RADIO FREQUENCY MODULE AND COMMUNICATION DEVICE

A radio frequency module includes submodules and a connection board that connects the submodule and the submodule. The submodule includes a module board and a first component arranged on the module board, the submodule includes a module board and a second component arranged on the module board, and the connection board is directly connected to the module boards and electrically connects the first component and the second component.

BACKGROUND OF THE DISCLOSURE

Field of the Disclosure

The present disclosure relates to radio frequency modules and communication devices.

Description of the Related Art

In mobile communication devices such as cellular phones and the like, particularly, with the development of multiband systems, the number of circuit elements that make up a radio frequency front-end circuit is increasing.

Patent Document 1 discloses a radio frequency module (electronic component module) in which the electronic components making up a radio frequency front-end circuit are mounted on both sides of a circuit board. The electronic components mounted on the circuit board are covered with a sealing resin layer, and connection terminals (pad electrodes) are formed on the surface of this sealing resin layer for the connection with an external board (mounting board).

Patent Document 1: Japanese Unexamined Patent

BRIEF SUMMARY OF THE DISCLOSURE

However, in a radio frequency module having the configuration in which a plurality of the electronic component modules (submodules) disclosed in Patent Document 1 are mounted on a mounting board, when electronic components arranged in different submodules are electrically connected via the mounting board, a connection wiring line connecting these electronic components becomes longer, and this leads to the issue of an increase in transmission loss of a radio frequency signal.

The present disclosure is made to resolve the foregoing issue, and a possible benefit thereof is to provide a radio frequency module and a communication device, each of which enables the reduction of transmission loss of a plurality of submodules arranged on a mounting board.

A radio frequency module according to one aspect of the present disclosure includes a first module, a second module, and a connection board that connects the first module and the second module. The first module includes a first module board and a first component arranged on the first module board, the second module includes a second module board and a second component arranged on the second module board, and the connection board is directly connected to the first module board and the second module board and electrically connects the first component and the second component.

According to the present disclosure, it becomes possible to provide a radio frequency module and a communication device, each of which enables the reduction of transmission loss of a plurality of submodules arranged on a mounting board.

DETAILED DESCRIPTION OF THE DISCLOSURE

Hereinafter, embodiments of the present disclosure will be described in detail. Note that the embodiments, which will be described below, each illustrate a comprehensive or specific example. Numeric values, shapes, materials, constituent elements, arrangements and connection modes of the constituent elements, and the like illustrated in the following embodiments are mere examples, and not intended to limit the present disclosure. Of constituent elements in the following working example and modified example, the constituent elements that are not described in an independent claim will be described as optional constituent elements. Further, sizes or ratios of the sizes of constituent elements illustrated in the drawings are not necessarily exact ones. In the respective drawings, same reference characters are attached to substantially the same constituent elements, and in some cases, overlapping descriptions are omitted or simplified.

Further, in the following section, terms indicating relationships among elements such as “parallel”, “vertical”, and the like, terms indicating shapes of elements such as “rectangle” and the like, and numerical ranges are used not only to represent their precise meanings but also include their substantially equivalent ranges, for example, variations of about few %.

Further, in the following section, with regard to A, B, and C mounted on a board, “C is arranged between A and B in the plan view of the board (or a principal surface of the board)” is defined to mean that in the plan view of the board, at least one of a plurality of line segments each connecting an arbitrary point within A and an arbitrary point within B passes through an area of C. Further, the plan view of a board is defined to mean that the board and circuit elements mounted on the board are projected orthographically onto a plane parallel to a principal surface of the board for viewing.

Further, in the following section, “A is arranged on a first principal surface of a board” is defined to mean not only the case where A is directly mounted on the first principal surface but also the case where, of a space on the first principal surface side and a space on the second principal surface side, which are divided by the board, A is arranged in the space on the first principal surface side. That is to say, “A is arranged on a first principal surface of a board” also includes the case where A is mounted on the first principal surface with another circuit element, an electrode, or the like interposed therebetween.

Further, in the following section, a “transmit path” is defined to mean a transmission line made up of a wiring line that transmits a radio frequency transmit signal, an electrode directly connected to this wiring line, a terminal directly connected to this wiring line or this electrode, and the like. Further, a “receive path” is defined to mean a transmission line made up of a wiring line that transmits a radio frequency receive signal, an electrode directly connected to this wiring line, a terminal directly connected to this wiring line or this electrode, and the like. Further, a “signal path” is defined to mean a transmission line made up of a wiring line that transmits a radio frequency signal, an electrode directly connected to this wiring line, a terminal directly connected to this wiring line or this electrode, and the like.

Embodiment

1. Circuit Configuration of Radio Frequency Module1and Communication Device4

FIG.1is a circuit configuration diagram of a radio frequency module1and a communication device4according to an embodiment. As illustrated inFIG.1, the communication device4includes the radio frequency module1, antennas2A and2B, and RF signal processing circuits (RFICs)3A and3B. The radio frequency module1includes submodules10and20.

The RFICs3A and3B are RF signal processing circuits that perform processing on radio frequency signals being transmitted and received by the antennas2A and2B. Specifically, the RFIC3A performs signal processing such as down-converting and the like on a receive signal inputted via a receive path of the submodule10, and outputs a receive signal generated by this signal processing to a baseband signal processing circuit (not illustrated). Further, the RFIC3A performs signal processing such as up-converting and the like on a transmit signal inputted from the baseband signal processing circuit, and outputs a transmit signal generated by this signal processing to a transmit path of the submodule10. Further, the RFIC3B performs signal processing such as down-converting and the like on a receive signal inputted via a receive path of the submodule20, and outputs a receive signal generated by this signal processing to the baseband signal processing circuit (not illustrated). Further, the RFIC3B performs signal processing such as up-converting and the like on a transmit signal inputted from the baseband signal processing circuit, and outputs a transmit signal generated by this signal processing to a transmit path of the submodule20.

Further, the RFIC3A functions as a control unit that controls the connections of switches11and12included in the submodule10based on the communication band (frequency band) to be used, the antenna sensitivity, and the like. Further, the RFIC3B functions as a control unit that controls the connections of switches21and22included in the submodule20based on the communication band (frequency band) to be used, the antenna sensitivity, and the like.

Further, the RFIC3A also functions as a control unit that controls the gain of a power amplifier14T included in the submodule10and a power voltage Vcc and a bias voltage Vbias to be supplied to the power amplifier14T. Further, the RFIC3B also functions as a control unit that controls the gain of a power amplifier24T included in the submodule20and a power voltage Vcc and a bias voltage Vbias to be supplied to the power amplifier24T.

Note that the foregoing control units may be provided outside the RFICs3A and3B.

The antenna2A is connected to an antenna connection terminal110of the submodule10, emits a radio frequency signal outputted from the submodule10or20, and receives a radio frequency signal from outside and outputs the received radio frequency signal to the submodule10or20. The antenna2B is connected to an antenna connection terminal120of the submodule20, emits a radio frequency signal outputted from the submodule10or20, and receives a radio frequency signal from outside and outputs the received radio frequency signal to the submodule10or20.

Note that in the communication device4according to the present embodiment, the antennas2A and2B are not essential constituent elements.

Next, the configuration of the radio frequency module1is described below in detail.

The submodule10is one example of a first module and includes the antenna connection terminal110, a transmit input terminal111, a receive output terminal112, the switches11and12, a duplexer13, the power amplifier14T, and a low-noise amplifier14R.

The submodule20is one example of a second module and includes the antenna connection terminal120, a transmit input terminal121, a receive output terminal122, the switches21and22, a duplexer23, the power amplifier24T, and a low-noise amplifier24R.

The antenna terminal110is one example of a first antenna connection terminal and is connected to the antenna2A and the switch11. The antenna terminal120is one example of a second antenna connection terminal and is connected to the antenna2B and the switch21.

The power amplifier14T is an amplifier that amplifies a radio frequency signal of a first communication band inputted from the transmit input terminal111. Further, the power amplifier24T is an amplifier that amplifies a radio frequency signal of a second communication band inputted from the transmit input terminal121.

The low-noise amplifier14R is an amplifier that amplifies a radio frequency signal of the first communication band with low noise and outputs this amplified signal to the receive output terminal112. Further, the low-noise amplifier24R is an amplifier that amplifies a radio frequency signal of the second communication band with low noise and outputs this amplified signal to the receive output terminal122.

The duplexer13is made up of a transmit filter13T and a receive filter13R. The transmit filter13T is one example of a first filter and is connected between the switch12and the power amplifier14T. Further, the receive filter13R is one example of the first filter and is connected between the switch12and the low-noise amplifier14R.

The duplexer23is made up of a transmit filter23T and a receive filter23R. The transmit filter23T is one example of a second filter and is connected between the switch22and the power amplifier24T. Further, the receive filter23R is one example of the second filter and is connected between the switch22and the low-noise amplifier24R.

The switch11is one example of a first antenna switch and includes a common terminal11aand selection terminals11b,11c, and11d. The common terminal11ais connected to the antenna connection terminal110, the selection terminal11cis connected to the switch12, and the selection terminal11dis connected to the switch22. According to this, the switch11switches between connecting and disconnecting the antenna connection terminal110to and from the switch12, and switches between connecting and disconnecting the antenna connection terminal110to and from the switch22.

The switch21is one example of a second antenna switch and includes a common terminal21aand selection terminals21b,21c, and21d. The common terminal21ais connected to the antenna connection terminal120, the selection terminal21bis connected to the switch12, and the selection terminal21cis connected to the switch22. According to this, the switch21switches between connecting and disconnecting the antenna connection terminal120to and from the switch22, and switches between connecting and disconnecting the antenna connection terminal120to and from the switch21.

The switches11and21are each made up of, for example, a multi-connection type switch circuit. Note that the numbers of the selection terminals of the switches11and21are appropriately determined based on the number of communication bands to be handled by the submodules10and20.

The switch12is one example of a first switch and includes a common terminal12aand selection terminals12band12c. The common terminal12ais connected to the duplexer13, the selection terminal12bis connected to the selection terminal11c, and the selection terminal12cis connected to the selection terminal21b. According to this, the switch12switches between connecting the duplexer13to the switch11and connecting the duplexer13to the switch21.

The switch22is one example of the second switch and includes a common terminal22aand selection terminals22band22c. The common terminal22ais connected to the duplexer23, the selection terminal22bis connected to the selection terminal11d, and the selection terminal22cis connected to the selection terminal21c. According to this, the switch22switches between connecting the duplexer23to the switch11and connecting the duplexer23to the switch21.

The switches12and22are each made up of, for example, a SPDT (Single Pole Double Throw) type switch circuit.

The selection terminal11dof the switch11is connected to the selection terminal22bof the switch22via a wiring line31. Further, the selection terminal12cof the switch12is connected to the selection terminal21bof the switch21via a wiring line32.

Note that each of the duplexers13and23may alternatively be a single filter for transmission using a time division duplex (TDD) system. In this case, the foregoing single filter is preceded, followed, or preceded and followed by a switch that switches between transmitting and receiving.

Further, an impedance matching circuit may be inserted between the antenna connection terminal110, the switch11, the switch12, the duplexer13, the power amplifier14T and the low-noise amplifier14R, and the transmit input terminal111and the receive output terminal112, which make up the submodule10. Further, an impedance matching circuit may be inserted between the antenna connection terminal120, the switch21, the switch22, the duplexer23, the power amplifier24T and the low-noise amplifier24R, and the transmit input terminal121and the receive output terminal122, which make up the submodule20.

Note that the low-noise amplifier14R and the switches11and12may be formed in a first semiconductor IC (Integrated Circuit). Further, the low-noise amplifier24R and the switches21and22may be formed in a second semiconductor IC. Each of the first semiconductor IC and the second semiconductor IC is, for example, composed of CMOS. Specifically, each of the first semiconductor IC and the second semiconductor IC is formed by a SOI (Silicon On Insulator) process. Note that the first semiconductor IC and the second semiconductor IC may be composed of at least one of GaAs, SiGe, and GaN. Because of this, it becomes possible to output a radio frequency signal with high quality amplification performance and noise performance.

Note that of the switch11, the switch12, the duplexer13, the power amplifier14T, and the low-noise amplifier14R, the submodule10according to the present disclosure only needs to include two circuit components (first component and fourth component). Further, of the switch21, the switch22, the duplexer23, the power amplifier24T, and the low-noise amplifier24R, the submodule20according to the present disclosure only needs to include one circuit component (second component). At this time, it is only necessary that the first component of the submodule10and the second component of the submodule20are directly connected via a first wiring line.

Here, with the configuration in which the submodules10and20are arranged on a mounting board, when the submodules10and20are electrically connected via the mounting board, connection wiring lines connecting the submodules10and20become longer, and this leads to the issue of an increase in transmission loss of a radio frequency signal.

In contrast, in the radio frequency module1according to the present embodiment, the configuration in which the submodules10and20are arranged on the mounting board has a configuration that reduces the transmission loss of the radio frequency module1. In the following section, the configuration that reduces the transmission loss of the radio frequency module1according to the present embodiment is described.

2. Exemplary Configuration of Communication Device4According to Embodiment

FIG.2is a diagram illustrating an exemplary configuration of the communication device4according to the embodiment. The communication device4illustrated inFIG.2depicts, for example, a mobile terminal. As illustrated inFIG.2, the antennas2A and2B are arranged on the top left corner and the top right corner of the mobile terminal, respectively. In addition to the submodules10and20, the radio frequency module1further includes a mounting board91. The submodules10and20are arranged on the mounting board91and connected to each other via wiring lines31and32. The RFIC3A and the antenna2A are connected to the submodule10, and the RFIC3B and the antenna2B are connected to the submodule20. Note that the RFICs3A and3B may be arranged on the mounting board91.

Here, the wiring lines31and32are arranged in such a manner as to be separated from the mounting board91.

With the foregoing configuration, the submodule10and the submodule20are directly connected to the wiring lines31and32, and thus the wiring lines that connect the submodule10and the submodule20can be shortened compared with the case where the submodule10and the submodule20are electrically connected via the mounting board91. Accordingly, the transmission loss of a radio frequency signal being transmitted between the submodule10and the submodule20can be reduced. In the following section, the layout configuration of the mounting board91, the submodules10and20, and the wiring lines31and32is described in detail.

Note that “the submodule10and the submodule20are directly connected to the wiring line31” is defined to mean that the submodule10and the submodule20are connected to each other via the wiring line31without involving a circuit component or a board other than a connection board30. Further, “the submodule10and the submodule20are directly connected to the wiring line31” is defined to include the case where the submodule10and the submodule20are connected to each other via electrodes and terminals connected to the end portions of the wiring line31.

Further, “the submodule10and the submodule20are directly connected to the wiring line32” is defined to mean that the submodule10and the submodule20are connected to each other via the wiring line32without involving a circuit component and a board other than the connection board30. Further, “the submodule10and the submodule20are directly connected to the wiring line32” is defined to include the case where the submodule10and the submodule20are connected to each other via electrodes and terminals connected to the end portions of the wiring line32.

Further, “a module board81and a module board82are directly connected to the connection board30” is defined to mean that the module board81and the module board82are connected to each other via the connection board30without involving a circuit component and a board other than the connection board30. Further, “the module board81and the module board82are directly connected to the connection board30” is defined to include the case where the module board81and the module board82are connected to each other via electrodes and terminals connected to the end portions of the connection board30.

3. Circuit Element Layout Configuration of Radio Frequency Module1A According to Working Example

FIG.3is a plan view of schematic configuration of a radio frequency module1A according to a working example. Further,FIG.4is a sectional view of schematic configuration of the radio frequency module1A according to the working example, and specifically, a sectional view at line IV-IV ofFIG.3. Note that inFIG.3, a layout diagram of circuit elements is illustrated when, of opposing principal surfaces91aand91bof the mounting board91, the principal surface91ais seen from a positive direction side of z-axis, and a diagram in which circuit components arranged on the module boards81and82are seen through from the positive direction side of z-axis is illustrated. Note that the circuit components arranged on the principal surface81aside of the module board81and the circuit components arranged on the principal surface82aside of the module board82are shown in the solid lines, and the circuit components arranged on the principal surface81bside of the module board81and the circuit components arranged on the principal surface82bside of the module board82are shown in the dashed lines. Further, inFIG.3, for facilitating the understanding of spatial relationships between the respective circuit components, marks representing their functions are attached to the respective circuit components. However, such marks are not attached in an actual radio frequency module1A.

The radio frequency module1A according to the working example is the one in which the layout configuration of the respective circuit components that make up the radio frequency module1according to the embodiment is specified.

As illustrated inFIG.3andFIG.4, in addition to the circuit configuration illustrated inFIG.1, the radio frequency module1A according to the present working example further includes the module boards81and82, connection board30, connection terminals150, resin members85to88, metal shield layers96,97, and98, and circuit components41to48. In addition to the circuit configuration illustrated inFIG.1, the submodule10further includes the module board81, the connection terminals150, the resin members85and86, and the metal shield layer96. In addition to the circuit configuration illustrated inFIG.1, the submodule20further includes the module board82, the connection terminals150, the resin members87and88, and the metal shield layer97.

The mounting board91has the principal surface91aand the principal surface91b, which face each other, and is a board on which the submodules10and20are mounted. As the mounting board91, for example, a low temperature co-fired ceramics (LTCC) board, a high temperature co-fired ceramics (HTCC) board, a board with built-in components, a board including a redistribution layer (RDL), a printed board, or the like, each of which has a multilayer structure including a plurality of dielectric layers, may be used.

The submodules10and20are arranged on the principal surface91aof the mounting board91.

Note that the radio frequency module1A may include the mounting board91.

The module board81is one example of a first module board, has the principal surface81a(first principal surface) and the principal surface81b(second principal surface), which face each other, and is a board on which the circuit components that make up the submodule10are mounted. The module board82is one example of a second module board, has the principal surface82aand the principal surface82b, which face each other, and is a board on which the circuit components that make up the submodule20are mounted. As the module boards81and82, for example, a LTCC board, a HTCC board, a board with built-in components, a board including an RDL, a printed board, or the like, each of which has a multilayer structure including a plurality of dielectric layers, may be used.

The connection board30is the board that connects the submodule10and the submodule20. The connection board30has two principal surfaces that face each other. As the connection board30, for example, a LTCC board, a HTCC board, a board with built-in components, a board including an RDL, a printed board, or the like, each of which has a multilayer structure including a plurality of dielectric layers, may be used. In the inside of the connection board30, the wiring line31and the wiring line32(first wiring line) that connect a first component of the submodule10and a second component of the submodule20are formed. Further, the metal shield layer98is formed on each of the two principal surfaces of the connection board30, which face each other.

Note that “in the inside of the connection board30, the wiring line31and the wiring line32are formed” is defined to mean that the wiring line31and the wiring line32are formed in a region sandwiched between the two metal shield layers98that face each other.

Note that the antenna connection terminal110, the transmit input terminal111, and the receive output terminal112may be formed on the module board81. Further, the antenna connection terminal120, the transmit input terminal121, and the receive output terminal122may be formed on the module board82.

The resin member85is arranged on the principal surface81aof the module board81and covers part of the circuit components that make up the submodule10and the principal surface81a. The resin member86is arranged on the principal surface81bof the module board81and covers part of the circuit components that make up the submodule10and the principal surface81b.

The resin member87is arranged on the principal surface82aof the module board82and covers part of the circuit components that make up the submodule20and the principal surface82a. The resin member88is arranged on the principal surface82bof the module board82and covers part of the circuit components that make up the submodule20and the principal surface82b.

The resin members85to88has the capability of ensuring reliability, such as mechanical strength, moisture resistance, and the like, of the circuit components arranged on the module boards81and82. Note that the resin members85to88are not essential constituent elements of the radio frequency module according to the present disclosure.

As illustrated inFIG.3, in the submodule10according to the present working example, the duplexer13and the power amplifier14T are arranged on the principal surface81aof the module board81. On the other hand, the switches11and12and the low-noise amplifier14R are arranged on the principal surface81bof the module board81.

Further, as illustrated inFIG.3, in the submodule20according to the present working example, the duplexer23and the power amplifier24T are arranged on the principal surface82aof the module board82. On the other hand, the switches21and22and the low-noise amplifier24R are arranged on the principal surface82bof the module board82.

Note that although not illustrated inFIG.3, wiring lines that connect respective circuit components of the submodule10are formed in the inside of the module board81or on the principal surfaces81aand81b. Further, the foregoing wiring line may alternatively be a bonding wire whose two end portions are each joined to one of the principal surface81a, the principal surface81b, and the circuit component included in the submodule10, or may alternatively be a terminal, an electrode, or a wiring line formed on a surface of a circuit component included in the submodule10. Further, wiring lines that connect respective circuit components of the submodule20are each formed in the inside of the module board82, on the principal surface82a, or on the principal surface82b. Further, the foregoing wiring line may alternatively be a bonding wire whose two end portions are each joined to one of the principal surface82a, the principal surface82b, and the circuit component included in the submodule20, or may alternatively be a terminal, an electrode, or a wiring line formed on a surface of a circuit component included in the submodule20.

Further, in the radio frequency module1A according to the present working example, the switch12is one example of the first component, and the switch21is one example of the second component.

Here, in the radio frequency module1A according to the present working example, the connection board30is directly connected to the module board81and the module board82and electrically connects the switch12(first component) and the switch21(second component). Further, the connection board30electrically connects the switch11and the switch22.

According to the foregoing configuration, the first component and the second component are electrically connected to each other by the connection board30that is directly connected to the module board81and the module board82. Therefore, the wiring line connecting the first component and the second component can be shortened compared with the case where the first component and the second component are electrically connected to each other via a circuit component other than the connection board30and a board (for example, the mounting board91). Accordingly, the transmission loss of a radio frequency signal being transmitted between the submodule10and the submodule20can be reduced.

Further, in the submodule10, a plurality of the connection terminals150is arranged on the principal surface81bside, and in the submodule20, a plurality of the connection terminals150is arranged on the principal surface82bside. The submodule10and the submodule20send and receive electrical signals to and from each other via the mounting board91arranged on the z-axis negative direction side of the radio frequency module1A and a plurality of the connection terminals150. Further, some of the plurality of the connection terminals150are set at a ground potential of the mounting board91. On the principal surfaces81band82bthat face the mounting board91, the power amplifiers14T and24T whose profile heights are difficult to reduce are not arranged. However, the low-noise amplifiers14R and24R and the switches11,12,21, and22whose profile heights are easy to be reduced are arranged thereon. Thus, it becomes possible to reduce the profile height of the radio frequency module1A as a whole. Further, a plurality of the connection terminals150that are employed as ground electrodes are arranged around the low-noise amplifiers14R and24R that have greatly impact on the receiver sensitivity of the radio frequency module1A, and thus the degradation of the receiver sensitivity can be suppressed.

Note that as illustrated inFIG.4, the connection terminals150may be column-like electrodes that penetrate through the resin members86and88in the z-axis direction, or may be bump electrodes formed on the principal surfaces81band82b. In the case where the connection terminal150is a bump electrode, there is no need to have the resin members86and88.

Note that as illustrated inFIG.4, the metal shield layer98may be formed on each of the two principal surfaces of the connection board30, which face each other.

According to this, the metal shield layers98electromagnetically shield the wiring lines31and32from the outside of the connection board30. Thus, external noise can be reduced, and it becomes possible to improve the quality of radio frequency signals being transmitted by the wiring lines31and32.

Further, the connection board30and the module boards81and82may be composed of the same material.

According to this, the connection board30and the module boards81and82can be formed together, and this simplifies fabrication steps.

Further, the submodule10and the submodule20may be additionally electrically connected to each other via the mounting board91.

According to this, at the time of connecting a circuit component of the submodule10to a circuit component of the submodule20, it becomes possible to choose either the connection board30or the mounting board91for the connection depending on the arranged positions of the circuit components. This improves the flexibility in the arrangement of a wiring line connecting two circuit components and makes it possible to reduce the losses in the wiring line.

Further, in the radio frequency module1A according to the present working example, the duplexer13is one example of a fourth component and arranged on the principal surface81a. That is to say, the submodule10is a double-sided surface-mount type module in which the switch12(first component) is arranged on the principal surface81band the duplexer13(fourth component) is arranged on the principal surface81a.

According to this, the first component and the fourth component are arranged in such a manner as to be divided into two surfaces of the module board81, and this makes it possible to increase the packing density and reduce the size of the submodule10.

Further, as illustrated inFIG.3, the radio frequency module1A according to the present working example further includes the circuit components41to48. The circuit components41to48are examples of third components that are arranged on the mounting board91but not on the module board81or82.

Here, as illustrated inFIG.3andFIG.4, in the plan view of the mounting board91, of the circuit components41to48, the circuit components41and42overlap at least partially with the connection board30.

According to this, the region where the connection board30is arranged can be effectively shared as a mounting space of the circuit components41and42, and thus it becomes possible to reduce the size of the radio frequency module1A. Further, compared with the case where the circuit components41and42are built into the submodule10or20, the isolation between the circuit components41and42and other circuit components built into the submodule10or20is improved.

Note that in the submodule10according to the present working example, the duplexer13and the power amplifier14T are arranged on the principal surface81a, and the switches11and12and the low-noise amplifier14R are arranged on the principal surface81b. However, the present disclosure is not limited thereto. For example, the switches11and12may be arranged on the principal surface81a, and the duplexer13may be arranged on the principal surface81b.

Further, in the submodule20according to the present working example, the duplexer23and the power amplifier24T are arranged on the principal surface82a, and the switches21and22and the low-noise amplifier24R are arranged on the principal surface82b. However, the present disclosure is not limited thereto. For example, the switches21and22may be arranged on the principal surface82a, and the duplexer23may be arranged on the principal surface82b.

Further, the first component of the submodule10and the second component of the submodule20, which are connected to each other via the connection board30, are not limited to the switch12and the switch21, respectively. The first component and the second component may alternatively be the switch11and the switch22, respectively. Moreover, the first component and the second component are not necessarily switches so long as the first component and the second component are circuit components to be connected to each other via the connection board30.

Further, in the submodule10according to the present working example, the power amplifier14T is arranged on the principal surface81a, and the low-noise amplifier14R is arranged on the principal surface81b.

According to this, the power amplifier14T that amplifies a transmit signal and the low-noise amplifier14R that amplifies a receive signal are arranged in such a manner as to be divided into two surfaces of the module board81, and this improves the isolation between transmitting and receiving in the submodule10.

Further, in the submodule20according to the present working example, the power amplifier24T is arranged on the principal surface82a, and the low-noise amplifier24R is arranged on the principal surface82b.

According to this, the power amplifier24T that amplifies a transmit signal and the low-noise amplifier24R that amplifies a receive signal are arranged in such a manner as to be divided into two surfaces of the module board82, and this improves the isolation between transmitting and receiving in the submodule20.

It is desirable that each of the module boards81and82has a multilayer structure in which a plurality of dielectric layers are stacked on top of each other and that a ground electrode pattern is formed on at least one of the plurality of dielectric layers. This improves the capability of electromagnetic shielding of the module boards81and82.

Note that instead of the connection board30, the radio frequency module1according to the present embodiment may include a coaxial wiring line that connects the submodule10and submodule20. That is to say, the radio frequency module1may include the mounting board91, the submodule10arranged on the mounting board91, the submodule20arranged on the mounting board91, and the coaxial wiring line that connects the submodule10and the submodule20. The foregoing coaxial wiring line may be arranged in such a manner as to be separated from the mounting board91, may be directly connected to the module boards81and82, and may electrically connect the first component and the second component.

Note that the coaxial wiring line is one type of covered electric cable for use in electrical communications and is made up of an inner conductor (core line), an outer shield conductor formed in such a manner as to coaxially cover the inner conductor (core line), and a dielectric body formed between the inner conductor (core line) and the outer shield conductor.

According to this, the first component and the second component are electrically connected to each other by the coaxial wiring line that is directly connected to the module board81and the module board82. Therefore, the wiring line connecting the first component and the second component can be shortened compared with the case where the first component and the second component are electrically connected to each other via the mounting board91. Accordingly, the transmission loss of a radio frequency signal being transmitted between the submodule10and the submodule20can be reduced.

4. Circuit Element Layout Configuration of Radio Frequency Module1B According to Modified Example

FIG.5is a sectional view of schematic configuration of a radio frequency module1B according to a modified example. The radio frequency module1B according to the present modified example is the one in which the layout configuration of the respective circuit elements that make up the radio frequency module1according to the embodiment is specified.

The radio frequency module1B according to the present modified example is different from the radio frequency module1A according to the working example in that the submodules10and20are respectively mounted on different mounting boards91A and91B and that the connection board30is a flexible board. Hereinafter, the radio frequency module1B according to the present modified example is described with the emphasis on points different from the radio frequency module1A according to the working example, and the descriptions for the same points as the radio frequency module1A according to the working example are omitted.

As illustrated inFIG.5, in addition to the circuit configuration illustrated inFIG.1, the radio frequency module1B according to the present modified example further includes the mounting boards91A and91B, the module boards81and82, the connection board30, the connection terminals150, the resin members85to88, and the metal shield layers96and97.

The mounting board91A has a principal surface91cand a principal surface91d, which face each other, and is a board on which the submodule10is mounted. The mounting board91B has a principal surface91eand a principal surface91f, which face each other, and is a board on which the submodule20is mounted. As the mounting boards91A and91B, for example, a LTCC board, a HTCC board, a board with built-in components, a board including an RDL, a printed board, or the like, each of which has a multilayer structure including a plurality of dielectric layers, may be used.

The submodule10is arranged on the principal surface91cof the mounting board91A. The submodule20is arranged on the principal surface91eof the mounting board91B.

The connection board30according to the present modified example is a board that connects the submodule10and the submodule20. The connection board30has two principal surfaces that face each other. As the connection board30, a flexible board such as, for example, a resin multilayer board that uses liquid crystal polymer or a similar board may be used. The resin multilayer board that uses liquid crystal polymer is a board that can be bent flexibly and can retain a bent state. In the inside of the connection board30, the wiring line32(first wiring line) that connects the first component of the submodule10and the second component of the submodule20is formed.

Note that the module boards81and82of the present modified example may be composed of a material different from that of the connection board30or may be composed of the same material as that of the connection board30.

In the radio frequency module1B according to the present modified example, the connection board30is directly connected to the module board81and the module board82and electrically connects the switch12(first component) and the switch21(second component).

According to the foregoing configuration, the first component and the second component are electrically connected to each other by the connection board30that is directly connected to the module board81and the module board82. Therefore, the wiring line connecting the first component and the second component can be shortened compared with the case where the first component and the second component are electrically connected to each other via the mounting boards91A and91B. Accordingly, the transmission loss of a radio frequency signal being transmitted between the submodule10and the submodule20can be reduced.

Further, in the present modified example, because the connection board30is a flexible board, the submodule10and the submodule20can be arranged, for example, in such a manner as to face each other in the vertical direction of the module boards81and82. Further, the submodules10and20can be arranged in a region sandwiched between the mounting boards91A and91B, which are arranged in such a manner as to face each other. That is to say, because the flexibility in the layout of the submodules10and20is improved, it becomes possible to increase the packing density and reduce the size of the radio frequency module1B.

5. Advantageous Effects and the Like

As described above, the radio frequency module1A according to the present working example includes the submodules10and20and the connection board30that connects the submodule10and the submodule20. The submodule10includes the module board81and the first component arranged on the module board81, the submodule20includes the module board82and the second component arranged on the module board82, and the connection board30is directly connected to the module boards81and82and electrically connects the first component and the second component.

According to this, the first component and the second component are electrically connected to each other by the connection board30that is directly connected to the module boards81and82. Therefore, the wiring line connecting the first component and the second component can be shortened compared with the case where the first component and the second component are electrically connected to each other via a circuit component other than the connection board30and a board (for example, the mounting board91). Accordingly, the transmission loss of a radio frequency signal being transmitted between the submodule10and the submodule20can be reduced.

Further, in the radio frequency module1A, the metal shield layer98may be formed on each of the two principal surfaces of the connection board30, which face each other, and the wiring line32that connects the first component and the second component may be formed in the inside of the connection board30.

According to this, the metal shield layers98electromagnetically shield the wiring line32from the outside of the connection board30. Thus, external noise can be reduced, and it becomes possible to improve the quality of a radio frequency signal being transmitted by the wiring line32.

Further, in the radio frequency module1A, the connection board30and the module boards81and82may be composed of the same material.

According to this, the connection board30and the module boards81and82can be formed together, and this simplifies fabrication steps.

Further, the radio frequency module1B according to the present modified example may be a flexible board.

According to this, the flexibility in the layout of the submodules10and20is improved, and this makes it possible to increase the packing density and reduce the size of the radio frequency module1B.

Further, the radio frequency module1A may further include the mounting board91on which the submodules10and20are arranged.

Further, the radio frequency module1A may further include the third component that is arranged on the mounting board91but not on the module board81or82.

Further, in the radio frequency module1A, in the plan view of the mounting board91, the third component may overlap at least partially with the connection board30.

According to this, the region where the connection board30is arranged can be effectively shared as a mounting space of the third component, and thus it becomes possible to reduce the size of the radio frequency module1A.

Further, in the radio frequency module1A, the submodule10and the submodule20may be electrically connected to each other via the mounting board91.

According to this, at the time of connecting the submodules10and20, it becomes possible to choose either the connection board30or the mounting board91for the connection. This improves the flexibility in the layout of wiring lines and makes it possible to reduce the losses in the wiring lines.

Further, the radio frequency module1A may further include the fourth component, the first component may be arranged on the principal surface81b, and the fourth component may be arranged on the principal surface81a.

According to this, the first component and the fourth component are arranged in such a manner as to be divided into two surfaces of the module board81, and this makes it possible to increase the packing density and reduce the size of the submodule10.

Further, in the radio frequency module1A, the submodule10may further include the switch11, the first component may be the switch12, the fourth component may be the duplexer13, the submodule20may further include the switch22and the duplexer23, the second component may be the switch21, the switch11may switch between connecting and disconnecting the antenna connection terminal110to and from the switch12and may switch between connecting and disconnecting the antenna connection terminal110to and from the switch22, the switch21may switch between connecting and disconnecting the antenna connection terminal120to and from the switch12and may switch between connecting and disconnecting the antenna connection terminal120to and from the switch22, the switch12may switch between connecting the duplexer13to the switch11and connecting the duplexer13to the switch21, the switch22may switch between connecting the duplexer23to the switch21and connecting the duplexer23to the switch11, and the switch12and the switch21may be connected to each other via the connection board30.

Further, in the radio frequency module1A, the submodule10may further include the connection terminal150that is arranged on the principal surface81band connects the module board81and the mounting board91, the first component may be arranged on the principal surface81b, and the fourth component may be arranged on the principal surface81a.

Further, the radio frequency module1according to the present embodiment may include the mounting board91, the submodule10arranged on the mounting board91, the submodule20arranged on the mounting board91, and the coaxial wiring line that connects the submodule10and the submodule20. The submodule10may include the module board81and the first component arranged on the module board81, the submodule20may include the module board82and the second component arranged on the module board82, and the coaxial wiring line may be directly connected to the module boards81and82and electrically connect the first component and the second component.

According to this, the first component and the second component are electrically connected to each other by the coaxial wiring line that is directly connected to the module board81and the module board82. Therefore, the wiring line connecting the first component and the second component can be shortened compared with the case where the first component and the second component are electrically connected to each other via the mounting board91. Accordingly, the transmission loss of a radio frequency signal being transmitted between the submodule10and the submodule20can be reduced.

Further, the communication device4includes the RFICs3A and3B that perform processing on radio frequency signals being transmitted and received by the antennas2A and2B, and the radio frequency module1that transmits radio frequency signals between the antennas2A and2B and the RFICs3A and3B.

According to this, it becomes possible to provide the communication device4that can reduce the transmission loss of the submodules10and20arranged on the mounting board91.

Further, in the communication device4, the antenna2A may be connected to the antenna connection terminal110, and the antenna2B may be connected to the antenna connection terminal120.

Other Embodiments and the Like

The radio frequency modules and the communication devices according to embodiments of the present disclosure have been described using the embodiment, the working example, and the modified example. However, the radio frequency module and the communication device according to the present disclosure are not limited to the foregoing embodiment, working example, and modified example. Other embodiments realized by combining optional constituent elements of the foregoing embodiment, working example, and modified example, modified examples obtained by applying various modifications conceivable to those skilled in the art to the foregoing embodiment, working example, and modified example without departing the scope of the present disclosure, and various devices incorporating the foregoing radio frequency module and communication device may also be included in the present disclosure.

For example, in the radio frequency module and the communication device according to the foregoing embodiment, working example, and modified example, another circuit element, a wiring line, or the like may be inserted in a path connecting each circuit element and a signal path disclosed in the drawings.

The present disclosure can be widely used in communication devices such as mobile phones and the like as a radio frequency module to be installed in a multiband front-end unit.

1,1A,1B Radio frequency module

3A,3B RF signal processing circuit (RFIC)

Selection Terminal

13R,23R Receive filter

14T,24T Power amplifier

Principal Surface

91,91A,91B Mounting board

110,120Antenna connection terminal

111,121Transmit input terminal

112,122Receive output terminal