B is a diagram showing the circuit state of the amplifier circuit 10 according to the first embodiment when a Band B signal is transmitted. As shown in FIG. 3B, when a Band B signal is transmitted, the common terminal 41a is connected to the selection terminal 41c, and the common terminal 42a is connected to the selection terminal 42c. The common terminal 43a is connected to the selection terminal 43c, and the filter 34 is connected to the antenna connection terminal 100 by the switch 44. As a result, the Band B signal is input to the signal input terminal 120, a third output signal having a phase of 0° is output from the output terminal 52b, and a fourth output signal having a phase of +90° is output from the output terminal 52c. The third output signal passes through the switch 41, is amplified by the power amplifier 21, and is input to the input terminal 30a as an input signal having a phase of 0°. It then passes through the high-pass filter 31 to become the first input signal having a phase of +45°. On the other hand, the fourth output signal is amplified by power amplifier 23, passes through switch 42 and is input to input terminal 30b as an input signal with a phase of +90°, and passes through low-pass filter 32 to become a second input signal with a phase of +45°. Then, at signal output terminal 130, the first input signal with a phase of +45° and the second input signal with a phase of +45° are current-combined, and the combined fifth output signal is output from signal output terminal 130.

[0059] According to this, the phase difference between the third output signal at the output terminal of the power amplifier 21 and the fourth output signal at the output terminal of the power amplifier 23 is 90°, and the phase difference between the first input signal and the second input signal at the signal output terminal 130 is 0°, so that the amplifier circuit 10 can operate as a current-combining type balanced amplifier that is resistant to load fluctuations.

[0060] Furthermore, the power amplifier 21, the high-pass filter 31, and the low-pass filter 32 are shared between the band A transmission mode and the band B transmission mode. This makes it possible to provide a multi-band compatible amplifier circuit 10 that is smaller in size than a conventional current-combining type balanced amplifier that has two power amplifiers, a high-pass filter, and a low-pass filter for the band A transmission mode, and two power amplifiers, a high-pass filter, and a low-pass filter for the band B transmission mode.

[0061] [1.5 Circuit Configuration of Amplifier Circuit 10A According to Modification] Next, the circuit configuration of the amplifier circuit 10A according to the modification will be described. FIG. 4 is a circuit configuration diagram of the amplifier circuit 10A according to the modification. As shown in the figure, the amplifier circuit 10A includes amplifiers 11 and 12, power amplifiers 21, 22, and 23, a combining circuit 30A, switches 41 and 42, 90° hybrid circuits 51 and 52, signal input terminals 110 and 120, and a signal output terminal 130. The amplifier circuit 10A according to this modification differs from the amplifier circuit 10 according to the first embodiment only in the configuration of the combining circuit 30A. Therefore, the following description of the amplifier circuit 10A according to this modification will omit a description of the same configuration as the amplifier circuit 10 according to the first embodiment, and will focus on the different configuration.

[0062] The 90° hybrid circuit 51 is an example of a first 90° hybrid circuit, and has an input terminal 51 a and output terminals 51 b and 51 c, and is configured so that the phase difference between a first output signal output from the output terminal 51 b and a second output signal output from the output terminal 51 c is 90°. In this modification, the input terminal 51 a is an example of a first input terminal, the output terminal 51 b is an example of a first output terminal, the output terminal 51 c is an example of a second output terminal, and the second output signal output from the output terminal 51 c leads the first output signal output from the output terminal 51 b by 90° in phase.

[0063] The 90° hybrid circuit 52 is an example of a second 90° hybrid circuit, and has an input terminal 52a and output terminals 52b and 52c, and is configured so that the phase difference between a third output signal output from the output terminal 52b and a fourth output signal output from the output terminal 52c is 90°. In this modification, the input terminal 52a is an example of a second input terminal, the output terminal 52b is an example of a third output terminal, and the output terminal 52c is an example of a fourth output terminal, and the fourth output signal output from the output terminal 52c leads the third output signal output from the output terminal 52b by 90° in phase.

[0064] The synthesis circuit 30A has an input terminal 30a (third input terminal), an input terminal 30b (fourth input terminal), and a signal output terminal 130 (fifth output terminal), and is configured to synthesize a first input signal input to the input terminal 30a and a second input signal input to the input terminal 30b, and output the synthesized fifth output signal from the signal output terminal 130.

[0065] In this modification, the combining circuit 30A includes a transformer 60, a high-pass filter 31, and a low-pass filter 32. The transformer 60 has an input coil and an output coil that are magnetically coupled to each other. The low-pass filter 32 is connected between the input terminal 30a and one end 60a of the input coil. The high-pass filter 31 is connected between the input terminal 30b and the other end 60b of the input coil. One end 60c of the output coil is connected to the signal output terminal 130, and the other end of the output coil is connected to ground.

[0066] In amplifier circuit 10A, when transmitting a band A signal, common terminal 41a is connected to selection terminal 41b, and common terminal 42a is connected to selection terminal 42b. As a result, the band A signal is input through signal input terminal 110, a first output signal with a phase of 0° is output from output terminal 51b, and a second output signal with a phase of +90° is output from output terminal 51c. The first output signal passes through switch 41, is amplified by power amplifier 21, and is input to input terminal 30a as an input signal with a phase of 0°. It then passes through low-pass filter 32 to become a first input signal with a phase of −45°. Meanwhile, the second output signal is amplified by power amplifier 22, passes through switch 42, and is input to input terminal 30b as an input signal with a phase of +90°. It then passes through high-pass filter 31 to become a second input signal with a phase of +135°. Then, the transformer 60 combines the voltages of the first input signal with a phase of −45° and the second input signal with a phase of +135°, and the combined fifth output signal is output from the signal output terminal 130 .

[0067] According to this, the phase difference between the first output signal at the output terminal of the power amplifier 21 and the second output signal at the output terminal of the power amplifier 22 is 90°, and the phase difference between the first input signal and the second input signal at the input coil of the transformer 60 is 180°, so that the amplifier circuit 10A can operate as a voltage synthesis type balanced amplifier that is resistant to load fluctuations.

[0068] Furthermore, in amplifier circuit 10A, when transmitting a band B signal, common terminal 41a is connected to selection terminal 41c, and common terminal 42a is connected to selection terminal 42c. As a result, a band B signal is input through signal input terminal 120, a third output signal with a phase of 0° is output from output terminal 52b, and a fourth output signal with a phase of +90° is output from output terminal 52c. The third output signal passes through switch 41, is amplified by power amplifier 21, and is input to input terminal 30a as an input signal with a phase of 0°. It then passes through low-pass filter 32 to become a first input signal with a phase of −45°. Meanwhile, the fourth output signal is amplified by power amplifier 23, passes through switch 42, and is input to input terminal 30b as an input signal with a phase of +90°. It then passes through high-pass filter 31 to become a second input signal with a phase of +135°. Then, the first input signal with a phase of −45° and the second input signal with a phase of +135° are voltage-combined at the signal output terminal 130 , and the combined fifth output signal is output from the signal output terminal 130 .

[0069] According to this, the phase difference between the third output signal at the output terminal of the power amplifier 21 and the fourth output signal at the output terminal of the power amplifier 23 is 90°, and the phase difference between the first input signal and the second input signal at the input coil of the transformer 60 is 180°, so that the amplifier circuit 10A can operate as a voltage synthesis type balanced amplifier that is resistant to load fluctuations.

[0070] Furthermore, the power amplifier 21, the high-pass filter 31, and the low-pass filter 32 are shared between the band A transmission mode and the band B transmission mode. This makes it possible to provide a multi-band compatible amplifier circuit 10A that is smaller in size than a conventional voltage-combining type balanced amplifier that has two power amplifiers, a high-pass filter, and a low-pass filter for the band A transmission mode, and two power amplifiers, a high-pass filter, and a low-pass filter for the band B transmission mode.

[0071] [2 Configuration of Amplifier Circuit 10B According to Second Embodiment] Next, the circuit configuration of the amplifier circuit 10B according to the second embodiment will be described. FIG. 5 is a circuit configuration diagram of the amplifier circuit 10B according to the second embodiment. As shown in the figure, the amplifier circuit 10B includes amplifiers 11 and 12, power amplifiers 21, 22, and 23, a combining circuit 30B, switches 41 and 42, 90° hybrid circuits 51 and 52, signal input terminals 110 and 120, and a signal output terminal 130. The amplifier circuit 10B according to the second embodiment differs from the amplifier circuit 10 according to the first embodiment mainly in the connection configuration of the switch 41 and the configuration of the combining circuit 30B. Therefore, in the following, the amplifier circuit 10B according to the second embodiment will be described mainly with respect to the different configurations, and a description of the same configurations as those of the amplifier circuit 10 according to the first embodiment will be omitted.

[0072] The 90° hybrid circuit 51 is an example of a first 90° hybrid circuit, and has an input terminal 51 a and output terminals 51 b and 51 c, and is configured so that the phase difference between a second output signal output from the output terminal 51 b and a first output signal output from the output terminal 51 c is 90°. In this embodiment, the input terminal 51 a is an example of a first input terminal, the output terminal 51 b is an example of a second output terminal, and the output terminal 51 c is an example of a first output terminal, and the second output signal output from the output terminal 51 b is delayed in phase by 90° from the first output signal output from the output terminal 51 c.

[0073] The 90° hybrid circuit 52 is an example of a second 90° hybrid circuit, and has an input terminal 52a and output terminals 52b and 52c, and is configured so that the phase difference between a fourth output signal output from the output terminal 52b and a third output signal output from the output terminal 52c is 90°. In this embodiment, the input terminal 52a is an example of a second input terminal, the output terminal 52b is an example of a fourth output terminal, and the output terminal 52c is an example of a third output terminal, and the fourth output signal output from the output terminal 52b lags in phase by 90° relative to the third output signal output from the output terminal 52c.

[0074] The switch 41 is an example of a first switch, and has a common terminal 41 a (first common terminal), selection terminals 41 b (first selection terminal), and 41 c (second selection terminal), and is configured to switch the connection between the common terminal 41 a and the selection terminal 41 b and the connection between the common terminal 41 a and the selection terminal 41 c. The switch 41 is a switch circuit configured, for example, by an SPDT switch.

[0075] The synthesis circuit 30B has an input terminal 30a (third input terminal), an input terminal 30b (fourth input terminal), and a signal output terminal 130 (fifth output terminal), and is configured to synthesize a first input signal input to the input terminal 30a and a second input signal input to the input terminal 30b, and output the synthesized fifth output signal from the signal output terminal 130.

[0076] In this embodiment, the synthesis circuit 30B includes a high-pass filter 31 and a low-pass filter 32. The low-pass filter 32 is connected between the input terminal 30a and the signal output terminal 130. The high-pass filter 31 is connected between the input terminal 30b and the signal output terminal 130.

[0077] The input terminal 51a is connected to the output terminal of the amplifier 11, the output terminal 51c is connected to the selection terminal 41b, and the output terminal 51b is connected to the input terminal of the power amplifier 22. The input terminal 52a is connected to the output terminal of the amplifier 12, the output terminal 52c is connected to the selection terminal 41c, and the output terminal 52b is connected to the input terminal of the power amplifier 23.

[0078] The common terminal 41a is connected to the input terminal of the power amplifier 21, the output terminal of the power amplifier 21 is connected to the input terminal 30a, the output terminal of the power amplifier 22 is connected to the selection terminal 42b, the output terminal of the power amplifier 23 is connected to the selection terminal 42c, and the common terminal 42a is connected to the input terminal 30b.

[0079] In amplifier circuit 10B, when transmitting a band A signal, common terminal 41a is connected to selection terminal 41b, and common terminal 42a is connected to selection terminal 42b. As a result, the band A signal is input through signal input terminal 110, a first output signal with a phase of +90° is output from output terminal 51c, and a second output signal with a phase of 0° is output from output terminal 51b. The first output signal passes through switch 41, is amplified by power amplifier 21, and is input to input terminal 30a as an input signal with a phase of +90°. It then passes through low-pass filter 32 to become a first input signal with a phase of +45°. Meanwhile, the second output signal is amplified by power amplifier 22, passes through switch 42, and is input to input terminal 30b as an input signal with a phase of 0°. It then passes through high-pass filter 31 to become a second input signal with a phase of +45°. Then, the first input signal with a phase of +45° and the second input signal with a phase of +45° are current-combined at the signal output terminal 130 , and the combined fifth output signal is output from the signal output terminal 130 .

[0080] According to this, in the amplifier circuit 10B, the phase difference between the first output signal at the output terminal of the power amplifier 21 and the second output signal at the output terminal of the power amplifier 22 is 90°, and the phase difference between the first input signal and the second input signal at the signal output terminal 130 is 0°, so that the amplifier circuit 10B can operate as a current-combining type balanced amplifier that is resistant to load fluctuations.

[0081] Furthermore, in amplifier circuit 10B, when transmitting a band B signal, common terminal 41a is connected to selection terminal 41c, and common terminal 42a is connected to selection terminal 42c. As a result, a band B signal is input through signal input terminal 120, a third output signal with a phase of +90° is output from output terminal 52c, and a fourth output signal with a phase of 0° is output from output terminal 52b. The third output signal passes through switch 41, is amplified by power amplifier 21, and is input to input terminal 30a as an input signal with a phase of +90°. It then passes through low-pass filter 32 to become a first input signal with a phase of +45°. Meanwhile, the fourth output signal is amplified by power amplifier 23, passes through switch 42, and is input to input terminal 30b as an input signal with a phase of 0°. It then passes through high-pass filter 31 to become a second input signal with a phase of +45°. Then, the first input signal with a phase of +45° and the second input signal with a phase of +45° are current-combined at the signal output terminal 130 , and the combined fifth output signal is output from the signal output terminal 130 .

[0082] According to this, in the amplifier circuit 10B, the phase difference between the third output signal at the output terminal of the power amplifier 21 and the fourth output signal at the output terminal of the power amplifier 23 is 90°, and the phase difference between the first input signal and the second input signal at the signal output terminal 130 is 0°, so that the amplifier circuit 10B can operate as a current-combining type balanced amplifier that is resistant to load fluctuations.

[0083] Furthermore, the power amplifier 21, the high-pass filter 31, and the low-pass filter 32 are shared between the band A transmission mode and the band B transmission mode. This makes it possible to provide a multi-band compatible amplifier circuit 10B that is smaller in size than a conventional current-combining type balanced amplifier that has two power amplifiers, a high-pass filter, and a low-pass filter for the band A transmission mode, and two power amplifiers, a high-pass filter, and a low-pass filter for the band B transmission mode.

[0084] In the amplifier circuit 10B according to the second embodiment, a voltage-combining amplifier circuit according to a modified example of the second embodiment can be realized by changing the configuration of the combining circuit 30B. Specifically, the combining circuit 30B is replaced with a combining circuit having the following configuration. The combining circuit of the amplifier circuit according to the modified example of the second embodiment includes a transformer 60, a high-pass filter 31, and a low-pass filter 32. The transformer 60 has input and output coils that are magnetically coupled to each other. The high-pass filter 31 is connected between the input terminal 30a and one end 60a of the input coil. The low-pass filter 32 is connected between the input terminal 30b and the other end 60b of the input coil. One end 60c of the output coil is connected to the signal output terminal 130, and the other end of the output coil is connected to ground.

[0085] According to this, in the amplifier circuit according to the modification of the second embodiment, in the band A transmission mode, the phase difference between the first output signal at the output end of the power amplifier 21 and the second output signal at the output end of the power amplifier 22 is 90°, and the phase difference between the first input signal and the second input signal at the input coil of the transformer 60 is 180°. Also, in the band B transmission mode, the phase difference between the third output signal at the output end of the power amplifier 21 and the fourth output signal at the output end of the power amplifier 23 is 90°, and the phase difference between the first input signal and the second input signal at the input coil of the transformer 60 is 180°. Therefore, it is possible to operate as a voltage-combining balanced amplifier that is resistant to load fluctuations.

[0086] Furthermore, the power amplifier 21, high-pass filter 31, and low-pass filter 32 are shared between the band A transmission mode and the band B transmission mode. This makes it possible to provide a miniaturized multi-band compatible amplifier circuit compared to a conventional voltage-combining type balanced amplifier that has two power amplifiers, a high-pass filter, and a low-pass filter for the band A transmission mode, and two power amplifiers, a high-pass filter, and a low-pass filter for the band B transmission mode.

[0087] [3 Configuration of Amplifier Circuit 10C According to Third Embodiment] Next, the circuit configuration of the amplifier circuit 10C according to the third embodiment will be described. FIG. 6 is a circuit configuration diagram of the amplifier circuit 10C according to the third embodiment. As shown in the figure, the amplifier circuit 10C includes amplifiers 11 and 12, power amplifiers 21, 22, and 23, a combining circuit 30C, switches 41 and 45, 90° hybrid circuits 51 and 52, signal input terminals 110 and 120, and a signal output terminal 130. The amplifier circuit 10C according to the third embodiment differs from the amplifier circuit 10 according to the first embodiment in the connection configuration of the switch 41, and the configurations of the switch 45 and the combining circuit 30C. Therefore, in the following, the same configurations as those of the amplifier circuit 10 according to the first embodiment will not be described, and the different configurations will be mainly described.

[0088] The power amplifier 21 is an example of a first power amplifier and is capable of amplifying signals in band A and band B. The power amplifier 22 is an example of a second power amplifier and is capable of amplifying signals in band A. The power amplifier 23 is an example of a third power amplifier and is capable of amplifying signals in band B.

[0089] In this embodiment, band A is, for example, a band for 4G-LTE or 5G-NR belonging to the high band group (2.4-2.8 GHz) (hereinafter, sometimes referred to as HB). Band B is, for example, a band for 4G-LTE or 5G-NR belonging to the middle band group (1.5-2.4 GHz) (hereinafter, sometimes referred to as MB). In addition, the band including band A and band B is, for example, a band for 4G-LTE or 5G-NR belonging to the middle high band group (1.5-2.8 GHz) (hereinafter, sometimes referred to as MHB).

[0090] The 90° hybrid circuit 51 is an example of a first 90° hybrid circuit, and has an input terminal 51 a and output terminals 51 b and 51 c, and is configured so that the phase difference between a second output signal output from the output terminal 51 b and a first output signal output from the output terminal 51 c is 90°. In this embodiment, the input terminal 51 a is an example of a first input terminal, the output terminal 51 b is an example of a second output terminal, and the output terminal 51 c is an example of a first output terminal, and the second output signal output from the output terminal 51 b is delayed in phase by 90° from the first output signal output from the output terminal 51 c.

[0091] The 90° hybrid circuit 52 is an example of a second 90° hybrid circuit, and has an input terminal 52a and output terminals 52b and 52c, and is configured so that the phase difference between a third output signal output from the output terminal 52b and a fourth output signal output from the output terminal 52c is 90°. In this embodiment, the input terminal 52a is an example of a second input terminal, the output terminal 52b is an example of a third output terminal, and the output terminal 52c is an example of a fourth output terminal, and the fourth output signal output from the output terminal 52c leads the third output signal output from the output terminal 52b by 90° in phase.

[0092] The switch 41 is an example of a first switch, and has a common terminal 41 a (first common terminal), selection terminals 41 b (first selection terminal), and 41 c (second selection terminal), and is configured to switch the connection between the common terminal 41 a and the selection terminal 41 b and the connection between the common terminal 41 a and the selection terminal 41 c. The switch 41 is a switch circuit configured, for example, by an SPDT switch.

[0093] The switch 45 is an example of a second switch, and has a common terminal 45a (second common terminal), 45b (third common terminal), and selection terminals 45c (third selection terminal), 45d (fourth selection terminal), and 45e (fifth selection terminal), and is configured to switch between the connection between the common terminal 45a and the selection terminal 45d and the connection between the common terminal 45b and the selection terminal 45c, and the connection between the common terminal 45a and the selection terminal 45e and the connection between the common terminal 45b and the selection terminal 45d. The switch 45 is a switch circuit configured, for example, with a DP3T (Double Pole 3 Throw) switch.

[0094] The synthesis circuit 30C has an input terminal 30a (third input terminal), an input terminal 30b (fourth input terminal), and a signal output terminal 130 (fifth output terminal), and is configured to synthesize a first input signal input to the input terminal 30a and a second input signal input to the input terminal 30b, and output the synthesized fifth output signal from the signal output terminal 130.

[0095] In this embodiment, the synthesis circuit 30C includes a high-pass filter 31 and a low-pass filter 32. The low-pass filter 32 is connected between the input terminal 30a and the signal output terminal 130. The high-pass filter 31 is connected between the input terminal 30b and the signal output terminal 130.

[0096] The input terminal 51a is connected to the output terminal of the amplifier 11, the output terminal 51c is connected to the selection terminal 41b, and the output terminal 51b is connected to the input terminal of the power amplifier 22. The input terminal 52a is connected to the output terminal of the amplifier 12, the output terminal 52b is connected to the selection terminal 41c, and the output terminal 52c is connected to the input terminal of the power amplifier 23.

[0097] The common terminal 41a is connected to the input terminal of the power amplifier 21, the output terminal of the power amplifier 21 is connected to the selection terminal 45d, the output terminal of the power amplifier 22 is connected to the selection terminal 45c, and the output terminal of the power amplifier 23 is connected to the selection terminal 45e. The common terminal 45a is connected to the input terminal 30a, and the common terminal 45b is connected to the input terminal 30b.

[0098] In amplifier circuit 10C, when transmitting a band A (HB) signal, common terminal 41a is connected to selection terminal 41b, common terminal 45a is connected to selection terminal 45d, and common terminal 45b is connected to selection terminal 45c. As a result, the band A (HB) signal is input to signal input terminal 110, a first output signal with a phase of +90° is output from output terminal 51c, and a second output signal with a phase of 0° is output from output terminal 51b. The first output signal passes through switch 41, is amplified by power amplifier 21, passes through switch 45, and is input to input terminal 30a as an input signal with a phase of +90°. It then passes through low-pass filter 32 to become a first input signal with a phase of +45°. Meanwhile, the second output signal is amplified by power amplifier 22, passes through switch 45, and is input to input terminal 30b as an input signal with a phase of 0°. It then passes through high-pass filter 31 to become a second input signal with a phase of +45°. Then, the first input signal with a phase of +45° and the second input signal with a phase of +45° are current-combined at the signal output terminal 130 , and the combined fifth output signal is output from the signal output terminal 130 .

[0099] According to this, in the amplifier circuit 10C, the phase difference between the first output signal at the output terminal of the power amplifier 21 and the second output signal at the output terminal of the power amplifier 22 is 90°, and the phase difference between the first input signal and the second input signal at the signal output terminal 130 is 0°, so that the amplifier circuit 10C can operate as a current-combining type balanced amplifier that is resistant to load fluctuations.

[0100] Furthermore, in amplifier circuit 10C, when transmitting a band B (MB) signal, common terminal 41a is connected to selection terminal 41c, common terminal 45a is connected to selection terminal 45e, and common terminal 45b is connected to selection terminal 45d. As a result, a band B (MB) signal is input through signal input terminal 120, a fourth output signal with a phase of +90° is output from output terminal 52c, and a third output signal with a phase of 0° is output from output terminal 52b. The third output signal passes through switch 41, is amplified by power amplifier 21, passes through switch 45, and is input to input terminal 30b as an input signal with a phase of 0°. It then passes through high-pass filter 31 to become a first input signal with a phase of +45°. Meanwhile, the fourth output signal is amplified by power amplifier 23, passes through switch 45, and is input to input terminal 30a as an input signal with a phase of +90°. It then passes through low-pass filter 32 to become a second input signal with a phase of +45°. Then, the first input signal with a phase of +45° and the second input signal with a phase of +45° are current-combined at the signal output terminal 130 , and the combined fifth output signal is output from the signal output terminal 130 .

[0101] According to this, in the amplifier circuit 10C, the phase difference between the third output signal at the output terminal of the power amplifier 21 and the fourth output signal at the output terminal of the power amplifier 23 is 90°, and the phase difference between the first input signal and the second input signal at the signal output terminal 130 is 0°, so that the amplifier circuit 10C can operate as a current-combining type balanced amplifier that is resistant to load fluctuations.

[0102] Furthermore, the power amplifier 21, the high-pass filter 31, and the low-pass filter 32 are shared between the band A transmission mode and the band B transmission mode. This makes it possible to provide a multi-band compatible amplifier circuit 10C that is smaller in size than a conventional current-combining type balanced amplifier that has two power amplifiers, a high-pass filter, and a low-pass filter for the band A transmission mode, and two power amplifiers, a high-pass filter, and a low-pass filter for the band B transmission mode.

[0103] Furthermore, by providing the DP3T type switch 45, it becomes possible to selectively connect each of the power amplifiers 21 to 23 to either the low-pass filter 32 or the high-pass filter 31.

[0104] In the amplifier circuit 10C according to the third embodiment, a voltage-combining amplifier circuit according to a modified example of the third embodiment can be realized by changing the configuration of the combining circuit 30C. Specifically, the combining circuit 30C is replaced with a combining circuit having the following configuration. The combining circuit of the amplifier circuit according to the modified example of the third embodiment includes a transformer 60, a high-pass filter 31, and a low-pass filter 32. The transformer 60 has input and output coils that are magnetically coupled to each other. The high-pass filter 31 is connected between the input terminal 30a and one end 60a of the input coil. The low-pass filter 32 is connected between the input terminal 30b and the other end 60b of the input coil. One end 60c of the output coil is connected to the signal output terminal 130, and the other end of the output coil is connected to ground.

[0105] According to this, in the amplifier circuit according to the modification of the third embodiment, in the band A transmission mode, the phase difference between the first output signal at the output end of the power amplifier 21 and the second output signal at the output end of the power amplifier 22 is 90°, and the phase difference between the first input signal and the second input signal at the input coil of the transformer 60 is 180°. Also, in the band B transmission mode, the phase difference between the third output signal at the output end of the power amplifier 21 and the fourth output signal at the output end of the power amplifier 23 is 90°, and the phase difference between the first input signal and the second input signal at the input coil of the transformer 60 is 180°. Therefore, it is possible to operate as a voltage-combining balanced amplifier that is resistant to load fluctuations.

[0106] Furthermore, the power amplifier 21, high-pass filter 31, and low-pass filter 32 are shared between the band A transmission mode and the band B transmission mode. This makes it possible to provide a miniaturized multi-band compatible amplifier circuit compared to a conventional voltage-combining type balanced amplifier that has two power amplifiers, a high-pass filter, and a low-pass filter for the band A transmission mode, and two power amplifiers, a high-pass filter, and a low-pass filter for the band B transmission mode.

[0107] Furthermore, by providing the DP3T type switch 45, it becomes possible to selectively connect each of the power amplifiers 21 to 23 to either the low-pass filter 32 or the high-pass filter 31.

[0108] [4 Configuration of Amplifier Circuit 10D According to Fourth Embodiment] Next, the circuit configuration of the amplifier circuit 10D according to the fourth embodiment will be described. FIG. 7 is a circuit configuration diagram of the amplifier circuit 10D according to the fourth embodiment. As shown in the figure, the amplifier circuit 10D includes amplifiers 11 and 12, power amplifiers 21, 22, and 23, a combining circuit 30D, switches 41 and 45, 90° hybrid circuits 51 and 52, signal input terminals 110 and 120, and a signal output terminal 130. The amplifier circuit 10D according to the fourth embodiment differs from the amplifier circuit 10C according to the third embodiment in the connection configuration of the switches 41 and 45 and the configuration of the combining circuit 30D. Therefore, in the following, the amplifier circuit 10D according to the fourth embodiment will be described mainly with reference to the different configurations, and a description of the same configurations as those of the amplifier circuit 10C according to the third embodiment will be omitted.

[0109] The power amplifier 21 is an example of a first power amplifier and is capable of amplifying band A and band B (MHB) (MHB signals). The power amplifier 22 is an example of a second power amplifier and is capable of amplifying band A (HB) signals. The power amplifier 23 is an example of a third power amplifier and is capable of amplifying band B (MB) signals.

[0110] The 90° hybrid circuit 51 is an example of a first 90° hybrid circuit, and has an input terminal 51 a and output terminals 51 b and 51 c, and is configured so that the phase difference between a first output signal output from the output terminal 51 b and a second output signal output from the output terminal 51 c is 90°. In this embodiment, the input terminal 51 a is an example of a first input terminal, the output terminal 51 b is an example of a first output terminal, the output terminal 51 c is an example of a second output terminal, and the second output signal output from the output terminal 51 c leads in phase by 90° relative to the first output signal output from the output terminal 51 b.

[0111] The 90° hybrid circuit 52 is an example of a second 90° hybrid circuit, and has an input terminal 52a and output terminals 52b and 52c, and is configured so that the phase difference between a fourth output signal output from the output terminal 52b and a third output signal output from the output terminal 52c is 90°. In this embodiment, the input terminal 52a is an example of a second input terminal, the output terminal 52b is an example of a fourth output terminal, and the output terminal 52c is an example of a third output terminal, and the fourth output signal output from the output terminal 52b lags in phase by 90° relative to the third output signal output from the output terminal 52c.

[0112] The synthesis circuit 30D has an input terminal 30a (third input terminal), an input terminal 30b (fourth input terminal), and a signal output terminal 130 (fifth output terminal), and is configured to synthesize a first input signal input to the input terminal 30a and a second input signal input to the input terminal 30b, and output the synthesized fifth output signal from the signal output terminal 130.

[0113] In this embodiment, the combining circuit 30D includes a high-pass filter 31 and a low-pass filter 32. The high-pass filter 31 is connected between the input terminal 30a and the signal output terminal 130. The low-pass filter 32 is connected between the input terminal 30b and the signal output terminal 130.

[0114] The input terminal 51a is connected to the output terminal of the amplifier 11, the output terminal 51b is connected to the selection terminal 41b, and the output terminal 51c is connected to the input terminal of the power amplifier 22. The input terminal 52a is connected to the output terminal of the amplifier 12, the output terminal 52c is connected to the selection terminal 41c, and the output terminal 52b is connected to the input terminal of the power amplifier 23.

[0115] The common terminal 41a is connected to the input terminal of the power amplifier 21, the output terminal of the power amplifier 21 is connected to the selection terminal 45d, the output terminal of the power amplifier 22 is connected to the selection terminal 45c, and the output terminal of the power amplifier 23 is connected to the selection terminal 45e. The common terminal 45a is connected to the input terminal 30a, and the common terminal 45b is connected to the input terminal 30b.

[0116] 8A is a diagram illustrating a circuit state of the amplifier circuit 10D according to the fourth embodiment during band A (HB) transmission. As shown in the figure, when transmitting a band A (HB) signal, the common terminal 41a and the selection terminal 41b are connected, the common terminal 45a and the selection terminal 45d are connected, and the common terminal 45b and the selection terminal 45c are connected. As a result, the band A (HB) signal is input to the signal input terminal 110, a first output signal having a phase of 0° is output from the output terminal 51b, and a second output signal having a phase of +90° is output from the output terminal 51c. The first output signal passes through the switch 41, is amplified by the power amplifier 21, passes through the switch 45, and is input to the input terminal 30a as an input signal having a phase of 0°. It then passes through the high-pass filter 31 to become the first input signal having a phase of +45°. On the other hand, the second output signal is amplified by power amplifier 22, passes through switch 45 and is input to input terminal 30b as an input signal with a phase of +90°, and passes through low-pass filter 32 to become a second input signal with a phase of +45°. Then, at signal output terminal 130, the first input signal with a phase of +45° and the second input signal with a phase of +45° are current-combined, and the combined fifth output signal is output from signal output terminal 130.

[0117] According to this, in the amplifier circuit 10D, the phase difference between the first output signal at the output terminal of the power amplifier 21 and the second output signal at the output terminal of the power amplifier 22 is 90°, and the phase difference between the first input signal and the second input signal at the signal output terminal 130 is 0°, so that the amplifier circuit 10D can operate as a current-combining type balanced amplifier that is resistant to load fluctuations.

[0118] 8B is a diagram illustrating a circuit state of the amplifier circuit 10D according to the fourth embodiment during transmission of band B (MB). As shown in FIG. 8B, when transmitting a band B (MB) signal, the common terminal 41a and the selection terminal 41c are connected, the common terminal 45a and the selection terminal 45e are connected, and the common terminal 45b and the selection terminal 45d are connected. As a result, the band B (MB) signal is input to the signal input terminal 120, a fourth output signal having a phase of 0° is output from the output terminal 52b, and a third output signal having a phase of +90° is output from the output terminal 52c. The third output signal passes through the switch 41, is amplified by the power amplifier 21, passes through the switch 45, and is input to the input terminal 30b as an input signal having a phase of +90°. It then passes through the low-pass filter 32 to become the first input signal having a phase of +45°. On the other hand, the fourth output signal is amplified by power amplifier 23, passes through switch 45 and is input to input terminal 30a as an input signal with a phase of 0°, and passes through high-pass filter 31 to become a second input signal with a phase of +45°. Then, at signal output terminal 130, the first input signal with a phase of +45° and the second input signal with a phase of +45° are current-combined, and the combined fifth output signal is output from signal output terminal 130.

[0119] According to this, in the amplifier circuit 10D, the phase difference between the third output signal at the output terminal of the power amplifier 21 and the fourth output signal at the output terminal of the power amplifier 23 is 90°, and the phase difference between the first input signal and the second input signal at the signal output terminal 130 is 0°, so that the amplifier circuit 10D can operate as a current-combining type balanced amplifier that is resistant to load fluctuations.

[0120] Furthermore, the power amplifier 21, the high-pass filter 31, and the low-pass filter 32 are shared between the band A transmission mode and the band B transmission mode. This makes it possible to provide a multi-band compatible amplifier circuit 10D that is smaller in size than a conventional current-combining type balanced amplifier that has two power amplifiers, a high-pass filter, and a low-pass filter for the band A transmission mode, and two power amplifiers, a high-pass filter, and a low-pass filter for the band B transmission mode.

[0121] Furthermore, by providing the DP3T type switch 45, it becomes possible to selectively connect each of the power amplifiers 21 to 23 to either the low-pass filter 32 or the high-pass filter 31.

[0122] 9A is a diagram showing the frequency characteristics of the high-pass filter 31 and the power amplifiers 21 and 22 during band A (HB) transmission in the amplifier circuit 10D according to Example 4. The upper part of the figure shows the pass characteristic of the high-pass filter 31, and the lower part shows the gain characteristics of the power amplifiers 21 to 23. The high-pass filter 31 includes band A (HB) and band B (MB) as passbands, but has an attenuation band on the lower frequency side of band B, so the insertion loss in band A (HB) tends to be smaller than the insertion loss in band B (MB).

[0123] 9B is a diagram showing the frequency characteristics of the low-pass filter 32 and the power amplifiers 21 and 23 during transmission in band B (MB) of the amplifier circuit 10D according to Example 4. The upper part of the figure shows the pass characteristic of the low-pass filter 32, and the lower part shows the gain characteristics of the power amplifiers 21 to 23. The low-pass filter 32 includes band A (HB) and band B (MB) as its passbands, but has an attenuation band on the higher frequency side than band A, so that the insertion loss in band B (MB) tends to be smaller than the insertion loss in band A (HB).

[0124] Furthermore, as shown in both Figures 9A and 9B, power amplifier 21 must have a wideband amplification characteristic, including band A and band B in its amplification band, and therefore the gain of power amplifier 21 is lower than the gains of power amplifiers 22 and 23, which have narrowband amplification characteristics.

[0125] In contrast, in the amplifier circuit 10D according to the fourth embodiment, when transmitting a band A (HB) signal, as shown in Fig. 8A, the power amplifier 21 is connected to the high-pass filter 31, and the power amplifier 22 is connected to the low-pass filter 32. When transmitting a band B (MB) signal, as shown in Fig. 8B, the power amplifier 21 is connected to the low-pass filter 32, and the power amplifier 23 is connected to the high-pass filter 31.

[0126] That is, when transmitting a band A (HB) signal, that is, when a band A (HB) high-frequency signal is input from input terminal 51a, the low gain of power amplifier 21 can be covered by high-pass filter 31 with small insertion loss for band A (HB). Also, when transmitting a band B (MB) signal, that is, when a band B (MB) high-frequency signal is input from input terminal 52a, the low gain of power amplifier 21 can be covered by low-pass filter 32 with small insertion loss for band B (MB). Therefore, it is possible to provide amplifier circuit 10D that can transmit band A signals and band B signals with low loss.

[0127] In the amplifier circuit 10D according to the fourth embodiment, a voltage-combining amplifier circuit according to a modified example of the fourth embodiment can be realized by changing the configuration of the combining circuit 30D. Specifically, the combining circuit 30D is replaced with a combining circuit having the following configuration. The combining circuit of the amplifier circuit according to the modified example of the fourth embodiment includes a transformer 60, a high-pass filter 31, and a low-pass filter 32. The transformer 60 has input and output coils that are magnetically coupled to each other. The low-pass filter 32 is connected between the input terminal 30a and one end 60a of the input coil. The high-pass filter 31 is connected between the input terminal 30b and the other end 60b of the input coil. One end 60c of the output coil is connected to the signal output terminal 130, and the other end of the output coil is connected to ground.

[0128] According to this, in the amplifier circuit according to the modification of the fourth embodiment, in the band A transmission mode, the phase difference between the first output signal at the output end of the power amplifier 21 and the second output signal at the output end of the power amplifier 22 is 90°, and the phase difference between the first input signal and the second input signal at the input coil of the transformer 60 is 180°. Also, in the band B transmission mode, the phase difference between the third output signal at the output end of the power amplifier 21 and the fourth output signal at the output end of the power amplifier 23 is 90°, and the phase difference between the first input signal and the second input signal at the input coil of the transformer 60 is 180°. Therefore, it is possible to operate as a voltage-combining balanced amplifier that is resistant to load fluctuations.

[0129] Furthermore, the power amplifier 21, high-pass filter 31, and low-pass filter 32 are shared between the band A transmission mode and the band B transmission mode. This makes it possible to provide a miniaturized multi-band compatible amplifier circuit compared to a conventional voltage-combining type balanced amplifier that has two power amplifiers, a high-pass filter, and a low-pass filter for the band A transmission mode, and two power amplifiers, a high-pass filter, and a low-pass filter for the band B transmission mode.

[0130] Furthermore, by providing the DP3T type switch 45, it becomes possible to selectively connect each of the power amplifiers 21 to 23 to either the low-pass filter 32 or the high-pass filter 31.

[0131] [5 Component Arrangement of the High-Frequency Circuit 1 According to the First Embodiment] Next, the component arrangement of the high-frequency circuit 1 according to the first embodiment will be described. FIG. 10 is a plan view of the high-frequency circuit 1 according to the first embodiment. FIG. 10(a) shows the arrangement of circuit components when the main surface 90a of the mounting board 90 is viewed from the positive side of the z-axis. FIG. 10(b) shows the arrangement of circuit components when the main surface 90b of the mounting board 90 is viewed from the positive side of the z-axis. Note that FIG. 10 omits the illustration of the mounting board 90 and the wiring connecting the circuit components. Also, FIG. 10 includes marks indicating the functions of the power amplifiers, switches, and filters to facilitate understanding of their relative positions, but these marks are not attached to the actual power amplifiers, switches, and filters.

[0132] The high-frequency circuit 1 shown in FIG. 10 further includes a mounting substrate 90 in addition to the components of the high-frequency circuit 1 shown in FIG.

[0133] The mounting substrate 90 has mutually opposing main surfaces 90a (first main surface) and 90b (second main surface), and is a substrate on which circuit components constituting the high-frequency circuit 1 are mounted. Examples of the mounting substrate 90 that can be used include a low-temperature co-fired ceramics (LTCC) substrate having a laminated structure of multiple dielectric layers, a high-temperature co-fired ceramics (HTCC) substrate, a component-embedded substrate, a substrate having a redistribution layer (RDL), a printed circuit board, and the like.

[0134] 10, power amplifiers 21 to 23, a high-pass filter 31, and a low-pass filter 32 are arranged on a main surface 90a of a mounting substrate 90. In addition, a semiconductor IC 70 is arranged on a main surface 90b of the mounting substrate 90.

[0135] The semiconductor IC 70 is an example of a first semiconductor IC and includes the switches 41 to 44. Note that the switches 43 and 44 do not necessarily have to be included in the semiconductor IC 70. The semiconductor IC 70 is configured using, for example, a complementary metal oxide semiconductor (CMOS), and specifically, may be manufactured using an SOI (silicon on insulator) process. The semiconductor IC 70 may also be configured of at least one of GaAs, SiGe, and GaN. Note that the semiconductor material of the semiconductor IC 70 is not limited to the above-mentioned materials.

[0136] Although not shown, the amplifiers 11 and 12 and the 90° hybrid circuits 51 and 52 that constitute the high-frequency circuit 1 may be disposed on the mounting substrate 90 .

[0137] A resin member may be disposed on the main surface 90a and / or the main surface 90b, and a shield electrode layer may be disposed to cover the surface and side surfaces of the resin member.

[0138] When the mounting substrate 90 is viewed from above, the semiconductor IC 70 at least partially overlaps the power amplifier 21 .

[0139] This allows the wiring connecting the power amplifier 21 and the switch 41 to be shorter, thereby reducing the transmission loss of the transmission signal passing through the relatively wideband, low-gain power amplifier 21, and reducing the transmission loss of the high-frequency circuit 1 and the amplifier circuit 10.

[0140] Furthermore, when the mounting substrate 90 is viewed from above, it is desirable that the common terminal 41 a of the switch 41 at least partially overlaps with the power amplifier 21 .

[0141] This allows the wiring connecting the power amplifier 21 and the switch 41 to be shorter, thereby further reducing the transmission loss of the high-frequency circuit 1 and the amplifier circuit 10.

[0142] Furthermore, when the mounting substrate 90 is viewed in a plan view, it is desirable that the common terminal 42a of the switch 42 at least partially overlaps with the low-pass filter 32, the selection terminal 42b at least partially overlaps with the power amplifier 22, and the selection terminal 42c at least partially overlaps with the power amplifier 23.

[0143] This allows the wiring connecting the power amplifiers 22 and 23 to the low-pass filter 32 to be shortened, thereby reducing the transmission loss of the high-frequency circuit 1 and the amplifier circuit 10 .

[0144] [6 Component Arrangement of High-Frequency Circuit 1B According to Example 2] Next, the component arrangement of the high-frequency circuit 1B according to Example 2 will be described. FIG. 11 is a plan view of the high-frequency circuit 1B according to Example 2. FIG. 11(a) shows the arrangement of circuit components when the main surface 90a of the mounting board 90 is viewed from the positive side of the z-axis. FIG. 11(b) shows the arrangement of circuit components when the main surface 90b of the mounting board 90 is viewed from the positive side of the z-axis. Note that FIG. 11 omits the illustration of the mounting board 90 and the wiring connecting the circuit components. Also, FIG. 11 includes marks indicating the functions of the power amplifiers, switches, and filters to facilitate understanding of their relative positions, but these marks are not attached to the actual power amplifiers, switches, and filters.

[0145] 11 includes an amplifier circuit 10B, filters 33 and 34, switches 43 and 44, an antenna connection terminal 100, and a mounting board 90. The filters 33 and 34, the switches 43 and 44, and the antenna connection terminal 100 have the same connection configurations as the filters 33 and 34, the switches 43 and 44, and the antenna connection terminal 100 of the high-frequency circuit 1 according to the embodiment. The component layout of the high-frequency circuit 1B according to Example 2 differs from the component layout of the high-frequency circuit 1 according to Example 1 in the layout of the power amplifiers 21 to 23, the high-pass filter 31 and the low-pass filter 32, and the semiconductor IC 70B. Therefore, in the following, a description of the component layout of the high-frequency circuit 1B according to this example that is the same as the component layout of the high-frequency circuit 1 according to Example 1 will be omitted, and the description will focus on the different configurations.

[0146] 11, power amplifiers 21 to 23, a high-pass filter 31, and a low-pass filter 32 are arranged on a main surface 90a of a mounting substrate 90. In addition, a semiconductor IC 70B is arranged on a main surface 90b of the mounting substrate 90.

[0147] The semiconductor IC 70B is an example of a first semiconductor IC and includes switches 41 to 44. Note that the switches 43 and 44 do not necessarily have to be included in the semiconductor IC 70B. The semiconductor IC 70B may be configured using, for example, a CMOS, and specifically may be manufactured using an SOI process. The semiconductor IC 70B may also be configured of at least one of GaAs, SiGe, and GaN. Note that the semiconductor material of the semiconductor IC 70B is not limited to the above-mentioned materials.

[0148] Although not shown, the amplifiers 11 and 12 and the 90° hybrid circuits 51 and 52 that constitute the high-frequency circuit 1B may be disposed on the mounting substrate 90.

[0149] When the mounting substrate 90 is viewed from above, the semiconductor IC 70B at least partially overlaps the power amplifier 21 .

[0150] This allows the wiring connecting the power amplifier 21 and the switch 41 to be shortened, thereby reducing the transmission loss of the transmission signal passing through the relatively wideband, low-gain power amplifier 21, and reducing the transmission loss of the high-frequency circuit 1B and the amplifier circuit 10B.

[0151] Furthermore, when the mounting substrate 90 is viewed from above, it is desirable that the common terminal 41 a of the switch 41 at least partially overlaps with the power amplifier 21 .

[0152] This allows the wiring connecting the power amplifier 21 and the switch 41 to be shorter, thereby further reducing the transmission loss of the high-frequency circuit 1B and the amplifier circuit 10B.

[0153] Furthermore, when the mounting substrate 90 is viewed in a plan view, it is desirable that the common terminal 42a of the switch 42 at least partially overlaps with the high-pass filter 31, the selection terminal 42b at least partially overlaps with the power amplifier 22, and the selection terminal 42c at least partially overlaps with the power amplifier 23.

[0154] This allows the wiring connecting the power amplifiers 22 and 23 to the high-pass filter 31 to be shortened, thereby reducing the transmission loss of the high-frequency circuit 1B and the amplifier circuit 10B.

[0155] [7 Component Arrangement of High-Frequency Circuit 1C According to Third Embodiment] Next, the component arrangement of the high-frequency circuit 1C according to the third embodiment will be described. FIG. 12 is a plan view of the high-frequency circuit 1C according to the third embodiment. FIG. 12(a) shows the arrangement of circuit components when the main surface 90a of the mounting board 90 is viewed from the positive side of the z-axis. FIG. 12(b) shows the arrangement of circuit components when the main surface 90b of the mounting board 90 is viewed from the positive side of the z-axis. Note that FIG. 12 omits the illustration of the mounting board 90 and the wiring connecting the circuit components. Also, FIG. 12 includes marks indicating the functions of the power amplifiers, switches, and filters to facilitate understanding of their relative positions, but these marks are not attached to the actual power amplifiers, switches, and filters.

[0156] 12 includes an amplifier circuit 10C, filters 33 and 34, switches 43 and 44, an antenna connection terminal 100, and a mounting board 90. The filters 33 and 34, the switches 43 and 44, and the antenna connection terminal 100 have the same connection configurations as the filters 33 and 34, the switches 43 and 44, and the antenna connection terminal 100 of the high-frequency circuit 1 according to the embodiment. The component layout of the high-frequency circuit 1C according to Example 3 differs from the component layout of the high-frequency circuit 1 according to Example 1 in the layout of the power amplifiers 21 to 23, the high-pass filter 31 and the low-pass filter 32, and the semiconductor IC 70C. Therefore, in the following, a description of the component layout of the high-frequency circuit 1C according to this example that is the same as the component layout of the high-frequency circuit 1 according to Example 1 will be omitted, and the description will focus on the different configurations.

[0157] 12, power amplifiers 21 to 23, a high-pass filter 31, and a low-pass filter 32 are arranged on a main surface 90a of the mounting substrate 90. In addition, a semiconductor IC 70C is arranged on a main surface 90b of the mounting substrate 90.

[0158] The semiconductor IC 70C is an example of a first semiconductor IC and includes switches 41, 43, 44, and 45. Note that the switches 43 and 44 do not necessarily have to be included in the semiconductor IC 70C. The semiconductor IC 70C may be configured using, for example, a CMOS, and specifically, may be manufactured using an SOI process. The semiconductor IC 70C may also be configured of at least one of GaAs, SiGe, and GaN. Note that the semiconductor material of the semiconductor IC 70C is not limited to the above-mentioned materials.

[0159] Although not shown, the amplifiers 11 and 12 and the 90° hybrid circuits 51 and 52 that constitute the high-frequency circuit 1C may be disposed on the mounting substrate 90.

[0160] When the mounting substrate 90 is viewed from above, the semiconductor IC 70C at least partially overlaps the power amplifier 21 .

[0161] This allows the wiring connecting the power amplifier 21 and the switch 41 to be shortened, thereby reducing the transmission loss of the transmission signal passing through the relatively wideband, low-gain power amplifier 21, and reducing the transmission loss of the high-frequency circuit 1C and the amplifier circuit 10C.

[0162] Furthermore, when the mounting board 90 is viewed from above, it is desirable that the common terminal 41 a of the switch 41 at least partially overlaps with the power amplifier 21 , and that the selection terminal 45 d of the switch 45 at least partially overlaps with the power amplifier 21 .

[0163] This allows the wiring connecting the power amplifier 21 and the switch 41 and the wiring connecting the power amplifier 21 and the switch 45 to be shorter, thereby further reducing the transmission loss of the high-frequency circuit 1C and the amplifier circuit 10C.

[0164] Furthermore, when mounting substrate 90 is viewed in a plan view, power amplifiers 21 to 23 are arranged in the negative y-axis direction (first direction) on main surface 90a in the order of power amplifier 22, power amplifier 21, and power amplifier 23, and selection terminals 45c, 45d, and 45e are arranged in the negative y-axis direction (first direction) on main surface 90b in the order of selection terminals 45c, 45d, and 45e.

[0165] This allows the total length of the wiring connecting the selection terminal 45d to which the power amplifier 21 is connected and the common terminal 45a and the wiring connecting the selection terminal 45d and the common terminal 45b to be shortened, thereby reducing the transmission loss of the transmission signal passing through the relatively wideband and low-gain power amplifier 21 and reducing the transmission loss of the high-frequency circuit 1C and the amplifier circuit 10C.

[0166] Furthermore, although not shown, when the mounting substrate 90 is viewed in a plan view, the common terminals 45a and 45b may be arranged in the order of the common terminals 45b and 45a in the negative y-axis direction (first direction) on the main surface 90b.

[0167] This allows the wiring connecting the common terminals 45a and 45b and the selection terminals 45c, 45d and 45e inside the switch 45 to be configured as shortest and without crossing, thereby reducing the transmission loss of the high-frequency circuit 1C and the amplifier circuit 10C and improving the isolation between the signal paths.

[0168] Furthermore, although not shown, the high-pass filter 31 and the low-pass filter 32 may be arranged in this order on the main surface 90a in the negative y-axis direction (first direction).

[0169] This allows the wiring not only inside switch 45 but also from selection terminals 45c, 45d, and 45e to low-pass filter 32 and high-pass filter 31 to be shortest and to be configured without crossing, thereby reducing transmission loss in high-frequency circuit 1C and amplifier circuit 10C and improving isolation between signal paths.

[0170] Furthermore, when the mounting substrate 90 is viewed from above, as shown in FIG. 12 , it is desirable that the common terminal 45 a of the switch 45 at least partially overlaps with the low-pass filter 32, the common terminal 45 b at least partially overlaps with the high-pass filter 31, and the selection terminal 45 d at least partially overlaps with the power amplifier 21.

[0171] This allows the wiring connecting the power amplifier 21 to the high-pass filter 31 and the low-pass filter 32 via the switch 45 to be shortened, thereby reducing transmission loss in the high-frequency circuit 1C and the amplifier circuit 10C.

[0172] [8 Component Arrangement of High-Frequency Circuit 1D According to Example 4] Next, the component arrangement of the high-frequency circuit 1D according to Example 4 will be described. FIG. 13 is a plan view of the high-frequency circuit 1D according to Example 4. FIG. 13(a) shows the arrangement of circuit components when the main surface 90a of the mounting board 90 is viewed from the positive side of the z-axis. FIG. 13(b) shows the arrangement of circuit components when the main surface 90b of the mounting board 90 is viewed from the positive side of the z-axis. Note that FIG. 13 omits the illustration of the mounting board 90 and the wiring connecting the circuit components. Also, FIG. 13 includes marks indicating the functions of the power amplifiers, switches, and filters to facilitate understanding of their relative positions, but these marks are not attached to the actual power amplifiers, switches, and filters.

[0173] 13 includes an amplifier circuit 10D, filters 33 and 34, switches 43 and 44, an antenna connection terminal 100, and a mounting board 90. The filters 33 and 34, the switches 43 and 44, and the antenna connection terminal 100 have the same connection configurations as the filters 33 and 34, the switches 43 and 44, and the antenna connection terminal 100 of the high-frequency circuit 1 according to the embodiment. The component layout of the high-frequency circuit 1D according to Example 4 differs from the component layout of the high-frequency circuit 1 according to Example 1 in the layout of the power amplifiers 21 to 23, the high-pass filter 31 and the low-pass filter 32, and the semiconductor IC 70D. Therefore, in the following, a description of the component layout of the high-frequency circuit 1D according to this example that is the same as the component layout of the high-frequency circuit 1 according to Example 1 will be omitted, and the description will focus on the different configurations.

[0174] 13, power amplifiers 21 to 23, a high-pass filter 31, and a low-pass filter 32 are arranged on a main surface 90a of the mounting substrate 90. In addition, a semiconductor IC 70D is arranged on a main surface 90b of the mounting substrate 90.

[0175] The semiconductor IC 70D is an example of a first semiconductor IC and includes switches 41, 43, 44, and 45. Note that the switches 43 and 44 do not necessarily have to be included in the semiconductor IC 70D. The semiconductor IC 70D may be configured using, for example, a CMOS, and specifically, may be manufactured using an SOI process. The semiconductor IC 70D may also be configured of at least one of GaAs, SiGe, and GaN. Note that the semiconductor material of the semiconductor IC 70D is not limited to the above-mentioned materials.

[0176] Although not shown, the amplifiers 11 and 12 and the 90° hybrid circuits 51 and 52 that constitute the high-frequency circuit 1D may be disposed on the mounting substrate 90.

[0177] When the mounting substrate 90 is viewed from above, the semiconductor IC 70D at least partially overlaps the power amplifier 21 .

[0178] This allows the wiring connecting the power amplifier 21 and the switch 41 to be shorter, thereby reducing the transmission loss of the transmission signal passing through the relatively wideband, low-gain power amplifier 21, and reducing the transmission loss of the high-frequency circuit 1D and the amplifier circuit 10D.

[0179] Furthermore, when the mounting board 90 is viewed from above, it is desirable that the common terminal 41 a of the switch 41 at least partially overlaps with the power amplifier 21 , and that the selection terminal 45 d of the switch 45 at least partially overlaps with the power amplifier 21 .

[0180] This allows the wiring connecting the power amplifier 21 and the switch 41 and the wiring connecting the power amplifier 21 and the switch 45 to be shorter, thereby further reducing the transmission loss of the high-frequency circuit 1D and the amplifier circuit 10D.

[0181] Furthermore, when mounting substrate 90 is viewed in a plan view, power amplifiers 21 to 23 are arranged in the negative y-axis direction (first direction) on main surface 90a in the order of power amplifier 22, power amplifier 21, and power amplifier 23, and selection terminals 45c, 45d, and 45e are arranged in the negative y-axis direction (first direction) on main surface 90b in the order of selection terminals 45c, 45d, and 45e.

[0182] This allows the total length of the wiring connecting the selection terminal 45d to which the power amplifier 21 is connected and the common terminal 45a and the wiring connecting the selection terminal 45d and the common terminal 45b to be shortened, thereby reducing the transmission loss of the transmission signal passing through the relatively wideband and low-gain power amplifier 21 and reducing the transmission loss of the high-frequency circuit 1D and the amplifier circuit 10D.

[0183] Furthermore, when the mounting substrate 90 is viewed from above, the common terminals 45a and 45b are arranged in this order on the main surface 90b in the negative y-axis direction (first direction).

[0184] This allows the wiring connecting the common terminals 45a and 45b and the selection terminals 45c, 45d, and 45e inside the switch 45 to be configured as shortest and without crossing, thereby reducing the transmission loss of the high-frequency circuit 1D and the amplifier circuit 10D and improving the isolation between the signal paths.

[0185] Furthermore, the high-pass filter 31 and the low-pass filter 32 may be arranged in this order on the main surface 90a in the negative y-axis direction (first direction).

[0186] This allows the wiring not only inside switch 45 but also from selection terminals 45c, 45d, and 45e to low-pass filter 32 and high-pass filter 31 to be shortest and to be configured without crossing, thereby reducing transmission loss in high-frequency circuit 1D and amplifier circuit 10D and improving isolation between signal paths.

[0187] Furthermore, when the mounting substrate 90 is viewed in a plan view, it is desirable that the common terminal 45a of the switch 45 at least partially overlaps with the high-pass filter 31, the common terminal 45b at least partially overlaps with the low-pass filter 32, and the selection terminal 45d at least partially overlaps with the power amplifier 21.

[0188] This allows the wiring connecting the power amplifier 21 to the high-pass filter 31 and the low-pass filter 32 via the switch 45 to be shortened, thereby reducing transmission loss in the high-frequency circuit 1D and the amplifier circuit 10D.

[0189] [9 Effects, etc.] As described above, the amplifier circuit 10 (10B) according to Example 1 (2) includes a 90° hybrid circuit 51 having an input terminal 51a and output terminals 51b and 51c, a 90° hybrid circuit 52 having an input terminal 52a and output terminals 52b and 52c, power amplifiers 21, 22, and 23, a switch 41 having a common terminal 41a and selection terminals 41b and 41c, a switch 42 having a common terminal 42a and selection terminals 42b and 42c, and a combiner circuit 30 (30B) having input terminals 30a, 30b and a signal output terminal 130. The output terminal 51b (51c) is connected to the selection terminal 41b, the output terminal 51c (51b) is connected to the input terminal of the power amplifier 22, the output terminal 52b (52c) is connected to the selection terminal 41c, the output terminal 52c (52b) is connected to the input terminal of the power amplifier 23, the common terminal 41a is connected to the input terminal of the power amplifier 21, the output terminal of the power amplifier 21 is connected to the input terminal 30a, the output terminal of the power amplifier 22 is connected to the selection terminal 42b, the output terminal of the power amplifier 23 is connected to the selection terminal 42c, and the common terminal 42a is connected to the input terminal 30b.

[0190] This allows the amplifier circuit 10 (10B) to transmit a band A signal using the power amplifiers 21 and 22 and transmit a band B signal using the power amplifiers 21 and 23 by switching the switches 41 and 42. When transmitting a band A signal, the phase difference between the band A signal at the output terminal of the power amplifier 21 and the band A signal at the output terminal of the power amplifier 22 is set to 90°, and the two signals can be combined by the combiner circuit. When transmitting a band B signal, the phase difference between the band B signal at the output terminal of the power amplifier 21 and the band B signal at the output terminal of the power amplifier 23 is set to 90°, and the two signals can be combined by the combiner circuit. This allows the amplifier circuit 10 (10B) to operate as a balanced amplifier that is resistant to load fluctuations. Furthermore, the power amplifier 21 and the combiner circuit are shared in both the band A transmission mode and the band B transmission mode. Therefore, it is possible to provide a miniaturized multi-band compatible amplifier circuit 10 (10B) compared to a conventional balanced amplifier that has two separate power amplifiers and combining circuits for Band A transmission mode and two separate power amplifiers and combining circuits for Band B transmission mode.

[0191] Furthermore, for example, in the amplifier circuit 10 (10B), the 90° hybrid circuit 51 is configured so that the phase difference between a first output signal output from the output terminal 51b (51c) and a second output signal output from the output terminal 51c (51b) is 90°, the 90° hybrid circuit 52 is configured so that the phase difference between a third output signal output from the output terminal 52b (52c) and a fourth output signal output from the output terminal 52c (52b) is 90°, the switch 41 is configured to switch between the connection between the common terminal 41a and the selection terminal 41b and the connection between the common terminal 41a and the selection terminal 41c, the switch 42 is configured to switch between the connection between the common terminal 42a and the selection terminal 42b and the connection between the common terminal 42a and the selection terminal 42c, and the combining circuit 30 is configured to output from the signal output terminal 130 a fifth output signal obtained by combining the first input signal input to the input terminal 30a and the second input signal input to the input terminal 30b.

[0192] This allows the amplifier circuit 10 (10B) to eliminate one power amplifier and one combiner circuit, while adding two switches to accommodate multiple bands, thereby making it possible to provide a compact, multi-band amplifier circuit 10 (10B).

[0193] For example, in the amplifier circuit 10 according to the first embodiment, the second output signal output from the output terminal 51c is 90° ahead in phase of the first output signal output from the output terminal 51b, the fourth output signal output from the output terminal 52c is 90° ahead in phase of the third output signal output from the output terminal 52b, and the synthesis circuit 30 includes a high-pass filter 31 connected between the input terminal 30a and the signal output terminal 130, and a low-pass filter 32 connected between the input terminal 30b and the signal output terminal 130.

[0194] According to this, in amplifier circuit 10, the phase difference between the first output signal at the output end of power amplifier 21 and the second output signal at the output end of power amplifier 22 can be set to 90°, and the phase difference between the first input signal and the second input signal at signal output terminal 130 can be set to 0°. Furthermore, the phase difference between the third output signal at the output end of power amplifier 21 and the fourth output signal at the output end of power amplifier 23 can be set to 90°, and the phase difference between the first input signal and the second input signal at signal output terminal 130 can be set to 0°. Therefore, it is possible to operate as a current-combining balanced amplifier that is resistant to load fluctuations.

[0195] Furthermore, for example, in an amplifier circuit 10A according to a modified example of Example 1, the second output signal output from output terminal 51c is 90° ahead in phase of the first output signal output from output terminal 51b, and the fourth output signal output from output terminal 52c is 90° ahead in phase of the third output signal output from output terminal 52b. The combining circuit 30A includes a transformer 60 having an input coil and an output coil, a low-pass filter 32 connected between the third input terminal and one end of the input coil, and a high-pass filter 31 connected between the fourth input terminal and the other end of the input coil, and one end of the output coil is connected to the signal output terminal 130 and the other end of the output coil is connected to ground.

[0196] According to this, in amplifier circuit 10A, the phase difference between the first output signal at the output end of power amplifier 21 and the second output signal at the output end of power amplifier 22 can be made 90°, and the phase difference between the first input signal and the second input signal at signal output terminal 130 can be made 180°. Furthermore, the phase difference between the third output signal at the output end of power amplifier 21 and the fourth output signal at the output end of power amplifier 23 can be made 90°, and the phase difference between the first input signal and the second input signal at signal output terminal 130 can be made 180°. Therefore, it is possible to operate as a voltage synthesis type balanced amplifier that is resistant to load fluctuations.

[0197] For example, in the amplifier circuit 10B according to the second embodiment, the second output signal output from the output terminal 51b is delayed in phase by 90° from the first output signal output from the output terminal 51c, the fourth output signal output from the output terminal 52b is delayed in phase by 90° from the third output signal output from the output terminal 52c, and the synthesis circuit 30B includes a low-pass filter 32 connected between the input terminal 30a and the signal output terminal 130, and a high-pass filter 31 connected between the input terminal 30b and the signal output terminal 130.

[0198] According to this, in amplifier circuit 10B, the phase difference between the first output signal at the output end of power amplifier 21 and the second output signal at the output end of power amplifier 22 can be set to 90°, and the phase difference between the first input signal and the second input signal at signal output terminal 130 can be set to 0°. Furthermore, the phase difference between the third output signal at the output end of power amplifier 21 and the fourth output signal at the output end of power amplifier 23 can be set to 90°, and the phase difference between the first input signal and the second input signal at signal output terminal 130 can be set to 0°. Therefore, it is possible to operate as a current-combining balanced amplifier that is resistant to load fluctuations.

[0199] Furthermore, for example, in an amplifier circuit according to a modified example of Example 2, the second output signal output from output terminal 51b is delayed in phase by 90° from the first output signal output from output terminal 51c, the fourth output signal output from output terminal 52b is delayed in phase by 90° from the third output signal output from output terminal 52c, and the composite circuit includes a transformer 60 having an input coil and an output coil, a high-pass filter 31 connected between input terminal 30a and one end of the input coil, and a low-pass filter 32 connected between input terminal 30b and the other end of the input coil, and one end of the output coil is connected to signal output terminal 130 and the other end of the output coil is connected to ground.

[0200] According to this, in the amplifier circuit according to the modification of the second embodiment, the phase difference between the first output signal at the output end of the power amplifier 21 and the second output signal at the output end of the power amplifier 22 can be set to 90°, and the phase difference between the first input signal and the second input signal at the signal output terminal 130 can be set to 180°. Furthermore, the phase difference between the third output signal at the output end of the power amplifier 21 and the fourth output signal at the output end of the power amplifier 23 can be set to 90°, and the phase difference between the first input signal and the second input signal at the signal output terminal 130 can be set to 180°. Therefore, it is possible to operate as a voltage synthesis type balanced amplifier that is resistant to load fluctuations.

[0201] Also, for example, in the amplifier circuit 10 (10A, 10B), the power amplifier 21 can amplify band A signals and band B signals, the power amplifier 22 can amplify band A signals, the power amplifier 23 can amplify band B signals, the power amplifier 23 does not perform amplification simultaneously with the power amplifier 22, when transmitting band A signals, the common terminal 41a and the selection terminal 41b are connected, and the common terminal 42a and the selection terminal 42b are connected, and when transmitting band B signals, the common terminal 41a and the selection terminal 41c are connected, and the common terminal 42a and the selection terminal 42c are connected.

[0202] This allows the band A transmission mode and the band B transmission mode to be supported by switching between the two switches 41 and 42, making it possible to provide a multi-band compatible amplifier circuit 10 (10A, 10B) with a simplified circuit configuration.

[0203] For example, the amplifier circuit 10 (10A, 10B) further includes a mounting substrate 90 having main surfaces 90a and 90b facing each other, the switches 41 and 42 are included in a semiconductor IC 70 (70B), the power amplifiers 21 to 23 are arranged on the main surface 90a, and the semiconductor IC 70 (70B) is arranged on the main surface 90b, and when the mounting substrate 90 is viewed in a plan view, the semiconductor IC 70 (70B) at least partially overlaps with the power amplifier 21.

[0204] This allows the wiring connecting the power amplifier 21 and the switch 41 to be shortened, thereby reducing the transmission loss of the transmission signal passing through the power amplifier 21, which has a wider bandwidth and lower gain than the power amplifiers 22 and 23, and reducing the transmission loss of the amplifier circuit 10 (10A, 10B).

[0205] Furthermore, for example, in the amplifier circuit 10 (10A, 10B), when the mounting substrate 90 is viewed from above, the common terminal 41a of the switch 41 at least partially overlaps with the power amplifier 21.

[0206] This allows the wiring connecting the power amplifier 21 and the switch 41 to be shorter, thereby further reducing the transmission loss of the amplifier circuit 10 (10A, 10B).

[0207] An amplifier circuit 10C (10D) according to Example 3 (4) includes a 90° hybrid circuit 51 having an input terminal 51a and output terminals 51b and 51c, a 90° hybrid circuit 52 having an input terminal 52a and output terminals 52b and 52c, power amplifiers 21, 22, and 23, a switch 41 having a common terminal 41a and selection terminals 41b and 41c, a switch 45 having common terminals 45a, 45b, and selection terminals 45c, 45d, and 45e, and a combining circuit 30C (30D) having input terminals 30a, 30b, and a signal output terminal 130. c (51b) is connected to the selection terminal 41b, the output terminal 51b (51c) is connected to the input terminal of the power amplifier 22, the output terminal 52b (52c) is connected to the selection terminal 41c, the output terminal 52c (52b) is connected to the input terminal of the power amplifier 23, the common terminal 41a is connected to the input terminal of the power amplifier 21, the output terminal of the power amplifier 21 is connected to the selection terminal 45d, the output terminal of the power amplifier 22 is connected to the selection terminal 45c, the output terminal of the power amplifier 23 is connected to the selection terminal 45e, the common terminal 45a is connected to the input terminal 30a, and the common terminal 45b is connected to the input terminal 30b.

[0208] This allows the amplifier circuit 10C (10D) to transmit a band A signal using the power amplifiers 21 and 22 and transmit a band B signal using the power amplifiers 21 and 23 by switching the switches 41 and 45. When transmitting a band A signal, the phase difference between the band A signal at the output terminal of the power amplifier 21 and the band A signal at the output terminal of the power amplifier 22 is set to 90°, and the two signals can be combined by the combiner circuit. When transmitting a band B signal, the phase difference between the band B signal at the output terminal of the power amplifier 21 and the band B signal at the output terminal of the power amplifier 23 is set to 90°, and the two signals can be combined by the combiner circuit. This allows the amplifier circuit 10C (10D) to operate as a balanced amplifier that is resistant to load fluctuations. Furthermore, the power amplifier 21 and the combiner circuit are shared in both the band A transmission mode and the band B transmission mode. Therefore, it is possible to provide a multi-band compatible amplifier circuit 10C (10D) that is smaller in size than a conventional balanced amplifier that has two power amplifiers and combining circuits for Band A transmission mode and two power amplifiers and combining circuits for Band B transmission mode. Furthermore, by providing a DP3T switch 45, it is possible to select either input terminal 30a or 30b as the connection destination for each of power amplifiers 21 to 23.

[0209] Also, for example, in the amplifier circuit 10C (10D), the 90° hybrid circuit 51 is configured so that the phase difference between the first output signal output from the output terminal 51c (51b) and the second output signal output from the output terminal 51b (51c) is 90°, the 90° hybrid circuit 52 is configured so that the phase difference between the third output signal output from the output terminal 52c (52b) and the fourth output signal output from the output terminal 52b (52c) is 90°, and the switch 41 is configured so that the common terminal 41a and the selection terminal 41b are connected and the common terminal 41a and the selection terminal 41b are connected and the common terminal 41b and the selection terminal 41c are connected and the selection terminal 41c ... The switch 45 is configured to switch the connection between the common terminal 45a and the selection terminal 45d and the connection between the common terminal 45b and the selection terminal 45c, and the connection between the common terminal 45a and the selection terminal 45e and the connection between the common terminal 45b and the selection terminal 45d, and the combination circuit 30C (30D) is configured to output from the signal output terminal 130 a fifth output signal that is a combination of the first input signal input to the input terminal 30a and the second input signal input to the input terminal 30b.

[0210] This allows the amplifier circuit 10C (10D) to eliminate one power amplifier and one combiner circuit, while adding two switches to accommodate multiple bands, thereby providing a compact multi-band amplifier circuit 10C (10D).

[0211] For example, in the amplifier circuit 10D according to the fourth embodiment, the second output signal output from the output terminal 51c is 90° ahead in phase with respect to the first output signal output from the output terminal 51b, and the fourth output signal output from the output terminal 52b is 90° behind in phase with respect to the third output signal output from the output terminal 52c. The synthesis circuit 30D includes a high-pass filter 31 connected between the input terminal 30a and the signal output terminal 130, and a low-pass filter 32 connected between the input terminal 30b and the signal output terminal 130.

[0212] According to this, in amplifier circuit 10D, the phase difference between the first output signal at the output end of power amplifier 21 and the second output signal at the output end of power amplifier 22 can be set to 90°, and the phase difference between the first input signal and the second input signal at signal output terminal 130 can be set to 0°. Furthermore, the phase difference between the third output signal at the output end of power amplifier 21 and the fourth output signal at the output end of power amplifier 23 can be set to 90°, and the phase difference between the first input signal and the second input signal at signal output terminal 130 can be set to 0°. Therefore, it is possible to operate as a current-combining balanced amplifier that is resistant to load fluctuations.

[0213] For example, in an amplifier circuit according to a modified example of Example 4, the second output signal output from output terminal 51c is 90° ahead in phase of the first output signal output from output terminal 51b, and the fourth output signal output from output terminal 52b is 90° behind in phase of the third output signal output from output terminal 52c. The composite circuit includes a transformer 60 having an input coil and an output coil, a low-pass filter 32 connected between input terminal 30a and one end of the input coil, and a high-pass filter 31 connected between input terminal 30b and the other end of the input coil, and one end of the output coil is connected to signal output terminal 130 and the other end of the output coil is connected to ground.

[0214] According to this, in the amplifier circuit according to the modification of the fourth embodiment, the phase difference between the first output signal at the output end of the power amplifier 21 and the second output signal at the output end of the power amplifier 22 can be set to 90°, and the phase difference between the first input signal and the second input signal at the signal output terminal 130 can be set to 180°. Furthermore, the phase difference between the third output signal at the output end of the power amplifier 21 and the fourth output signal at the output end of the power amplifier 23 can be set to 90°, and the phase difference between the first input signal and the second input signal at the signal output terminal 130 can be set to 180°. Therefore, it is possible to operate as a voltage synthesis type balanced amplifier that is resistant to load fluctuations.

[0215] Also, for example, in the amplifier circuit 10D, a high frequency signal of band A is input to the input terminal 51a, and a high frequency signal of band B, which is located on the lower frequency side than band A, is input to the input terminal 52a.

[0216] According to this, when transmitting a band A signal, that is, when a high-frequency signal of band A is input from input terminal 51a, the low gain of power amplifier 21 can be covered by high-pass filter 31 with small insertion loss for band A. Also, when transmitting a band B signal, that is, when a high-frequency signal of band B is input from input terminal 52a, the low gain of power amplifier 21 can be covered by low-pass filter 32 with small insertion loss for band B. Therefore, it is possible to provide amplifier circuit 10D that can transmit band A signals and band B signals with low loss.

[0217] For example, in the amplifier circuit 10C according to the third embodiment, the second output signal output from the output terminal 51b is delayed in phase by 90° from the first output signal output from the output terminal 51c, the fourth output signal output from the output terminal 52c is advanced in phase by 90° from the third output signal output from the output terminal 52b, and the synthesis circuit 30C includes a low-pass filter 32 connected between the input terminal 30a and the signal output terminal 130, and a high-pass filter 31 connected between the input terminal 30b and the signal output terminal 130.

[0218] According to this, in amplifier circuit 10C, the phase difference between the first output signal at the output end of power amplifier 21 and the second output signal at the output end of power amplifier 22 can be set to 90°, and the phase difference between the first input signal and the second input signal at signal output terminal 130 can be set to 0°. Furthermore, the phase difference between the third output signal at the output end of power amplifier 21 and the fourth output signal at the output end of power amplifier 23 can be set to 90°, and the phase difference between the first input signal and the second input signal at signal output terminal 130 can be set to 0°. Therefore, it is possible to operate as a current-combining balanced amplifier that is resistant to load fluctuations.

[0219] Also, for example, in amplifier circuit 10C (10D), power amplifier 21 can amplify signals of band A and band B, power amplifier 22 can amplify signals of band A, power amplifier 23 can amplify signals of band B, power amplifier 23 does not perform amplification simultaneously with power amplifier 22, when transmitting signals of band A, common terminal 41a and selection terminal 41b are connected, common terminal 45a and selection terminal 45d are connected, and common terminal 45b and selection terminal 45c are connected, and when transmitting signals of band B, common terminal 41a and selection terminal 41c are connected, common terminal 45a and selection terminal 45e are connected, and common terminal 45b and selection terminal 45d are connected.

[0220] This allows the band A transmission mode and the band B transmission mode to be supported by switching between the two switches 41 and 45, making it possible to provide a multi-band compatible amplifier circuit 10C (10D) with a simplified circuit configuration.

[0221] For example, the amplifier circuit 10C (10D) further includes a mounting substrate 90 having main surfaces 90a and 90b facing each other, the switches 41 and 45 are included in the semiconductor IC 70C (70D), the power amplifiers 21 to 23 are arranged on the main surface 90a, and the semiconductor IC 70C (70D) is arranged on the main surface 90b, and when the mounting substrate 90 is viewed in a plan view, the semiconductor IC 70C (70D) at least partially overlaps with the power amplifier 21.

[0222] This allows the wiring connecting the power amplifier 21 and the switch 41 to be shortened, thereby reducing the transmission loss of the transmission signal passing through the power amplifier 21, which has a wide bandwidth and low gain compared to the power amplifiers 22 and 23, and reducing the transmission loss of the amplifier circuit 10C (10D).

[0223] Furthermore, for example, in the amplifier circuit 10C (10D), when the mounting substrate 90 is viewed from above, the common terminal 41a at least partially overlaps with the power amplifier 21, and the selection terminal 45d at least partially overlaps with the power amplifier 21.

[0224] This allows the wiring connecting the power amplifier 21 and the switch 41 and the wiring connecting the power amplifier 21 and the switch 45 to be shorter, thereby further reducing the transmission loss of the high-frequency circuit 1C (1D) and the amplifier circuit 10C (10D).

[0225] Furthermore, for example, in amplifier circuit 10C (10D), when mounting substrate 90 is viewed in a plan view, power amplifiers 21 to 23 are arranged in the order of power amplifiers 22, 21, and 23 on main surface 90a in the negative direction of the y-axis (first direction), and selection terminals 45c, 45d, and 45e are arranged in the order of selection terminals 45c, 45d, and 45e on main surface 90b in the negative direction of the y-axis (first direction).

[0226] This allows the total length of the wiring connecting the selection terminal 45d to which the power amplifier 21 is connected and the common terminal 45a and the wiring connecting the selection terminal 45d and the common terminal 45b to be shortened, thereby reducing the transmission loss of the transmission signal passing through the relatively wideband and low-gain power amplifier 21 and reducing the transmission loss of the high-frequency circuit 1C (1D) and the amplifier circuit 10C (10D).

[0227] Further, for example, in the amplifier circuit 10C (10D), when the mounting substrate 90 is viewed in a plan view, the common terminals 45a and 45b are arranged in the order of the common terminals 45b and 45a on the main surface 90b in the negative y-axis direction (first direction).

[0228] This allows the wiring connecting the common terminals 45a and 45b and the selection terminals 45c, 45d, and 45e inside the switch 45 to be configured as shortest and without crossing, thereby reducing the transmission loss of the high-frequency circuit 1C (1D) and the amplifier circuit 10C (10D) and improving the isolation between the signal paths.

[0229] (Other Embodiments, etc.) While the amplifier circuits according to the embodiments of the present invention have been described above with reference to the embodiments, examples, and modifications, the amplifier circuits according to the present invention are not limited to the above-described embodiments, examples, and modifications. The present invention also includes other embodiments realized by combining any of the components in the above-described embodiments, examples, and modifications, modifications obtained by applying various modifications to the above-described embodiments, examples, and modifications that would occur to a person skilled in the art without departing from the spirit of the present invention, and various devices incorporating the above-described amplifier circuits.

[0230] For example, in the amplifier circuits according to the above-described embodiments, examples, and modifications, other circuit elements, wiring, etc. may be inserted between the paths connecting the circuit elements and signal paths disclosed in the drawings.

[0231] The features of the amplifier circuits described based on the above-described embodiments, examples, and modifications will be described below.

[0232] <1> A power amplifier comprising: a first 90° hybrid circuit having a first input terminal, a first output terminal, and a second output terminal; a second 90° hybrid circuit having a second input terminal, a third output terminal, and a fourth output terminal; a first power amplifier, a second power amplifier, and a third power amplifier; a first switch having a first common terminal, a first selection terminal, and a second selection terminal; a second switch having a second common terminal, a third selection terminal, and a fourth selection terminal; and a combiner circuit having a third input terminal, a fourth input terminal, and a fifth output terminal, wherein the first output terminal is connected to the first selection terminal, the second output terminal is connected to an input terminal of the second power amplifier, the third output terminal is connected to the second selection terminal, the fourth output terminal is connected to an input terminal of the third power amplifier, the first common terminal is connected to an input terminal of the first power amplifier, an output terminal of the first power amplifier is connected to the third input terminal, an output terminal of the second power amplifier is connected to the third selection terminal, and an output terminal of the third power amplifier is connected to the fourth selection terminal, The second common terminal is connected to the fourth input terminal.

[0233] <2> The amplifier circuit according to <1>, wherein the first 90° hybrid circuit is configured so that a phase difference between a first output signal output from the first output terminal and a second output signal output from the second output terminal is 90°; the second 90° hybrid circuit is configured so that a phase difference between a third output signal output from the third output terminal and a fourth output signal output from the fourth output terminal is 90°; the first switch is configured to switch a connection between the first common terminal and the first selection terminal and a connection between the first common terminal and the second selection terminal; the second switch is configured to switch a connection between the second common terminal and the third selection terminal and a connection between the second common terminal and the fourth selection terminal; and the combining circuit is configured to output from the fifth output terminal a fifth output signal obtained by combining the first input signal input to the third input terminal and the second input signal input to the fourth input terminal.

[0234] <3> The amplifier circuit according to <1> or <2>, wherein the second output signal output from the second output terminal is 90° ahead in phase of the first output signal output from the first output terminal, the fourth output signal output from the fourth output terminal is 90° ahead in phase of the third output signal output from the third output terminal, and the combining circuit includes: a high-pass filter connected between the third input terminal and the fifth output terminal; and a low-pass filter connected between the fourth input terminal and the fifth output terminal.

[0235] <4> The amplifier circuit according to <1> or <2>, wherein the second output signal output from the second output terminal is 90° ahead in phase of the first output signal output from the first output terminal, the fourth output signal output from the fourth output terminal is 90° ahead in phase of the third output signal output from the third output terminal, the combining circuit includes: a transformer having an input coil and an output coil; a low-pass filter connected between the third input terminal and one end of the input coil; and a high-pass filter connected between the fourth input terminal and the other end of the input coil, one end of the output coil is connected to the fifth output terminal, and the other end of the output coil is connected to ground.

[0236] <5> The amplifier circuit according to <1> or <2>, wherein the second output signal output from the second output terminal is delayed in phase by 90° from the first output signal output from the first output terminal, the fourth output signal output from the fourth output terminal is delayed in phase by 90° from the third output signal output from the third output terminal, and the combining circuit includes: a low-pass filter connected between the third input terminal and the fifth output terminal; and a high-pass filter connected between the fourth input terminal and the fifth output terminal.

[0237] <6> The amplifier circuit according to <1> or <2>, wherein the second output signal output from the second output terminal is delayed in phase by 90° from the first output signal output from the first output terminal, the fourth output signal output from the fourth output terminal is delayed in phase by 90° from the third output signal output from the third output terminal, the combining circuit includes: a transformer having an input coil and an output coil; a high-pass filter connected between the third input terminal and one end of the input coil; and a low-pass filter connected between the fourth input terminal and the other end of the input coil, one end of the output coil is connected to the fifth output terminal, and the other end of the output coil is connected to ground.

[0238] <7> The amplifier circuit according to any one of <1> to <6>, wherein the first power amplifier is capable of amplifying a first band signal and a second band signal, the second power amplifier is capable of amplifying the first band signal, the third power amplifier is capable of amplifying the second band signal and does not perform amplification simultaneously with the second power amplifier, when transmitting the first band signal, the first common terminal and the first selection terminal are connected, and the second common terminal and the third selection terminal are connected, and when transmitting the second band signal, the first common terminal and the second selection terminal are connected, and the second common terminal and the fourth selection terminal are connected.

[0239] <8> The amplifier circuit according to any one of <1> to <7>, further comprising a mounting substrate having a first main surface and a second main surface opposing each other, wherein the first switch and the second switch are included in a first semiconductor IC, the first power amplifier, the second power amplifier, and the third power amplifier are arranged on the first main surface, and the first semiconductor IC is arranged on the second main surface, and when the mounting substrate is viewed in a plane, at least a portion of the first semiconductor IC overlaps with the first power amplifier.

[0240] <9> The amplifier circuit according to <8>, wherein, in a plan view of the mounting substrate, the first common terminal at least partially overlaps with the first power amplifier.

[0241] <10> A power amplifier comprising: a first 90° hybrid circuit having a first input terminal, a first output terminal, and a second output terminal; a second 90° hybrid circuit having a second input terminal, a third output terminal, and a fourth output terminal; a first power amplifier, a second power amplifier, and a third power amplifier; a first switch having a first common terminal, a first selection terminal, and a second selection terminal; a second switch having a second common terminal, a third common terminal, a third selection terminal, a fourth selection terminal, and a fifth selection terminal; and a combiner circuit having a third input terminal, a fourth input terminal, and a fifth output terminal, wherein the first output terminal is connected to the first selection terminal, the second output terminal is connected to an input terminal of the second power amplifier, the third output terminal is connected to the second selection terminal, the fourth output terminal is connected to an input terminal of the third power amplifier, the first common terminal is connected to the input terminal of the first power amplifier, an output terminal of the first power amplifier is connected to the fourth selection terminal, and an output terminal of the second power amplifier is connected to the third selection terminal, an output terminal of the third power amplifier connected to the fifth select terminal; the second common terminal connected to the third input terminal; and the third common terminal connected to the fourth input terminal.

[0242] <11> The amplifier circuit according to <10>, wherein the first 90° hybrid circuit is configured so that a phase difference between a first output signal output from the first output terminal and a second output signal output from the second output terminal is 90°; the second 90° hybrid circuit is configured so that a phase difference between a third output signal output from the third output terminal and a fourth output signal output from the fourth output terminal is 90°; the first switch is configured to switch a connection between the first common terminal and the first selection terminal and a connection between the first common terminal and the second selection terminal; the second switch is configured to switch a connection between the second common terminal and the fourth selection terminal and a connection between the third common terminal and the third selection terminal, and a connection between the second common terminal and the fifth selection terminal and a connection between the third common terminal and the fourth selection terminal; and the combining circuit is configured to output from the fifth output terminal a fifth output signal obtained by combining the first input signal input to the third input terminal and the second input signal input to the fourth input terminal.

[0243] <12> The amplifier circuit according to <10> or <11>, wherein the second output signal output from the second output terminal is 90° ahead of the first output signal output from the first output terminal, the fourth output signal output from the fourth output terminal is 90° behind the third output signal output from the third output terminal, and the combining circuit includes: a high-pass filter connected between the third input terminal and the fifth output terminal; and a low-pass filter connected between the fourth input terminal and the fifth output terminal.

[0244] <13> The amplifier circuit according to <10> or <11>, wherein the second output signal output from the second output terminal is 90° ahead of the first output signal output from the first output terminal, the fourth output signal output from the fourth output terminal is 90° behind the third output signal output from the third output terminal, the combining circuit includes: a transformer having an input coil and an output coil; a low-pass filter connected between the third input terminal and one end of the input coil; and a high-pass filter connected between the fourth input terminal and the other end of the input coil, one end of the output coil is connected to the fifth output terminal, and the other end of the output coil is connected to ground.

[0245] <14> The amplifier circuit according to <13>, wherein a high-frequency signal of a first band is input from the first input terminal, and a high-frequency signal of a second band located on a lower frequency side than the first band is input from the second input terminal.

[0246] <15> The amplifier circuit according to <10> or <11>, wherein the second output signal output from the second output terminal is delayed in phase by 90° from the first output signal output from the first output terminal, the fourth output signal output from the fourth output terminal is advanced in phase by 90° from the third output signal output from the third output terminal, and the combining circuit includes: a low-pass filter connected between the third input terminal and the fifth output terminal; and a high-pass filter connected between the fourth input terminal and the fifth output terminal.

[0247] <16> The amplifier circuit according to any one of <10> to <15>, wherein the first power amplifier is capable of amplifying a first band signal and a second band signal, the second power amplifier is capable of amplifying the first band signal, the third power amplifier is capable of amplifying the second band signal and does not perform amplification simultaneously with the second power amplifier, when transmitting the first band signal, the first common terminal and the first selection terminal are connected, the second common terminal and the fourth selection terminal are connected, and the third common terminal and the third selection terminal are connected, and when transmitting the second band signal, the first common terminal and the second selection terminal are connected, the second common terminal and the fifth selection terminal are connected, and the third common terminal and the fourth selection terminal are connected.

[0248] <17> The amplifier circuit according to any one of <10> to <16>, further comprising a mounting substrate having a first main surface and a second main surface opposing each other, wherein the first switch and the second switch are included in a first semiconductor IC, the first power amplifier, the second power amplifier, and the third power amplifier are arranged on the first main surface, and the first semiconductor IC is arranged on the second main surface, and when the mounting substrate is viewed in a plane, at least a portion of the first semiconductor IC overlaps with the first power amplifier.

[0249] <18> The amplifier circuit according to <17>, wherein, in a plan view of the mounting substrate, the first common terminal at least partially overlaps with the first power amplifier, and the fourth selection terminal at least partially overlaps with the first power amplifier.

[0250] <19> The amplifier circuit according to <17> or <18>, wherein, in a plan view of the mounting board, the first power amplifier, the second power amplifier, and the third power amplifier are arranged in the order of the second power amplifier, the first power amplifier, and the third power amplifier in a first direction on the first main surface, and the third selection terminal, the fourth selection terminal, and the fifth selection terminal are arranged in the order of the third selection terminal, the fourth selection terminal, and the fifth selection terminal in the first direction on the second main surface.

[0251] <20> The amplifier circuit according to <19>, wherein, in a plan view of the mounting substrate, the second common terminal and the third common terminal are arranged in the first direction on the second main surface in the order of the third common terminal and the second common terminal.

[0252] The present invention can be widely used as an amplifier circuit disposed in a front end portion of communication devices such as mobile phones.

[0253] REFERENCE SIGNS LIST 1, 1B, 1C, 1D High frequency circuit 2 Antenna 3 RFIC 4 Communication device 10, 10A, 10B, 10C, 10D Amplification circuit 11, 12 Amplifier 21, 22, 23 Power amplifier 30, 30A, 30B, 30C, 30D Combiner circuit 30a, 30b, 51a, 52a Input terminal 31 High pass filter 32 Low pass filter 33, 34 Filter 41, 42, 43, 44, 45 Switch 41a, 42a, 43a, 45a, 45b Common terminal 41b, 41c, 42b, 42c, 43b, 43c, 45c, 45d, 45e Selection terminal 51, 52 90° hybrid circuit 51b, 51c, 52b, 52c Output terminal 60 Transformer 60a, 60c One end 60b Other end 70, 70B, 70C, 70D Semiconductor IC 90 Mounting substrate 90a, 90b Main surface 100 Antenna connection terminal 110, 120 Signal input terminal 130 Signal output terminal 311, 322 Capacitor 312, 321 Inductor

Claims

1. A power amplifier comprising: a first 90° hybrid circuit having a first input terminal, a first output terminal, and a second output terminal; a second 90° hybrid circuit having a second input terminal, a third output terminal, and a fourth output terminal; a first power amplifier, a second power amplifier, and a third power amplifier; a first switch having a first common terminal, a first selection terminal, and a second selection terminal; a second switch having a second common terminal, a third selection terminal, and a fourth selection terminal; and a combiner circuit having a third input terminal, a fourth input terminal, and a fifth output terminal, wherein the first output terminal is connected to the first selection terminal, the second output terminal is connected to the input terminal of the second power amplifier, the third output terminal is connected to the second selection terminal, the fourth output terminal is connected to the input terminal of the third power amplifier, the first common terminal is connected to the input terminal of the first power amplifier, the output terminal of the first power amplifier is connected to the third input terminal, the output terminal of the second power amplifier is connected to the third selection terminal, and the output terminal of the third power amplifier is connected to the fourth selection terminal. the second common terminal is connected to the fourth input terminal.

2. The amplifier circuit according to claim 1, wherein the first 90° hybrid circuit is configured so that a first output signal output from the first output terminal and a second output signal output from the second output terminal have a phase difference of 90°; the second 90° hybrid circuit is configured so that a third output signal output from the third output terminal and a fourth output signal output from the fourth output terminal have a phase difference of 90°; the first switch is configured to switch between a connection between the first common terminal and the first selection terminal and a connection between the first common terminal and the second selection terminal; the second switch is configured to switch between a connection between the second common terminal and the third selection terminal and a connection between the second common terminal and the fourth selection terminal; and the combining circuit is configured to output from the fifth output terminal a fifth output signal obtained by combining the first input signal input to the third input terminal and the second input signal input to the fourth input terminal.

3. The amplifier circuit according to claim 1 or 2, wherein the second output signal output from the second output terminal is 90° ahead in phase of the first output signal output from the first output terminal, the fourth output signal output from the fourth output terminal is 90° ahead in phase of the third output signal output from the third output terminal, and the combining circuit includes a high-pass filter connected between the third input terminal and the fifth output terminal, and a low-pass filter connected between the fourth input terminal and the fifth output terminal.

4. The amplifier circuit according to claim 1 or 2, wherein the second output signal output from the second output terminal is 90° ahead in phase of the first output signal output from the first output terminal, the fourth output signal output from the fourth output terminal is 90° ahead in phase of the third output signal output from the third output terminal, the combining circuit includes: a transformer having an input coil and an output coil; a low-pass filter connected between the third input terminal and one end of the input coil; and a high-pass filter connected between the fourth input terminal and the other end of the input coil, one end of the output coil is connected to the fifth output terminal, and the other end of the output coil is connected to ground.

5. The amplifier circuit according to claim 1 or 2, wherein the second output signal output from the second output terminal is delayed in phase by 90° from the first output signal output from the first output terminal, the fourth output signal output from the fourth output terminal is delayed in phase by 90° from the third output signal output from the third output terminal, and the combining circuit includes a low-pass filter connected between the third input terminal and the fifth output terminal, and a high-pass filter connected between the fourth input terminal and the fifth output terminal.

6. The amplifier circuit according to claim 1 or 2, wherein the second output signal output from the second output terminal is 90° behind in phase with the first output signal output from the first output terminal, the fourth output signal output from the fourth output terminal is 90° behind in phase with the third output signal output from the third output terminal, the combining circuit includes: a transformer having an input coil and an output coil; a high-pass filter connected between the third input terminal and one end of the input coil; and a low-pass filter connected between the fourth input terminal and the other end of the input coil, one end of the output coil is connected to the fifth output terminal, and the other end of the output coil is connected to ground.

7. The amplifier circuit according to any one of claims 1 to 6, wherein the first power amplifier is capable of amplifying first band signals and second band signals, the second power amplifier is capable of amplifying first band signals, the third power amplifier is capable of amplifying second band signals and does not perform amplification operations simultaneously with the second power amplifier, when transmitting first band signals, the first common terminal and the first selection terminal are connected, and the second common terminal and the third selection terminal are connected, and when transmitting second band signals, the first common terminal and the second selection terminal are connected, and the second common terminal and the fourth selection terminal are connected.

8. The amplifier circuit according to any one of claims 1 to 7, further comprising a mounting substrate having first and second main surfaces opposing each other, wherein the first switch and the second switch are included in a first semiconductor IC, the first power amplifier, the second power amplifier and the third power amplifier are arranged on the first main surface, the first semiconductor IC is arranged on the second main surface, and when the mounting substrate is viewed in a plane, at least a portion of the first semiconductor IC overlaps with the first power amplifier.

9. The amplifier circuit according to claim 8, wherein, when the mounting substrate is viewed from above, the first common terminal at least partially overlaps with the first power amplifier.

10. A power amplifier comprising: a first 90° hybrid circuit having a first input terminal, a first output terminal, and a second output terminal; a second 90° hybrid circuit having a second input terminal, a third output terminal, and a fourth output terminal; a first power amplifier, a second power amplifier, and a third power amplifier; a first switch having a first common terminal, a first selection terminal, and a second selection terminal; a second switch having a second common terminal, a third common terminal, a third selection terminal, a fourth selection terminal, and a fifth selection terminal; and a combiner circuit having a third input terminal, a fourth input terminal, and a fifth output terminal, wherein the first output terminal is connected to the first selection terminal, the second output terminal is connected to the input terminal of the second power amplifier, the third output terminal is connected to the second selection terminal, the fourth output terminal is connected to the input terminal of the third power amplifier, the first common terminal is connected to the input terminal of the first power amplifier, the output terminal of the first power amplifier is connected to the fourth selection terminal, and the output terminal of the second power amplifier is connected to the third selection terminal. an output terminal of the third power amplifier connected to the fifth select terminal; the second common terminal connected to the third input terminal; and the third common terminal connected to the fourth input terminal.

11. The amplifier circuit according to claim 10, wherein the first 90° hybrid circuit is configured so that a phase difference between a first output signal output from the first output terminal and a second output signal output from the second output terminal is 90°; the second 90° hybrid circuit is configured so that a phase difference between a third output signal output from the third output terminal and a fourth output signal output from the fourth output terminal is 90°; the first switch is configured to switch between a connection between the first common terminal and the first selection terminal and a connection between the first common terminal and the second selection terminal; the second switch is configured to switch between a connection between the second common terminal and the fourth selection terminal and a connection between the third common terminal and the third selection terminal, and a connection between the second common terminal and the fifth selection terminal and a connection between the third common terminal and the fourth selection terminal; and the combining circuit is configured to output from the fifth output terminal a fifth output signal obtained by combining the first input signal input to the third input terminal and the second input signal input to the fourth input terminal.

12. The amplifier circuit according to claim 10 or 11, wherein the second output signal output from the second output terminal is 90° ahead of the first output signal output from the first output terminal, the fourth output signal output from the fourth output terminal is 90° behind the third output signal output from the third output terminal, and the combining circuit includes a high-pass filter connected between the third input terminal and the fifth output terminal, and a low-pass filter connected between the fourth input terminal and the fifth output terminal.

13. The amplifier circuit according to claim 10 or 11, wherein the second output signal output from the second output terminal is 90° ahead of the first output signal output from the first output terminal, and the fourth output signal output from the fourth output terminal is 90° behind the third output signal output from the third output terminal, and the combining circuit includes: a transformer having an input coil and an output coil; a low-pass filter connected between the third input terminal and one end of the input coil; and a high-pass filter connected between the fourth input terminal and the other end of the input coil, and one end of the output coil is connected to the fifth output terminal, and the other end of the output coil is connected to ground.

14. The amplifier circuit according to claim 13, wherein a high frequency signal of a first band is input from the first input terminal, and a high frequency signal of a second band positioned lower in frequency than the first band is input from the second input terminal.

15. The amplifier circuit according to claim 10 or 11, wherein the second output signal output from the second output terminal lags in phase by 90° behind the first output signal output from the first output terminal, the fourth output signal output from the fourth output terminal leads in phase by 90° behind the third output signal output from the third output terminal, and the combining circuit includes a low-pass filter connected between the third input terminal and the fifth output terminal, and a high-pass filter connected between the fourth input terminal and the fifth output terminal.

16. The amplifier circuit according to any one of claims 10 to 15, wherein the first power amplifier is capable of amplifying first band signals and second band signals, the second power amplifier is capable of amplifying the first band signals, the third power amplifier is capable of amplifying the second band signals and does not perform amplification simultaneously with the second power amplifier, when transmitting the first band signals, the first common terminal and the first selection terminal are connected, the second common terminal and the fourth selection terminal are connected, and the third common terminal and the third selection terminal are connected, and when transmitting the second band signals, the first common terminal and the second selection terminal are connected, the second common terminal and the fifth selection terminal are connected, and the third common terminal and the fourth selection terminal are connected.

17. The amplifier circuit according to any one of claims 10 to 16, further comprising a mounting substrate having first and second main surfaces opposing each other, wherein the first switch and the second switch are included in a first semiconductor IC, the first power amplifier, the second power amplifier, and the third power amplifier are arranged on the first main surface, and the first semiconductor IC is arranged on the second main surface, and when the mounting substrate is viewed in a plane, at least a portion of the first semiconductor IC overlaps with the first power amplifier.

18. The amplifier circuit according to claim 17, wherein, when the mounting substrate is viewed in a plan view, the first common terminal at least partially overlaps with the first power amplifier, and the fourth selection terminal at least partially overlaps with the first power amplifier.

19. The amplifier circuit according to claim 17 or 18, wherein, when the mounting board is viewed in a plan view, the first power amplifier, the second power amplifier, and the third power amplifier are arranged in a first direction on the first main surface in the order of the second power amplifier, the first power amplifier, and the third power amplifier, and the third selection terminal, the fourth selection terminal, and the fifth selection terminal are arranged in the first direction on the second main surface in the order of the third selection terminal, the fourth selection terminal, and the fifth selection terminal.

20. The amplifier circuit according to claim 19, wherein, when the mounting substrate is viewed in a plane, the second common terminal and the third common terminal are arranged in the first direction on the second main surface in the order of the third common terminal and the second common terminal.

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