High-frequency module

Abstract

The present invention provides a high-frequency module that enables miniaturization and improved isolation between components. [Solution] The high-frequency module 1 includes an elastic wave filter 41, which includes a first elastic wave filter 411 connected to the output terminal of a power amplifier 11 and a second elastic wave filter 412 connected to the input terminal of a low-noise amplifier 21; elastic wave filters 42 and 43; a transformer 31 including primary and secondary coils formed by wiring on multiple layers of a module substrate 90; and inductors 61 to 63 connected between the second elastic wave filter and the low-noise amplifier. Metal shields S1 and S2 are formed on at least a portion of at least one side of the elastic wave filter, and the metal shields are positioned between the transformer and the inductors in a plan view of the module substrate.

Description

Technical Field

[0001] The present invention relates to a high-frequency module.

Background Art

[0002] In mobile communication devices such as mobile phones, particularly with the progress of multi-band development, the number of components constituting a high-frequency front-end circuit has been increasing. Accordingly, Patent Document 1 discloses a technique for achieving miniaturization of a module while ensuring isolation between components by arranging an elastic wave filter having a shield electrode formed on a side surface between an antenna switch and a power amplifier, and between a band select switch and a power amplifier controller.

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] However, in the above conventional technique, isolation between components may not be sufficient in some cases.

[0005] Accordingly, the present invention provides a high-frequency module that can achieve miniaturization and improve isolation between components.

Means for Solving the Problem

[0006] A high-frequency module according to one aspect of the present invention comprises a module substrate, two power amplifiers disposed on the module substrate, a first elastic wave filter disposed on the module substrate and connected to the output terminals of the two power amplifiers, a low-noise amplifier disposed on the module substrate, a second elastic wave filter disposed on the module substrate and connected to the input terminal of the low-noise amplifier, a transformer including a primary coil and a secondary coil formed by wiring on multiple layers of the module substrate, and an inductor disposed on the module substrate and connected between the second elastic wave filter and the low-noise amplifier, wherein both ends of the primary coil are connected to the output terminals of the two power amplifiers, and one end of the secondary coil is connected to the first elastic wave filter, and the inductor is located between the second elastic wave filter and the low-noise amplifier, wherein a first metal shield is formed on at least a portion of at least one side of the first elastic wave filter and the second elastic wave filter, and in a plan view of the module substrate, the first metal shield is disposed between the transformer and the inductor. [Effects of the Invention]

[0007] According to the present invention, it is possible to miniaturize high-frequency modules and improve isolation between components. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a circuit diagram of a communication device according to an embodiment. [Figure 2] Figure 2 is a plan view of a high-frequency module according to an embodiment. [Figure 3] Figure 3 is a plan view of a high-frequency module according to an embodiment. [Figure 4] Figure 4 is a cross-sectional view of a high-frequency module according to an embodiment. [Figure 5] Figure 5 is a cross-sectional view of a high-frequency module according to an embodiment. [Figure 6] Figure 6 is a cross-sectional view of a high-frequency module according to an embodiment. [Figure 7A]Figure 7A is a plan view of the transformer in the first layer of the module substrate according to the embodiment. [Figure 7B] Figure 7B is a plan view of the transformer in the second layer of the module substrate according to the embodiment. [Figure 7C] Figure 7C is a plan view of the transformer in the third layer of the module substrate according to the embodiment. [Figure 8] Figure 8 is a plan view of the transformers in the second and third layers of the module substrate according to the embodiment. [Figure 9] Figure 9 is a partial cross-sectional view of a high-frequency module according to a modified example of the embodiment. [Modes for carrying out the invention]

[0009] The embodiments of the present invention will be described in detail below with reference to the drawings. Note that the embodiments described below are all general or specific examples. The numerical values, shapes, materials, components, arrangement of components, and connection configurations shown in the following embodiments are examples only and are not intended to limit the present invention.

[0010] The figures are schematic diagrams that have been appropriately emphasized, omitted, or had their proportions adjusted to illustrate the present invention, and are not necessarily strictly accurate representations. Actual shapes, positional relationships, and proportions may differ. In each figure, substantially identical components are denoted by the same reference numerals, and redundant explanations may be omitted or simplified.

[0011] In the following figures, the x and y axes are mutually orthogonal axes on a plane parallel to the main surface of the module substrate. The z axis is perpendicular to the main surface of the module substrate, with its positive direction indicating upwards and its negative direction indicating downwards.

[0012] In the following description, the term "connected" includes not only cases of direct connection via connection terminals and / or wiring conductors, but also cases of electrical connection via other circuit elements. The phrase "A is switchably connected to B" means that connection and disconnection between A and B can be switched, and means that A is connected to B via a switch. Note that "A is connected to B" includes "A is switchably connected to B".

[0013] The phrase "C is connected between A and B" means that one end of C is connected to A and the other end of C is connected to B, which means that C is connected in series on the path connecting A and B. The phrase "C is connected between the path connecting A and B and ground" means that one end of C is connected to the path connecting A and B and the other end of C is connected to ground, which means that C is connected in shunt to the path connecting A and B. The "path connecting A and B" means a path formed of a conductor that electrically connects A to B.

[0014] The "passband of a filter" refers to the portion of the frequency spectrum transmitted by the filter, and is defined as the frequency band between two frequencies that is 3 dB higher than the minimum power insertion loss of the filter.

[0015] The "transmission band" means a frequency band used for transmission in a communication device, and the "reception band" means a frequency band used for reception in a communication device. For example, in an FDD (Frequency Division Duplex) band, different frequency bands (uplink band and downlink band) are used as the transmission band and the reception band. Also for example, in a TDD (Time Division Duplex) band, the same frequency band is used for the transmission band and the reception band.

[0016] The term "harmonic band of a predetermined band" means a band from n times the lower frequency end of the predetermined band to n times the upper frequency end of the predetermined band. Here, n is a natural number of 2 or greater. For example, the second harmonic band of the predetermined band is the band from twice the lower frequency end of the predetermined band to twice the upper frequency end of the predetermined band, and the third harmonic band of the predetermined band is the band from three times the lower frequency end of the predetermined band to three times the upper frequency end of the predetermined band. When no order is added, the term "harmonic band" means harmonic bands of all orders.

[0017] The term "simultaneously communicable band combination" means a combination of a plurality of frequency bands that can simultaneously transmit, simultaneously receive, or simultaneously transmit and receive, and is predefined by standardization organizations and the like (e.g., 3GPP (registered trademark) (3rd Generation Partnership Project), IEEE (Institute of Electrical and Electronics Engineers), etc.). Examples of "simultaneous communication" include CA (Carrier Aggregation), EN-DC (E-UTRAN New Radio - Dual Connectivity), NR-DC (New Radio - Dual Connectivity), and NE-DC (New Radio E-UTRAN - Dual Connectivity).

[0018] The term "terminal" means a point where a conductor in a circuit element terminates. When the impedance of a conductor between circuit elements is sufficiently low, the terminal is interpreted not only as a single point but also as any point on the conductor between circuit elements or the entire conductor. The term "node" means a point between circuit elements. When the impedance of a conductor between circuit elements is sufficiently low, the node is interpreted not only as a single point but also as any point on the conductor between circuit elements or the entire conductor.

[0019] "A component is placed on a substrate" includes the component being placed on the main surface of the substrate, and the component being placed within the substrate. "A component is placed on the main surface of the substrate" includes the component being placed in contact with the main surface of the substrate, as well as the component being placed above the main surface without contact with it (for example, the component being stacked on top of other components placed in contact with the main surface). Furthermore, "a component is placed on the main surface of the substrate" may also include the component being placed in a recess formed in the main surface. "A component is placed within the substrate" includes the component being encapsulated within the substrate, as well as the entire component being placed between the two main surfaces of the substrate but part of the component not being covered by the substrate, and only part of the component being placed within the substrate.

[0020] "Plane view of the substrate" means viewing an object by orthogonally projecting it onto the xy-plane in the negative z-axis direction. "In a plan view of the substrate, A overlaps with B" means that the region of A projected onto the xy-plane overlaps with the region of B projected onto the xy-plane.

[0021] "A is located between B and C" means that at least one of the line segments connecting any point in B and any point in C passes through A. "A is located further from C than B" means that the distance between A and C is greater than the distance between B and C. Here, "the distance between A(B) and C" means the length of the shortest line segment (i.e., the shortest distance) among the line segments connecting any point on the surface of A(B) and any point on the surface of C.

[0022] Terms indicating the relationship between elements, such as "parallel" and "perpendicular," terms indicating the shape of elements, such as "C-shape" and "straight line," and numerical ranges do not represent only strict meanings, but also include substantially equivalent ranges, such as errors of a few percent.

[0023] (Embodiment) Embodiments are described below.

[0024] [1.1. Configuration of the communication device] First, the configuration of the communication device 5 according to this embodiment will be described with reference to Figure 1. Figure 1 is a circuit diagram of the communication device 5 according to this embodiment.

[0025] Figure 1 shows an exemplary configuration, and the communication device 5 can be implemented using a wide variety of circuit implementations and circuit technologies. Therefore, the description of the communication device 5 provided below should not be interpreted restrictively.

[0026] The communication device 5 can be used to provide wireless connectivity. For example, the communication device 5 can be implemented in a UE (Unmanned Environment) on a cellular network (also called a mobile network) such as a mobile phone, smartphone, tablet computer, or wearable device. In another example, by implementing the communication device 5, wireless connectivity can be provided to IoT (Internet of Things) sensor devices, medical / healthcare devices, cars, unmanned aerial vehicles (UAVs) (so-called drones), and automated guided vehicles (AGVs). In yet another example, by implementing the communication device 5, wireless connectivity can also be provided in a wireless access point or wireless hotspot.

[0027] The communication device 5 comprises a high-frequency module 1, antennas 2a and 2b, an RFIC (Radio Frequency Integrated Circuit) 3, and a BBIC (Baseband Integrated Circuit) 4.

[0028] The high-frequency module 1 can transmit high-frequency signals between antennas 2a and 2b and RFIC 3. The circuit configuration of the high-frequency module 1 will be described later with reference to Figure 2.

[0029] Antennas 2a and 2b are connected to the high-frequency module 1. Antennas 2a and 2b can receive high-frequency signals from the high-frequency module 1 and transmit them to the outside of the communication device 5. Furthermore, antennas 2a and 2b can receive high-frequency signals from outside the communication device 5 and supply them to the high-frequency module 1. Note that some or all of antennas 2a and 2b do not need to be included in the communication device 5. In addition, the communication device 5 may have one or more antennas in addition to antennas 2a and 2b.

[0030] RFIC3 is an example of a signal processing circuit that processes high-frequency signals. Specifically, RFIC3 processes the transmission signal input from BBIC4 by upconversion, etc., and outputs the high-frequency transmission signal generated by this signal processing to high-frequency module 1. Furthermore, RFIC3 can also process the high-frequency reception signal input via high-frequency module 1 by downconversion, etc., and output the reception signal generated by this signal processing to BBIC4. RFIC3 may also have a control unit that controls switches and amplifiers, etc., of high-frequency module 1. Note that some or all of the control unit functions of RFIC3 may be included outside of RFIC3, for example, in BBIC4 and / or high-frequency module 1.

[0031] BBIC4 is a baseband signal processing circuit that processes signals using a frequency band lower than the high-frequency signal transmitted by the high-frequency module 1. Examples of signals processed by BBIC4 include image signals for image display and / or voice signals for communication via a speaker. Note that BBIC4 does not necessarily have to be included in the communication device 5.

[0032] [1.2. Circuit configuration of high-frequency module 1] Next, the circuit configuration of the high-frequency module 1 according to this embodiment will be described with reference to Figure 1. Note that Figure 1 shows an exemplary circuit configuration, and the high-frequency module 1 can be implemented using a wide variety of circuit implementations and circuit technologies. Therefore, the description of the high-frequency module 1 provided below should not be interpreted as restrictive.

[0033] The high-frequency module 1 includes a power amplification circuit 11, low-noise amplifiers 21, 22 and 23, a duplexer 41, elastic wave filters 42 and 43, a switch circuit 51, inductors 61, 62 and 63, antenna connection terminals 101 and 102, a high-frequency input terminal 103, and high-frequency output terminals 104, 105 and 106.

[0034] Antenna connection terminals 101 and 102 are external connection terminals of the high-frequency module 1. Antenna connection terminals 101 and 102 are terminals for supplying high-frequency signals to antennas 2a and 2b, and terminals for receiving high-frequency signals from antennas 2a and 2b. Antenna connection terminals 101 and 102 are connected to antennas 2a and 2b, respectively, outside the high-frequency module 1, and are connected to the switch circuit 51 inside the high-frequency module 1.

[0035] The high-frequency input terminal 103 is an external connection terminal of the high-frequency module 1 and is a terminal for receiving high-frequency signals from the RFIC 3. The high-frequency input terminal 103 is connected to the RFIC 3 outside the high-frequency module 1 and to the power amplification circuit 11 inside the high-frequency module 1.

[0036] The high-frequency output terminals 104-106 are external connection terminals of the high-frequency module 1 and are used to supply high-frequency signals to the RFIC 3. The high-frequency output terminals 104-106 are connected to the RFIC 3 externally and to the low-noise amplifiers 21-23 internally within the high-frequency module 1, respectively.

[0037] The power amplifier circuit 11 is a differential amplifier type multi-stage amplifier circuit and is connected between the high-frequency input terminal 103 and the transformer 31. The power amplifier circuit 11 can amplify the band A transmission signal supplied from the RFIC 3 via the high-frequency input terminal 103. The power amplifier circuit 11 comprises power amplifiers 111, 112 and 113 and a transformer 114.

[0038] Power amplifiers 111 and 112 correspond to the output stages (also called power stages) of a multi-stage amplification circuit. The input terminals of power amplifiers 111 and 112 are connected to both ends of the secondary coil 1142 of transformer 114, respectively, and the output terminals of power amplifiers 111 and 112 are connected to both ends of the primary coil 311 of transformer 31, respectively. Power amplifiers 111 and 112 can amplify the band A transmission signal amplified by power amplifier 113 using the power supply voltage supplied from a power supply (not shown).

[0039] The power amplifier 113 corresponds to the input stage (also called the drive stage) of a multi-stage amplification circuit. The input terminal of the power amplifier 113 is connected to the high-frequency input terminal 103, and the output terminal of the power amplifier 113 is connected to one end of the primary coil 1141 of the transformer 114. The power amplifier 113 can amplify the band A transmission signal supplied from the RFIC 3 via the high-frequency input terminal 103 using the power supply voltage supplied from a power supply (not shown).

[0040] The transformer 114 is a so-called balun and includes a primary coil 1141 and a secondary coil 1142 that can be coupled to the primary coil 1141. One end of the primary coil 1141 is connected to the output terminal of the power amplifier 113, and the other end of the primary coil 1141 is connected to ground. One end of the secondary coil 1142 is connected to the input terminal of the power amplifier 111, and the other end of the secondary coil 1142 is connected to the input terminal of the power amplifier 112. The transformer 114 can convert the unbalanced signal amplified by the power amplifier 113 into a balanced signal and supply the balanced signal to the power amplifiers 111 and 112.

[0041] Note that the power amplifier circuit 11 does not have to be a multi-stage amplifier circuit. In this case, the power amplifier 113 and / or transformer 114 do not have to be included in the power amplifier circuit 11. Also, the power amplifier circuit 11 does not have to be a differential amplifier type power amplifier circuit. For example, the power amplifier circuit 11 may be a balanced power amplifier circuit or a Doherty amplifier circuit.

[0042] The low-noise amplifier 21 is connected between the elastic wave filter 412 and the high-frequency output terminal 104. Specifically, the input terminal of the low-noise amplifier 21 is connected to the elastic wave filter 412 via an inductor 61, and the output terminal of the low-noise amplifier 21 is connected to the high-frequency output terminal 104. The low-noise amplifier 21 can amplify the received signal in band A using power supplied from a power supply (not shown).

[0043] The low-noise amplifier 22 is connected between the elastic wave filter 42 and the high-frequency output terminal 105. Specifically, the input terminal of the low-noise amplifier 22 is connected to the elastic wave filter 42 via an inductor 62, and the output terminal of the low-noise amplifier 22 is connected to the high-frequency output terminal 105. The low-noise amplifier 22 can amplify the received signal in band B using power supplied from a power supply (not shown).

[0044] The low-noise amplifier 23 is connected between the elastic wave filter 43 and the high-frequency output terminal 106. Specifically, the input terminal of the low-noise amplifier 23 is connected to the elastic wave filter 43 via an inductor 63, and the output terminal of the low-noise amplifier 23 is connected to the high-frequency output terminal 106. The low-noise amplifier 23 can amplify the received signal in band C using power supplied from a power supply (not shown).

[0045] The transformer 31 is a so-called balun and is connected between the power amplifiers 111 and 112 and the elastic wave filter 411. The transformer 31 includes a primary coil 311 and a secondary coil 312 that can be coupled to the primary coil 311. One end of the primary coil 311 is connected to the output terminal of the power amplifier 111, and the other end of the primary coil 311 is connected to the output terminal of the power amplifier 112. One end of the secondary coil 312 is connected to the elastic wave filter 411, and the other end of the secondary coil 312 is connected to ground. The transformer 31 can convert the balanced signals amplified by the power amplifiers 111 and 112 into unbalanced signals and supply these unbalanced signals to antennas 2a or 2b via the elastic wave filter 411.

[0046] The duplexer 41 is connected between the antenna connection terminals 101 and 102 and the power amplification circuit 11 and the low-noise amplifier 21. The duplexer 41 includes elastic wave filters 411 and 412 and can separate the transmitted and received signals of band A.

[0047] The elastic wave filter 411 (A-Tx) is an example of a first elastic wave filter and is connected between the antenna connection terminals 101 and 102 and the power amplifier circuit 11. Specifically, one end of the elastic wave filter 411 is connected to the selection terminal 513 of the switch circuit 51, and the other end of the elastic wave filter 411 is connected to one end of the secondary coil 312 of the transformer 31. The elastic wave filter 411 is a bandpass filter having a passband that includes the transmission band of band A, and can pass signals within the transmission band of band A and attenuate signals outside the transmission band of band A. Note that the elastic wave filter 411 is not limited to a bandpass filter. For example, the elastic wave filter 411 may be a band elimination filter, a high-pass filter, a low-pass filter, or any combination thereof.

[0048] The elastic wave filter 412 (A-Rx) is an example of a second elastic wave filter and is connected between the antenna connection terminals 101 and 102 and the low-noise amplifier 21. Specifically, one end of the elastic wave filter 412 is connected to the selection terminal 513 of the switch circuit 51, and the other end of the elastic wave filter 412 is connected to the input terminal of the low-noise amplifier 21 via the inductor 61. The elastic wave filter 412 is a bandpass filter having a passband that includes the receiving band of band A, and can pass signals within the receiving band of band A and attenuate signals outside the receiving band of band A. Note that the elastic wave filter 412 is not limited to a bandpass filter. For example, the elastic wave filter 412 may be a band-elimination filter, a high-pass filter, a low-pass filter, or any combination thereof.

[0049] The elastic wave filter 42 (B-Rx) is an example of a second elastic wave filter and is connected between the antenna connection terminals 101 and 102 and the low-noise amplifier 22. Specifically, one end of the elastic wave filter 42 is connected to the selection terminal 513 of the switch circuit 51, and the other end of the elastic wave filter 42 is connected to the input terminal of the low-noise amplifier 22 via the inductor 62. The elastic wave filter 42 is a bandpass filter having a passband that includes the receiving band of band B, and can pass signals within the receiving band of band B and attenuate signals outside the receiving band of band B. Note that the elastic wave filter 42 is not limited to a bandpass filter. For example, the elastic wave filter 42 may be a band elimination filter, a high-pass filter, a low-pass filter, or any combination thereof.

[0050] The elastic wave filter 43 (C-Rx) is an example of a second elastic wave filter and is connected between the antenna connection terminals 101 and 102 and the low-noise amplifier 23. Specifically, one end of the elastic wave filter 43 is connected to the selection terminal 514 of the switch circuit 51, and the other end of the elastic wave filter 43 is connected to the input terminal of the low-noise amplifier 23 via the inductor 63. The elastic wave filter 43 is a bandpass filter having a passband that includes the receiving band of band C, and can pass signals within the receiving band of band C and attenuate signals outside the receiving band of band C. Note that the elastic wave filter 43 is not limited to a bandpass filter. For example, the elastic wave filter 43 may be a band-elimination filter, a high-pass filter, a low-pass filter, or any combination thereof. Also, the elastic wave filter 43 does not have to be included in the high-frequency module 1.

[0051] Note that some parts of the elastic wave filters 412, 42, and 43 do not need to be included in the high-frequency module 1. In other words, the high-frequency module 1 may include only one of the elastic wave filters 412, 42, and 43, or any two of the elastic wave filters 412, 42, and 43. If the elastic wave filter 412 is not included in the high-frequency module 1, the low-noise amplifier 21 and inductor 61 also do not need to be included in the high-frequency module 1. Similarly, if the elastic wave filter 42 is not included in the high-frequency module 1, the low-noise amplifier 22 and inductor 62 also do not need to be included in the high-frequency module 1. Furthermore, if the elastic wave filter 43 is not included in the high-frequency module 1, the low-noise amplifier 23 and inductor 63 also do not need to be included in the high-frequency module 1.

[0052] The switch circuit 51 is connected between the antenna connection terminals 101 and 102 and the elastic wave filters 411, 412, 42, and 43. The switch circuit 51 includes common terminals 511 and 512 and select terminals 513 and 514. The common terminals 511 and 512 are connected to the antenna connection terminals 101 and 102, respectively. The select terminal 513 is connected to the elastic wave filters 411, 412, and 42. The select terminal 514 is connected to the elastic wave filter 43. In this connection configuration, the switch circuit 51 can exclusively connect the common terminals 511 and 512 to the select terminals 513 and 514 based, for example, on a digital control signal from the RFIC 3. The switch circuit 51 is composed of, for example, a DPDT (Double-Pole Double-Throw) type switch circuit. Note that the switch circuit 51 does not necessarily have to be included in the high-frequency module 1.

[0053] The inductor 61 is connected between the elastic wave filter 412 and the low-noise amplifier 21. Specifically, one end of the inductor 61 is connected to the elastic wave filter 412, and the other end of the inductor 61 is connected to the input terminal of the low-noise amplifier 21. The inductor 61 can provide impedance matching between the elastic wave filter 412 and the low-noise amplifier 21. The inductor 61 may also be connected between the path connecting the elastic wave filter 412 and the low-noise amplifier 21 and ground.

[0054] The inductor 62 is connected between the elastic wave filter 42 and the low-noise amplifier 22. Specifically, one end of the inductor 62 is connected to the elastic wave filter 42, and the other end of the inductor 62 is connected to the input terminal of the low-noise amplifier 22. The inductor 62 can provide impedance matching between the elastic wave filter 42 and the low-noise amplifier 22. The inductor 62 may also be connected between the path connecting the elastic wave filter 42 and the low-noise amplifier 22 and ground.

[0055] The inductor 63 is connected between the elastic wave filter 43 and the low-noise amplifier 23. Specifically, one end of the inductor 63 is connected to the elastic wave filter 43, and the other end of the inductor 63 is connected to the input terminal of the low-noise amplifier 23. The inductor 63 can provide impedance matching between the elastic wave filter 43 and the low-noise amplifier 23. Alternatively, the inductor 63 may be connected between the path connecting the elastic wave filter 43 and the low-noise amplifier 23 and ground.

[0056] [1.3. Frequency Bands] Next, the frequency bands supported by the high-frequency module 1 according to this embodiment will be described. Bands A, B, and C are frequency bands for communication systems built using Radio Access Technology (RAT). Bands A to C are predefined by standardization organizations (e.g., 3GPP and IEEE). Examples of communication systems include 5GNR (5th Generation New Radio) systems, 4GLTE (4th Generation Long Term Evolution) systems, and 2GGSM (2nd Generation Global System for Mobile communications).

[0057] Band A is an example of a first band, and Bands B and C are examples of second bands, respectively. Bands A and B may be a band combination that allows simultaneous communication. Similarly, Bands A and C may also be a band combination that allows simultaneous communication. In this case, the harmonic band of the transmission band of Band A may overlap at least partially with the reception band of Band C. Examples of such combinations of Bands A to C include (B8, B20, B3), (B8, B20, B41), (B8, B28, B3), (B8, B28, B41), and (B26, B28, B41)(B26, B28, B1), but Bands A to C are not limited to these combinations.

[0058] Note that bands A to C are not limited to the frequency bands included in FR1 (Frequency Range 1). For example, some or all of bands A to C may be frequency bands included in FR3 (Frequency Range 3) (7.125GHz to 24.25GHz) or FR2 (Frequency Range 2) (24.25GHz to 71GHz).

[0059] [1.4. Implementation Example of High-Frequency Module 1] Next, an example of implementing the high-frequency module 1 having the circuit configuration described above will be explained with reference to Figures 2 to 6. Figure 2 is a plan view of the high-frequency module 1 according to this embodiment. Figure 3 is a plan view of the high-frequency module 1 according to this embodiment, and is a view from the positive z-axis side through to the main surface 90b side of the module substrate 90. Figures 4 to 6 are cross-sectional views of the high-frequency module 1 according to this embodiment. The cross-sections of the high-frequency module 1 in Figures 4 to 6 are the cross-sections along the iv-iv, vv, and vi-vi lines in Figures 2 and 3, respectively.

[0060] In Figure 2, to facilitate understanding of the arrangement of each component, the illustration of the resin member 91 covering multiple circuit components and the metal shield 92 covering the resin member 91 is omitted, and each component is labeled. Note that in reality, these labels may not be attached to the individual components. Also, in Figure 2, components hatched with diagonal lines represent optional components not essential to this embodiment.

[0061] Figures 2 to 6 show exemplary implementations of the high-frequency module 1, and the high-frequency module 1 can be implemented using a wide variety of circuit implementations and circuit technologies. Therefore, the description of the high-frequency module 1 provided below should not be interpreted restrictively.

[0062] In addition to the multiple circuit components shown in Figure 2, the high-frequency module 1 includes a module substrate 90, a resin member 91, a metal shield 92, and multiple external connection terminals 93.

[0063] The module substrate 90 has two opposing main surfaces 90a and 90b. The main surfaces 90a and 90b are examples of a first main surface and a second main surface, respectively. Wiring and via conductors (not shown) are formed inside and / or on the module substrate 90.

[0064] As the module substrate 90, for example, a low-temperature co-fired ceramics (LTCC) substrate or a high-temperature co-fired ceramics (HTCC) substrate having a laminated structure of multiple dielectric layers, a component-embedded substrate, a substrate having a redistribution layer (RDL), or a printed circuit board can be used, but is not limited to these.

[0065] The resin member 91 is placed on the main surface 90a of the module substrate 90 and covers at least a portion of the main surface 90a of the module substrate 90 and the components on the main surface 90a. The material of the resin member 91 can be, for example, epoxy resin, but is not limited thereto. The resin member 91 has the function of ensuring the reliability of the components on the main surface 90a, such as mechanical strength and moisture resistance. Note that the resin member 91 does not necessarily have to be included in the high-frequency module 1.

[0066] The metal shield 92 is an example of a second metal shield and is formed on at least a portion of the surface of the resin member. For example, the metal shield 92 is a thin metal film formed on the surface of the resin member 91 by sputtering. In this embodiment, the metal shield 92 covers the top and side surfaces of the resin member 91 and the side surfaces of the module substrate 90. The metal shield 92 is connected to ground and can suppress external noise from entering the electronic components constituting the high-frequency module 1, and from noise generated in the high-frequency module 1 interfering with other modules or other equipment. Note that the metal shield 92 does not necessarily have to be included in the high-frequency module 1.

[0067] The multiple external connection terminals 93 include antenna connection terminals 101 and 102, a high-frequency input terminal 103, and high-frequency output terminals 104 to 106. The multiple external connection terminals 93 are connected to input / output terminals and / or ground terminals, etc., on a mother board (not shown) located in the negative z-axis direction of the high-frequency module 1, outside the high-frequency module 1. In addition, the multiple external connection terminals 93 are connected to electrodes on the main surface 90b of the module board 90 and / or electrodes inside the module board 90, inside the high-frequency module 1.

[0068] The power amplifier circuit 11 (PA) is included in the semiconductor components arranged on the main surface 90a of the module substrate 90. For example, silicon germanium (SiGe) or gallium arsenide (GaAs) can be used as the semiconductor material for the power amplifier circuit 11. In this case, some or all of the transistors included in the power amplifier circuit 11 can be heterojunction bipolar transistors (HBTs). Alternatively, gallium nitride (GaN) or silicon carbide (SiC) can be used as the semiconductor material for the power amplifier circuit 11. In this case, some or all of the transistors included in the power amplifier circuit 11 can be HEMTs (High Electron Mobility Transistors) or MESFETs (Metal-Semiconductor Field Effect Transistors). Alternatively, silicon single crystal (Si) can be used as the semiconductor material for the power amplifier circuit 11. In this case, some or all of the transistors included in the power amplifier circuit 11 may be made of CMOS (Complementary Metal Oxide Semiconductor) and may be manufactured by an SOI (Silicon on Insulator) process. The power amplifier circuit 11 may also be divided and included in multiple semiconductor components.

[0069] The low-noise amplifiers 21-23 (LNAs) are included in the semiconductor components arranged on the main surface 90a of the module substrate 90. For example, silicon single crystal (Si), gallium nitride (GaN), or silicon carbide (SiC) can be used as the semiconductor material for the low-noise amplifiers 21-23. In this case, some or all of the transistors included in the low-noise amplifiers 21-23 can be field-effect transistors (FETs). Bipolar transistors may be used instead of FETs. Furthermore, the low-noise amplifiers 21-23 may be divided and included in multiple semiconductor components.

[0070] The transformer 31 is placed inside the module board 90. A detailed example of the transformer 31's implementation will be described later with reference to the drawings.

[0071] Each of the elastic wave filters 411 (A-Tx) and 412 (A-Rx) is arranged on the main surface 90a of the module substrate 90 and includes a surface acoustic wave (SAW) filter and / or a bulk acoustic wave (BAW) filter. The elastic wave filters 411 and / or 412 may further include an LC filter or a dielectric filter. The elastic wave filters 411 and 412 are a duplexer 41 formed on the same piezoelectric substrate. A ground-connected metal film is formed on the side surface of the duplexer 41 as a metal shield S1.

[0072] The metal shield S1 is an example of a first metal shield and is positioned between the transformer 31 and the inductor 61 in a plan view of the module substrate 90. As shown in Figure 4, the metal shield S1 is electrically connected by physically contacting the metal shield 92 formed on the surface of the resin member 91. In Figure 2, the metal shield S1 is formed on the entire side surface of the duplexer 41, but it may be formed on only a part of the side surface of the duplexer 41. Furthermore, the metal shield S1 does not have to be in physical contact with the metal shield 92, nor is it electrically connected. Also, the elastic wave filters 411 and 412 do not have to be formed on the same piezoelectric substrate, and they do not have to be duplexers.

[0073] The elastic wave filter 42 (B-Rx) is disposed on the main surface 90a of the module substrate 90 and includes a SAW filter and / or a BAW filter. The elastic wave filter 42 may further include an LC filter or a dielectric filter. A ground-connected metal film is formed on the side surface of the elastic wave filter 42 as a metal shield S2.

[0074] The metal shield S2 is an example of a first metal shield and is positioned between the transformer 31 and the inductor 62 in a plan view of the module substrate 90. As shown in Figure 5, the metal shield S2 is electrically connected to the metal shield 92 by physical contact. In Figure 2, the metal shield S2 is formed on all sides of the elastic wave filter 42, but it may be formed on only a portion of the sides of the elastic wave filter 42. Furthermore, the metal shield S2 does not need to be in physical contact with the metal shield 92, nor does it need to be electrically connected.

[0075] The elastic wave filter 43 (C-Rx) is disposed on the main surface 90a of the module substrate 90 and includes a SAW filter and / or a BAW filter. The elastic wave filter 43 may further include an LC filter or a dielectric filter. A ground-connected metal film is formed on the side surface of the elastic wave filter 43 as a metal shield S3.

[0076] The metal shield S3 is an example of a first metal shield and is positioned between the transformer 31 and the inductor 63 in a plan view of the module substrate 90. As shown in Figure 6, the metal shield S3 is electrically connected to the metal shield 92 by physical contact. In Figure 2, the metal shield S3 is formed on all sides of the elastic wave filter 43, but it may be formed on only a portion of the sides of the elastic wave filter 42. Furthermore, the metal shield S3 does not need to be in physical contact with the metal shield 92, nor does it need to be electrically connected.

[0077] In this embodiment, metal shields are formed on the duplexer 41 and on each of the acoustic wave filters 42 and 43. However, metal shields may be formed on only one of the duplexer 41 and the acoustic wave filters 42 and 43, or on any two of them.

[0078] The switch circuit 51 (ASW) is included in the semiconductor components arranged on the main surface 90a of the module substrate 90. For example, silicon single crystal (Si), gallium nitride (GaN), or silicon carbide (SiC) can be used as the semiconductor material for the switch circuit 51. In this case, some or all of the transistors included in the switch circuit 51 can be field-effect transistors (FETs). Bipolar transistors may be used instead of FETs. Furthermore, the switch circuit 51 may be divided and included in multiple semiconductor components.

[0079] Inductors 61-63(L) are mounted as chip inductors on the main surface 90a of the module board 90. A chip inductor refers to a discrete surface mount device (SMD) that constitutes an inductor. Note that inductors 61-63 are not limited to chip inductors. For example, some or all of inductors 61-63 may be formed by wiring on or within the module board 90, or may be included in an integrated passive device (IPD).

[0080] [1.5. Implementation Example of Transformer 31] Next, an example of mounting the transformer 31 formed within the module substrate 90 will be described with reference to Figures 7A, 7B, 7C, and 8.

[0081] Figures 7A to 7C are plan views of the transformers 31 in layers L1 to L3 of the module board 90 according to this embodiment. Figure 8 is a plan view of the transformers 31 in layers L2 and L3 of the module board 90 according to this embodiment. In Figure 8, the wiring W22 on layer L3 is represented by a dashed line.

[0082] Figures 7A to 7C and Figure 8 show exemplary implementations of the transformer 31, and the transformer 31 can be implemented using a wide variety of circuit implementations and circuit technologies. Therefore, the description of the transformer 31 provided below should not be interpreted restrictively.

[0083] The module substrate 90 includes layers L1 to L3 in order from the main surface 90a side. In other words, layers L1 to L3 are closer to the main surface 90a of the module substrate 90 in this order. In this embodiment, layer L1 is the outer layer, i.e., the main surface 90a, but is not limited to this. In other words, layers L1 to L3 may all be inner layers.

[0084] The primary coil 311 of the transformer 31 is formed from the wiring W1 on layer L2. Specifically, the primary coil 311 is formed from the C-shaped portion of the wiring W1 on layer L2 that overlaps with wirings W21 and W22 in a plan view of the module substrate 90. As mentioned above, the C-shape does not necessarily represent only a strictly C-shape. For example, the C-shape may be a shape formed by a combination of straight and curved sections, as shown in Figures 7B and 8. Furthermore, the C-shape may also include U-shapes and / or V-shapes.

[0085] One end of wiring W1 is connected to a terminal of the power amplifier circuit 11 via a via conductor, and the other end of wiring W1 is connected to another terminal of the power amplifier circuit 11 via a via conductor. A power supply voltage (Vcc) is applied to the intermediate node M1 of the primary coil 311 by a power supply (not shown).

[0086] As shown in Figure 8, in a plan view of the module board 90, the perpendicular bisector PB1 of the imaginary line segment LS1 connecting both ends of the primary coil 311 (one end E11 and the other end E12) does not intersect with the inductors 61-63. Note that one end E11 and the other end E12 of the primary coil 311 are defined by the ends of the portion of wiring W1 that overlaps with wirings W21 and W22 in a plan view of the module board 90.

[0087] The secondary coil 312 of the transformer 31 is formed by wiring W21 on layer L1 and wiring W22 on layer L3. Specifically, the secondary coil 312 is formed by the portions of wiring W21 and W22 on layers L1 and L3 that overlap with wiring W1 in a plan view of the module substrate 90. One end of wiring W21 is connected to the elastic wave filter 411. One end of wiring W22 is connected via a via conductor to a ground terminal (at least one of a plurality of external connection terminals 93) located on the main surface 90b of the module substrate 90. The other end of wiring W21 and the other end of wiring W22 are intermediate nodes M2 of the secondary coil 312 and are connected to each other via via conductors.

[0088] In this implementation example, the primary coil 311 is formed by wiring W1 on one layer L2, and the secondary coil 312 is formed by wiring W21 and W22 on two layers L1 and L3. However, the number of wiring layers on which the primary coil 311 and secondary coil 312 are formed is not limited to this. For example, the secondary coil 312 may be formed by wiring on one layer. Also, the transformer 31 may be implemented as an SMD.

[0089] [1.6. Summary] As described above, the high-frequency module 1 according to this embodiment includes a module board 90, two power amplifiers 111 and 112 arranged on the module board 90, a first elastic wave filter (e.g., elastic wave filter 411) arranged on the module board 90 and connected to the output terminals of the two power amplifiers 111 and 112, a low-noise amplifier 21, 22 or 23 arranged on the module board 90, a second elastic wave filter (e.g., elastic wave filters 412, 42 or 43) arranged on the module board 90 and connected to the input terminals of the low-noise amplifiers 21, 22 or 23, and a primary coil 311 and a secondary coil 312 formed by wiring on multiple layers of the module board 90. The module board 90 comprises a transformer 31, a primary coil 311 with both ends connected to the output terminals of two power amplifiers 111 and 112, and a secondary coil 312 with one end connected to a first elastic wave filter, and inductors 61, 62, or 63 arranged on the module board 90 and connected between the second elastic wave filter and the low-noise amplifiers 21, 22, or 23. A metal shield S1, S2, or S3 is formed on at least a portion of one side of at least one of the first and second elastic wave filters, and in a plan view of the module board 90, the metal shield S1, S2, or S3 is arranged between the transformer 31 and the inductors 61, 62, or 63.

[0090] According to this, the metal shield S1, S2, or S3 formed on at least a portion of the side surface of at least one of the first and second elastic wave filters can improve the isolation between the transformer 31 and the inductors 61, 62, or 63. In particular, since the inductors 61, 62, and 63 are easily coupled to the transformer 31, the effect of improving isolation by the metal shield S1, S2, or S3 is significant. Furthermore, since the metal shield S1, S2, or S3 is formed on the side surface of the elastic wave filter, the high-frequency module 1 can be made smaller than when a separate metal shield wall is arranged on the module substrate 90 in addition to the elastic wave filter. As described above, the high-frequency module 1 can be made smaller and the isolation between components can be improved.

[0091] For example, in the high-frequency module 1 according to this embodiment, the first elastic wave filter may be an elastic wave filter 411 having a passband that includes the transmission band of FDD band A, and the second elastic wave filter may be an elastic wave filter 412 having a passband that includes the reception band of FDD band A.

[0092] According to this, the metal shield S1 formed on at least a portion of the side surface of the elastic wave filter 411 or 412 can improve the isolation between transmission and reception in FDD band A. As a result, the decrease in reception sensitivity of band A can be suppressed in frequency division duplexing of band A.

[0093] Furthermore, for example, in the high-frequency module 1 according to this embodiment, the elastic wave filters 411 and 412 may be formed on the same piezoelectric substrate.

[0094] According to this, the transmit filter and receive filter for FDD band A can be formed on the same piezoelectric substrate, and the high-frequency module 1 can be miniaturized.

[0095] For example, in the high-frequency module 1 according to this embodiment, the first elastic wave filter may be an elastic wave filter 411 having a passband that includes the transmission band of band A, and the second elastic wave filter may be an elastic wave filter 42 or 43 having a passband that includes the reception band of band B or C, and band A and band B or C may be a band combination that enables simultaneous communication.

[0096] According to this, the metal shield S2 or S3 formed on at least a portion of the side surface of the elastic wave filter 42 or 43 can improve the isolation between the transmission in band A and the reception in band B or C. As a result, when simultaneously transmitting and receiving signals in band A and band B or C, the decrease in the receiving sensitivity of band B or C can be suppressed.

[0097] Furthermore, for example, in the high-frequency module 1 according to this embodiment, the harmonic band of the transmission band of band A may overlap at least partially with the reception band of band C.

[0098] According to this, the metal shield S3 formed on at least a portion of the side surface of the elastic wave filter 43 can improve the isolation between the transmission in band A and the reception in band C. As a result, in simultaneous transmission and reception of the transmission signal in band A and the reception signal in band C, it is possible to suppress the decrease in the reception sensitivity of band C due to harmonics of the transmission signal in band A.

[0099] For example, the high-frequency module 1 according to this embodiment may further include a resin member 91 disposed on a module substrate 90 and a metal shield 92 formed on at least a part of the surface of the resin member 91, and the metal shield S1, S2, or S3 may be electrically connected to the metal shield 92.

[0100] According to this, the metal shield 92 formed on the surface of the resin member 91 is electrically connected to the metal shield S1, S2, or S3, so that the transformer 31 can be suppressed from magnetically coupling (inductive coupling) with the inductor 61, 62, or 63 via the metal shield 92.

[0101] Furthermore, for example, in the high-frequency module 1 according to this embodiment, the metal shields S1, S2, or S3 may be arranged to be in physical contact with the metal shield 92.

[0102] According to this, the metal shield 92 formed on the surface of the resin member 91 is in physical contact with the metal shield S1, S2, or S3, so that the transformer 31 can be prevented from magnetically coupling (inductively coupling) with the inductor 61, 62, or 63 via the metal shield 92.

[0103] For example, in the high-frequency module 1 according to this embodiment, the primary coil 311 may be formed in a C shape in a plan view of the module substrate 90, and the perpendicular bisector PB1 of the imaginary line segment LS1 connecting one end E11 and the other end E12 of the primary coil 311 may be arranged so as not to intersect with the inductors 61, 62, or 63.

[0104] According to this, the C-shaped opening of the primary coil 311, which generates a stronger magnetic field, is prevented from being directed towards the inductors 61, 62, or 63, thereby further suppressing the coupling between the transformer 31 and the inductors 61, 62, or 63.

[0105] (modified version) Next, a modified version of the embodiment will be described. In this modified version, the metal shield formed on the side surface of the elastic wave filter is electrically connected to the metal shield formed on the surface of the resin member via metal electrodes placed in holes in the resin member. The following description of this modified version will focus on the differences from the above embodiment, with reference to the drawings.

[0106] The circuit configuration and plan view of the communication device 5 and high-frequency module 1 in this modified example are the same as those of the high-frequency module 1 in the above embodiment, so their illustration and description are omitted.

[0107] [2.1. Implementation Example of High-Frequency Module 1] Figure 9 is a partial cross-sectional view of the high-frequency module 1 according to this modified example. The cross-section of the high-frequency module 1 according to this modified example in Figure 9 corresponds to the portion of the duplexer 41 in the cross-section of the high-frequency module 1 according to the embodiment in Figure 4.

[0108] Figure 9 shows an exemplary implementation of the high-frequency module 1 according to this modified example, and the high-frequency module 1 can be implemented using a wide variety of circuit implementations and circuit technologies. Therefore, the description of the high-frequency module 1 provided below should not be interpreted as restrictive.

[0109] In this modified example, the metal shield S1 is formed on the top surface of the duplexer 41 in addition to the side surface. However, the metal shield S1 does not need to be formed on the entire top surface of the duplexer 41; it may be formed on only a portion of the top surface of the duplexer 41.

[0110] A hole 911 reaching the metal shield S1 is formed on the surface of the resin member 91. A metal electrode 921 is placed in the hole 911 to electrically connect the metal shield S1 to the metal shield 92. In other words, the metal shield S1 is electrically connected to the metal shield S1 via the metal electrode 921. The metal electrode 921 is, for example, a thin metal film formed on the side wall of the hole 911, but is not limited to this.

[0111] In addition, metal shields S2 and S3 may also be connected to metal shield 92 via metal electrodes 921 placed in holes 911 of resin member 91, similar to metal shield S1.

[0112] [2.2. Summary] As described above, in the high-frequency module 1 according to this modified example, the metal shield S1, S2, or S3 may further be formed on the top surface of at least one of the elastic wave filters 411, 412, 42, and 43, and a hole 911 reaching the metal shield S1, S2, or S3 may be formed on the surface of the resin member 91, and the metal shield S1, S2, or S3 may be electrically connected to the metal shield 92 via a metal electrode 921 placed in the hole 911.

[0113] According to this, even if the height of the elastic wave filters 411, 412, 42, and 43 is low, the metal shields S1, S2, or S3 can be electrically connected to the metal shield 92.

[0114] (Other embodiments) The high-frequency module according to the present invention has been described above based on embodiments, but the high-frequency module according to the present invention is not limited to the above embodiments. Other embodiments realized by combining any of the components in the above embodiments, modified versions obtained by applying various modifications to the above embodiments that a person skilled in the art can conceive without departing from the spirit of the present invention, and various devices incorporating the above high-frequency module are also included in the present invention.

[0115] For example, in the circuit configuration of the high-frequency module according to the above embodiment, other circuit elements and wiring may be inserted between the paths connecting each circuit element and signal path disclosed in the drawings. For example, an impedance matching circuit may be connected between the transformer 31 and the elastic wave filter 411, and / or between the elastic wave filters 411, 412, and 42 and the switch circuit 51. Alternatively, for example, a coupler may be connected between the switch circuit 51 and the antenna connection terminals 101 and / or 102. [Industrial applicability]

[0116] This invention can be widely used in communication devices such as mobile phones as a high-frequency module positioned in the front end. [Explanation of Symbols]

[0117] 1. High-frequency module 2a, 2b antennas 3RFIC 4 BBIC 5. Communication equipment 11 Power Amplifier Circuit 21, 22, 23 Low-noise amplifier 31, 114 Transformers 41 Duplexa 42, 43, 411, 412 Elastic wave filters 51 Switch Circuit 61, 62, 63 Inductors 90 Module boards 90a, 90b main surface 91 Resin component 92, S1, S2, S3 Metal Shield 93 External connection terminals 101, 102 Antenna connection terminals 103 High-frequency input terminal 104, 105, 106 High-frequency output terminals 111, 112, 113 Power amplifiers 311, 1141 Primary coil 312, 1142 Secondary coil 511, 512 Common terminal 513, 514 Select terminals 911 holes 921 Metal electrode E11 One end of the primary coil E12 Other end of primary coil L1, L2, L3 layers LS1 virtual line segment M1, M2 intermediate nodes PB1 Perpendicular bisector W1, W21, W22 wiring

Claims

1. Module board and Two power amplifiers arranged on the aforementioned module board, A first elastic wave filter is placed on the module board and connected to the output terminals of the two power amplifiers, A low-noise amplifier arranged on the module board, A second elastic wave filter is placed on the module board and connected to the input terminal of the low-noise amplifier, A transformer including a primary coil and a secondary coil formed by wiring on multiple layers of the module board, the ends of the primary coil connected to the output terminals of the two power amplifiers, and one end of the secondary coil connected to the first elastic wave filter. The module board is arranged and includes an inductor connected between the second elastic wave filter and the low-noise amplifier, A first metal shield is formed on at least a portion of at least one side of the first elastic wave filter and the second elastic wave filter. In a plan view of the module substrate, the first metal shield is positioned between the transformer and the inductor. High-frequency module.

2. The first elastic wave filter is a filter having a passband that includes the transmission band of the FDD band, The second elastic wave filter is a filter having a passband that includes the receiving band of the FDD band. The high-frequency module according to claim 1.

3. The first elastic wave filter and the second elastic wave filter are formed on the same piezoelectric substrate. The high-frequency module according to claim 2.

4. The first elastic wave filter is a filter having a passband that includes the transmission bandwidth of the first band, The second elastic wave filter is a filter having a passband that includes the receiving band of the second band, The first band and the second band are a band combination that allows simultaneous communication. The high-frequency module according to claim 1.

5. The harmonic bandwidth of the transmission bandwidth of the first band overlaps at least partially with the reception bandwidth of the second band. The high-frequency module according to claim 4.

6. The aforementioned high-frequency module further, A resin member disposed on the module substrate, The resin member comprises a second metal shield formed on at least a portion of its surface, The first metal shield is electrically connected to the second metal shield. A high-frequency module according to any one of claims 1 to 5.

7. The first metal shield is positioned to be in physical contact with the second metal shield. The high-frequency module according to claim 6.

8. The first metal shield is further formed on the top surface of at least one of the first elastic wave filter and the second elastic wave filter. The surface of the resin member has holes that reach the first metal shield. The first metal shield is electrically connected to the second metal shield via metal electrodes placed in the holes. The high-frequency module according to claim 6.

9. In a plan view of the module substrate, the primary coil is formed in a C shape, and is positioned such that the perpendicular bisector of the imaginary line segment connecting both ends of the primary coil does not intersect the inductor. A high-frequency module according to any one of claims 1 to 8.

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