Patent Publication Number: US-2023155612-A1

Title: Radio frequency module and communication device

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This is a continuation of International Application No. PCT/JP2021/024660 filed on Jun. 30, 2021 which claims priority from Japanese Patent Application No. 2020-127779 filed on Jul. 28, 2020. The contents of these applications are incorporated herein by reference in their entireties. 
    
    
     BACKGROUND ART 
     Technical Field 
     The present disclosure relates to a radio frequency (RF) module and a communication device. 
     In recent mobile phones, in addition to making one terminal capable of supporting multiple modes and multiple communication bands corresponding to multiple communication systems, it is also suitable for one terminal to be able to perform simultaneous communication with multiple communication systems and/or in multiple communication bands. For example, Patent Document 1 discloses a diversity module for transmitting an uplink signal from a diversity antenna. 
     Patent Document 1: Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2017-527155 
     BRIEF SUMMARY 
     However, in the above-described background art, when simultaneous communication is performed in multiple communication bands, a transmission signal and a reception signal may interfere with each other, causing a decrease in reception sensitivity. 
     Therefore, the present disclosure provides a radio frequency module and a communication device capable of suppressing the interference between a transmission signal and a reception signal in the case where simultaneous communication is performed in multiple communication bands. 
     A radio frequency module according to an aspect of the present disclosure includes: a module substrate having a first main surface and a second main surface facing each other and having an outline that is rectangular in plan view; a plurality of external connection terminals arranged on the second main surface and including a radio frequency input terminal for receiving an amplified transmission signal from outside, a first radio frequency output terminal and a second radio frequency output terminal for supplying a reception signal to outside, and an antenna connection terminal; a first filter arranged on the first main surface, connected between the radio frequency input terminal/the first radio frequency output terminal and the antenna connection terminal, and having a passband including a first communication band for time division duplex (TDD); and a second filter arranged on the first main surface, connected between the second radio frequency output terminal and the antenna connection terminal, and having a passband including at least part of a second communication band allowed for simultaneous communication with the first communication band; wherein the radio frequency input terminal is arranged in a first region on the second main surface, extending along a first side among four sides forming the rectangular outline of the module substrate, and the second radio frequency output terminal is arranged in a second region on the second main surface, extending along a second side facing the first side, among the four sides forming the rectangular outline of the module substrate. 
     According to the present disclosure, the interference between a transmission signal and a reception signal can be suppressed in the case where simultaneous communication is performed in multiple communication bands. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a circuit diagram of a radio frequency (RF) module and a communication device according to an embodiment. 
         FIG.  2 A  is a plan view of the RF module according to the embodiment. 
         FIG.  2 B  is a plan view of the RF module according to the embodiment. 
         FIG.  3    is an enlarged plan view of the RF module according to the embodiment. 
         FIG.  4    is an enlarged plan view of the RF module according to the embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, an embodiment of the present disclosure will be described in detail using the drawings. Note that the embodiment described below indicates comprehensive or specific examples. Numerical values, shapes, materials, elements, the arrangement and connection forms of elements, and the like discussed in the following embodiment are examples and are not intended to limit the present disclosure. 
     Note that each drawing is a schematic diagram in which an emphasis, omission, or ratio adjustment is performed as appropriate to indicate the present disclosure. Each drawing is not necessarily strictly illustrated, and may differ from the actual shapes, positional relationships, and ratios. In each drawing, substantially the same configurations are denoted by the same reference sign, and duplicate descriptions may be omitted or simplified. 
     In each drawing hereinafter, the x-axis and the y-axis are axes perpendicular to each other on a plane parallel to a main surface of a module substrate. The z-axis is an axis perpendicular to the main surface of the module substrate, and the positive direction thereof indicates the upward direction and the negative direction indicates the downward direction. 
     Moreover, in the circuit configuration of the present disclosure, “connected” includes not only cases of being directly connected by a connection terminal and/or a wiring conductor, but also cases of being electrically connected with another circuit element interposed therebetween. Also, “connected between A and B” means being connected to both A and B between A and B. 
     Furthermore, in the module configuration of the present disclosure, “in plan view” means viewing an object by orthographic projection from the z-axis positive side to the xy plane. “A component is arranged on a main surface of a substrate” includes, in addition to the component being arranged on the main surface while being in contact with the main surface of the substrate, the component being arranged above the main surface without necessarily being in contact with the main surface and the component being arranged by being partially embedded in the substrate from the main surface side. “A is arranged between B and C” means that at least one of line segments connecting any point within B and any point within C passes through A. In addition, terms indicating relationships between elements, such as “parallel” and “perpendicular”, and terms indicating the shapes of elements, such as “rectangular”, do not represent only the strict meanings, but also include substantially equivalent ranges, such as including an error of about several percent. 
     Embodiment 
     [1.1 Circuit Configuration of Radio Frequency Module  1  and Communication Device  5 ] 
     The circuit configuration of a radio frequency (RF) module  1  and a communication device  5  according to the present embodiment will be described with reference to  FIG.  1   .  FIG.  1    is a circuit configuration diagram of the RF module  1  and the communication device  5  according to a first embodiment. 
     [1.1.1 Circuit Configuration of Communication Device  5 ] 
     Firstly, the circuit configuration of the communication device  5  will be described. As illustrated in  FIG.  1   , the communication device  5  according to the present embodiment includes the RF module  1 , an antenna  2 , an RFIC  3 , and a BBIC  4 . 
     The RF module  1  transmits an RF signal between the antenna  2  and the RFIC  3 . The RF module  1  can be used as a diversity module capable of transmitting RF signals for TDD in addition to receiving RF signals for TDD and frequency division duplex (FDD). The detailed circuit configuration of the RF module  1  will be described later. 
     The antenna  2  is connected to an antenna connection terminal  100  of the RF module  1 . The antenna  2  transmits an RF signal output from the RF module  1 , and also receives an RF signal from the outside and outputs it to the RF module  1 . 
     The RFIC  3  is an example of a signal processing circuit that processes an RF signal. Specifically, the RFIC  3  applies signal processing, such as downconverting, to an RF reception signal input through a reception path of the RF module  1 , and outputs a reception signal generated by the signal processing to the BBIC  4 . In addition, the RFIC  3  applies signal processing, such as upconverting, to a transmission signal input from the BBIC  4 , and outputs an RF transmission signal generated by the signal processing to a transmission path of the RF module  1  by way of an amplifier circuit or the like. Moreover, the RFIC  3  has a controller that controls switches and amplifiers included in the RF module  1 . Note that some or all of the functions as the controller of the RFIC  3  may be mounted outside the RFIC  3 , such as on the BBIC  4  or the RF module  1 . 
     The BBIC  4  is a baseband signal processing circuit that applies signal processing using an intermediate frequency band lower than RF signals transmitted by the RF module  1 . As signals processed by the BBIC  4 , for example, an image signal for displaying an image and/or an audio signal for conversation using a loudspeaker is used. 
     Note that the antenna  2  and the BBIC  4  are optional elements of the communication device  5  according to the present embodiment. 
     [1.1.2 Circuit Configuration of RF Module  1 ] 
     Next, the circuit configuration of the RF module  1  will be described. As illustrated in  FIG.  1   , the RF module  1  includes low noise amplifiers  21  to  24 , switches  51  and  52 , filters  61  to  64 , matching circuits (MN)  71  to  73 , the antenna connection terminal  100 , an RF input terminal  110 , and RF output terminals  121  to  124 . 
     The antenna connection terminal  100  is connected to the antenna  2 . 
     The RF input terminal  110  is a terminal for receiving an amplified RF transmission signal from the outside of the RF module  1 . Specifically, the RF input terminal  110  is a terminal for receiving a transmission signal that is in communication band D for TDD and that has been amplified by an external power amplifier circuit. 
     Here, communication bands mean frequency bands defined in advance by standardization organizations for communication systems (such as 3GPP (3rd Generation Partnership Project) and IEEE (Institute of Electrical and Electronics Engineers)). The communication systems mean communication systems configured using radio access technology (RAT). As the communication systems, for example, 5GNR (5th Generation New Radio) systems, LTE (Long Term Evolution) systems, and WLAN (Wireless Local Area Network) systems can be used, but these are not the only possible types of communication systems. 
     The RF output terminals  121  to  124  are terminals for providing an RF reception signal to the outside of the RF module  1 . Specifically, the RF output terminal  121  is an example of a second RF output terminal, and is a terminal for supplying a reception signal in communication band A to the RFIC  3 . The RF output terminal  122  is an example of the second RF output terminal, and is a terminal for supplying a reception signal in communication band B to the RFIC  3 . The RF output terminal  123  is an example of a third RF output terminal, and is a terminal for supplying a reception signal in communication band C to the RFIC  3 . The RF output terminal  124  is an example of a first RF output terminal, and is a terminal for supplying a reception signal in communication band D to the RFIC  3 . 
     Each of communication bands A and B is an example of a second communication band, and is allowed for simultaneous communication with communication band D. As a combination of communication bands A and B, the combination of Band  1 l and Band  3  for LTE can be used, but this is not the only possible combination. For example, as a combination of communication bands A and B, any two of Band  1  and Band  3  for LTE and n75 and n76 for 5GNR may be used. Alternatively, for example, as a combination of communication bands A and B, Band  25  and Band  66  for LTE may be used. Alternatively, for example, frequency bands for WLAN may be used as communication bands A and/or B. Alternatively, for example, a millimeter wave band of 7 GHz or more may be used as communication bands A and/or B. 
     Communication band C is an example of a third communication band, and does not allow for simultaneous communication with communication band D. As communication band C, Band  40  for LTE may be used, but this is not the only possible type of communication band. For example, Band  7  for LTE may be used as communication band C. Alternatively, for example, a frequency band for 5GNR or WLAN may be used as communication band C. Alternatively, for example, a millimeter wave band of 7 GHz or more may be used as communication band C. 
     Communication band D is an example of a first communication band, and is a communication band for TDD. As communication band D, Band  41  for LTE and/or n41 for 5GNR may be used, but this is not the only possible type of communication band. For example, a frequency band for WLAN may be used as communication band D. Alternatively, for example, a millimeter wave band of 7 GHz or more may be used as communication band D. 
     Note that multiple communication bands allowed for simultaneous communication means that at least one of simultaneous transmission, simultaneous reception, and simultaneous transmission/reception is allowed in multiple communication bands. At this time, each of multiple communication bands being used independently is not excluded. Combinations of communication bands allowed for simultaneous communication are defined in advance by, for example, standardization organizations for communication systems. 
     In addition, multiple communication bands not allowed for simultaneous communication means that none of simultaneous transmission, simultaneous reception, and simultaneous transmission/reception is allowed in multiple communication bands. Combinations of communication bands not allowed for simultaneous communication are combinations of communication bands excluding combinations of communication bands allowed for simultaneous communication. 
     The low noise amplifier  21  is connected between the filter  61  and the RF output terminal  121 . The low noise amplifier  21  can amplify a reception signal in communication band A that has been input from the antenna connection terminal  100  by way of the switch  51 , the matching circuit  71 , and the filter  61 . The reception signal in communication band A that has been amplified by the low noise amplifier  21  is output to the RF output terminal  121 . 
     The low noise amplifier  22  is connected between the filter  62  and the RF output terminal  122 . The low noise amplifier  22  can amplify a reception signal in communication band B that has been input from the antenna connection terminal  100  by way of the switch  51 , the matching circuit  71 , and the filter  62 . The reception signal in communication band B that has been amplified by the low noise amplifier  22  is output to the RF output terminal  122 . 
     The low noise amplifier  23  is connected between the filter  63  and the RF output terminal  123 . The low noise amplifier  23  can amplify a reception signal in communication band C that has been input from the antenna connection terminal  100  by way of the switch  51 , the matching circuit  72 , and the filter  63 . The reception signal in communication band C that has been amplified by the low noise amplifier  23  is output to the RF output terminal  123 . 
     The low noise amplifier  24  is connected between the filter  64  and the RF output terminal  124 . The low noise amplifier  24  can amplify a reception signal in communication band D that has been input from the antenna connection terminal  100  by way of the switch  51 , the matching circuit  73 , the filter  64 , and the switch  52 . The reception signal in communication band D that has been amplified by the low noise amplifier  24  is output to the RF output terminal  124 . 
     The filter  61  (A-Rx) is an example of a second filter, and has a passband including the downlink operation band of communication band A. Accordingly, the filter  61  can pass a reception signal in communication band A and attenuate a transmission signal in communication band A, and a transmission signal and a reception signal in other communication bands not overlapping with communication band A. 
     The filter  61  has an input terminal  611  and an output terminal  612 . The input terminal  611  is connected to the antenna connection terminal  100  with the matching circuit  71  and the switch  51  interposed therebetween. The output terminal  612  is connected to the input of the low noise amplifier  21 . 
     The filter  62  (B-Rx) is an example of the second filter, and has a passband including the downlink operation band of communication band B. Accordingly, the filter  62  can pass a reception signal in communication band B and attenuate a transmission signal in communication band B, and a transmission signal and a reception signal in other communication bands not overlapping with communication band B. 
     The filter  62  has an input terminal  621  and an output terminal  622 . The input terminal  621  is connected to the antenna connection terminal  100  with the matching circuit  71  and the switch  51  interposed therebetween. The output terminal  622  is connected to the input of the low noise amplifier  22 . 
     The filters  61  and  62  form a multiplexer. That is, the filters  61  and  62  are bundled into one and connected to one terminal of the switch  51 . 
     The filter  63  (C-Rx) is an example of a third filter, and has a passband including the downlink operation band of communication band C. Accordingly, the filter  63  can pass a reception signal in communication band C and attenuate a transmission signal in communication band C, and a transmission signal and a reception signal in other communication bands not overlapping with communication band C. 
     The filter  63  has an input terminal  631  and an output terminal  632 . The input terminal  631  is connected to the antenna connection terminal  100  with the matching circuit  72  and the switch  51  interposed therebetween. The output terminal  632  is connected to the input of the low noise amplifier  23 . 
     The filter  64  (D-TRx) is an example of a first filter, and has a passband including communication band D. Accordingly, the filter  64  can pass a transmission signal and a reception signal in communication band D and attenuate a transmission signal and a reception signal in other communication bands not overlapping with communication band D. 
     The filter  64  has two input/output terminals  641  and  642 . The input/output terminal  641  is connected to the antenna connection terminal  100  with the matching circuit  73  and the switch  51  interposed therebetween. The input/output terminal  642  is connected to the input of the low noise amplifier  24  or the RF input terminal  110  with the switch  52  interposed therebetween. 
     The switch  51  is connected between the antenna connection terminal  100  and the filters  61  to  64 . Specifically, the switch  51  has terminals  511  to  514 . The terminal  511  is connected to the antenna connection terminal  100 . The terminal  512  is connected to the filters  61  and  62  with the matching circuit  71  interposed therebetween. The terminal  513  is connected to the filter  63  with the matching circuit  72  interposed therebetween. The terminal  514  is connected to the filter  64  with the matching circuit  73  interposed therebetween. 
     In this connection configuration, the switch  51  can connect the terminal  511  to at least one of the terminals  512  to  514  based on, for example, a control signal from the RFIC  3 . That is, the switch  51  can switch connection and non-connection between the antenna  2  and each of the filters  61  to  64 . The switch  51  is formed of, for example, a multi-connection switch circuit, and may be called an antenna switch. 
     The switch  52  is connected between the filter  64  and the RF input terminal  110 /the low noise amplifier  24 . Specifically, the switch  52  has terminals  521  to  523 . The terminal  521  is connected to the input/output terminal  642  of the filter  64 . The terminal  522  is connected to the input of the low noise amplifier  24 , and the terminal  523  is connected to the RF input terminal  110 . 
     In this connection configuration, the switch  52  can connect the terminal  521  to either the terminal  522  or  523  based on, for example, a control signal from the RFIC  3 . That is, the switch  52  can switch between connection of the filter  64  and the low noise amplifier  24  and connection of the filter  64  and the RF input terminal  110 . The switch  52  is formed of, for example, an SPDT (Single Pole Double Throw) type switch circuit, and may be called a TDD switch. 
     The matching circuit  71  is formed of, for example, an inductor and/or a capacitor, and can perform impedance matching between the antenna  2  and the filters  61  and  62 . The matching circuit  71  is connected between the switch  51  and the filters  61  and  62 . Specifically, the matching circuit  71  is connected to both the input terminal  611  of the filter  61  and the input terminal  621  of the filter  62 , and is connected to the antenna connection terminal  100  with the switch  51  interposed therebetween. 
     The matching circuit  72  is formed of, for example, an inductor and/or a capacitor, and can perform impedance matching between the antenna  2  and the filter  63 . The matching circuit  72  is connected between the switch  51  and the filter  63 . Specifically, the matching circuit  72  is connected to the input terminal  631  of the filter  63 , and is connected to the antenna connection terminal  100  with the switch  51  interposed therebetween. 
     The matching circuit  73  is formed of, for example, an inductor and/or a capacitor, and can perform impedance matching between the antenna  2  and the filter  64 . The matching circuit  73  is connected between the switch  51  and the filter  64 . Specifically, the matching circuit  73  is connected to the input/output terminal  641  of the filter  64 , and is connected to the antenna connection terminal  100  with the switch  51  interposed therebetween. 
     Note that some of the circuit elements illustrated in  FIG.  1    need not be included in the RF module  1 . For example, the RF module  1  only needs to include at least the filter  61  or  62 , and the filter  64 , and need not include other circuit elements. 
     [1.2 Arrangement of Components of RF Module  1 ] 
     Next, the arrangement of components of the RF module  1  formed as above will be specifically described with reference to  FIGS.  2 A to  4   . 
       FIGS.  2 A and  2 B  are plan views of the RF module  1  according to the embodiment. Specifically,  FIG.  2 A  illustrates a view of a main surface  91   a  of a module substrate  91  from the z-axis positive side.  FIG.  2 B  illustrates a view of a main surface  91   b  of the module substrate  91  from the z-axis positive side.  FIG.  3    is an enlarged plan view of the RF module  1  according to the embodiment. Specifically,  FIG.  3    is an enlarged view of a region iii in  FIG.  2 A .  FIG.  4    is an enlarged plan view of the RF module  1  according to the embodiment. The cross section of the RF module  1  in  FIG.  4    is a cross section taken along line iv-iv of  FIG.  3   . 
     As illustrated in  FIGS.  2 A and  2 B , the RF module  1  further includes, in addition to circuit components forming the circuit illustrated in  FIG.  1   , the module substrate  91  and external connection terminals  150 . 
     The module substrate  91  has the main surface  91   a  and the main surface  91   b  facing each other. Examples of the module substrate  91  include a low-temperature co-fired ceramics substrate (LTCC), a high-temperature co-fired ceramics substrate (HTCC), a component built-in substrate, a substrate with a redistribution layer (RDL), and a printed circuit board, having a multilayer structure of multiple dielectric layers, but these are not the only possible types of substrate. 
     The main surface  91   a  is an example of a first main surface, and may be called an upper surface or a surface. As illustrated in  FIG.  2 A , the low noise amplifiers  21  to  24 , the switches  51  and  52 , the filters  61  to  64 , and the matching circuits  71  to  73  are arranged on the main surface  91   a.    
     The low noise amplifiers  21  to  24  and the switches  51  and  52  are built into a semiconductor integrated circuit (IC)  20  having an outline that is rectangular in plan view. The semiconductor IC  20  is an electronic circuit formed on the surface of and inside a semiconductor chip (may also be called a die), and the semiconductor IC  20  may also be called a semiconductor component. The semiconductor IC  20  is formed of, for example, CMOS (Complementary Metal Oxide Semiconductor), and specifically may be formed by an SOI (Silicon on Insulator) process. Accordingly, the semiconductor IC  20  can be manufactured at low cost. Note that the semiconductor IC  20  may be formed of at least one of GaAs, SiGe, and GaN. Accordingly, the high-quality semiconductor IC  20  can be realized. 
     The semiconductor IC  20  has terminals  201  to  206  in the vicinity of outer edges of the semiconductor IC  20  in plan view. As the terminals  201  to  206 , for example, electrode pads, bump electrodes, or lead electrodes can be used, but these are not the only possible types of electrodes that can be used as the terminals  201  to  206 . 
     The terminal  201  is an example of a first terminal, is connected to the antenna connection terminal  100 , and is connected to the terminal  511  of the switch  51  in the semiconductor IC  20 . The terminal  202  is connected by a wire  84  to the matching circuit  73  and the input/output terminal  641  of the filter  64 . In addition, the terminal  202  is connected to the terminal  514  of the switch  51  in the semiconductor IC  20 . The terminal  203  is connected by a wire  83  to the matching circuit  72  and the input terminal  631  of the filter  63 . Moreover, the terminal  203  is connected to the terminal  513  of the switch  51  in the semiconductor IC  20 . The terminal  204  is connected by wires  81  and  82  to the matching circuit  71 , the input terminal  621  of the filter  62 , and the input terminal  611  of the filter  61 . In addition, the terminal  204  is connected to the terminal  512  of the switch  51  in the semiconductor IC  20 . 
     The terminals  201  to  204  are arranged in a region  212  (hatched region) of the semiconductor IC  20 . The region  212  is an example of a third region, and is a virtual region extending along a side  211 , which is one example of a third side, among four sides forming the rectangular outline of the semiconductor IC  20 . Accordingly, the terminals  201  to  204  are arranged in the vicinity of the side  211 . 
     The terminal  205  is an example of a second terminal, is connected to the RF output terminal  122 , and is connected to the output of the low noise amplifier  22  in the semiconductor IC  20 . The terminal  206  is an example of the second terminal, is connected to the RF output terminal  121 , and is connected to the output of the low noise amplifier  21  in the semiconductor IC  20 . 
     The terminals  205  and  206  are arranged in a region  214  of the semiconductor IC  20 . The region  214  is an example of a fourth region and is a virtual region extending along a side  213 , which is an example of a fourth side, among the four sides forming the rectangular outline of the semiconductor IC  20 . The side  213  faces the side  211 . Accordingly, the terminals  205  and  206  are arranged in the vicinity of the side  213  facing the side  211 , and are arranged away from the terminals  201  to  204 . 
     The wire  81  is an example of a second wire, and connects the terminal  204  of the semiconductor IC  20  and the filter  61 . Specifically, as illustrated in  FIGS.  2 A and  3   , the wire  81  connects the terminal  204  and the matching circuit  71 , and connects the matching circuit  71  and the input terminal  611  of the filter  61 . 
     The wire  82  is an example of the second wire, and connects the terminal  204  of the semiconductor IC  20  and the filter  62 . Specifically, as illustrated in  FIGS.  2 A and  3   , the wire  82  connects the terminal  204  and the matching circuit  71 , and connects the matching circuit  71  and the input terminal  621  of the filter  62 . The wires  81  and  82  connecting the terminal  204  and the matching circuit  71  are a common wire. 
     The wire  83  is an example of a third wire, and connects the terminal  203  of the semiconductor IC  20  and the filter  63 . Specifically, as illustrated in  FIG.  2 A , the wire  83  connects the terminal  203  and the matching circuit  72 , and connects the matching circuit  72  and the input terminal  631  of the filter  63 . 
     The wire  84  is an example of a first wire, and connects the terminal  202  of the semiconductor IC  20  and the filter  64 . Specifically, as illustrated in  FIG.  2 A , the wire  84  connects the terminal  202  and the matching circuit  73 , and connects the matching circuit  73  and the input/output terminal  641  of the filter  64 . 
     Planar pattern electrodes on the main surface  91   a  can be used as the wires  81  to  84 , but these are not the only possible types of wires  81  to  84 . For example, bonding wires may be used as some or all of the wires  81  to  84 . 
     Here, the length of each of the wires  81 ,  82 , and  84  is less than the length of the wire  83 . That is, the wire between each of the filters  61 ,  62 , and  64  for communication bands A, B, and D, which are allowed for simultaneous communication, and the switch  51  is shorter than the wire between the filter  63  for communication band C, which is not allowed for simultaneous communication, and the switch  51 . 
     As illustrated in  FIG.  4   , immediately below the wires  81  and  82  and the matching circuit  71 , pattern electrodes in second and third layers among multiple wiring layers in the module substrate  91  are removed. Here, the ordinal numbers of the wiring layers are assigned in ascending order from the main surface  91   a  side to the main surface  91   b  side. The first layer is a wiring layer on the main surface  91   a.  The second to fifth layers are wiring layers in the module substrate  91 . The sixth layer is a wiring layer on the main surface  91   b.    
     Note that the wiring layers from which pattern layers are removed are not limited to the second and third layers, but may be only the second layer, the second to fourth layers, or the second to fifth layers. That is, in plan view, in a region overlapping with at least one of the wires  81  and  82  and the matching circuit  71 , no pattern electrode is arranged on the main surface  91   a  side of at least one of the wiring layers in the module substrate  91 . 
     This can reduce the parasitic capacitance generated between the wires  81  and  82  bundling the filters  61  and  62  and the pattern electrodes in the module substrate  91 . As a result, the impedance mismatching loss due to the parasitic capacitance of the filters  61  and  62  can be reduced in simultaneous communication of communication bands A and B, and the electrical characteristics of the RF module  1  can be improved. 
     Note that the total number of wiring layers in the module substrate  91  is not limited to six, and may be more or less than six. 
     The filters  61  to  64  are arranged in the vicinity of the side  211  of the semiconductor IC  20 . The filter  63  is arranged between the filters  62  and  64 . Acoustic wave filters using BAW (Bulk Acoustic Wave), LC filters, dielectric filters, and distribution constant type filters may be used as the filters  61  to  64 , and furthermore, these are not the only possible types of filters used as the filters  61  to  64 . 
     The main surface  91   b  is an example of a second main surface, and may be called a bottom surface or a back surface. As illustrated in  FIG.  2 B , the external connection terminals  150  are arranged on the main surface  91   b.    
     The external connection terminals  150  include the antenna connection terminal  100 , the RF input terminal  110 , the RF output terminals  121  to  124 , and ground terminals GND. The external connection terminals  150  are connected to input/output terminals and/or ground electrode or the like on a motherboard arranged in the z-axis negative direction of the RF module  1 . Pad electrodes can be used as the external connection terminals  150 , but this is not the only possible type of electrode used as the external connection terminals  150 . For example, post electrodes or bump electrodes protruding from the main surface  91   b  may be used as the external connection terminals  150 . 
     The RF input terminal  110 , which is one of the external connection terminals  150 , is arranged in a region  912  (hatched region) on the main surface  91   b.  The region  912  is an example of a first region, and is a virtual region extending along a side  911 , which is one example of a first side, among four sides forming the rectangular outline of the module substrate  91 . Accordingly, the RF input terminal  110  is arranged in the vicinity of the side  911 . 
     The RF output terminals  121  and  122 , each of which is one of the external connection terminals  150 , are arranged in a region  914  (hatched region) on the main surface  91   b.  The region  914  is an example of a second region, and is a virtual region extending along a side  913 , which is an example of a second side, among the four sides forming the external outline of the module substrate  91 . Accordingly, the RF output terminals  121  and  122  are arranged in the vicinity of the side  913  facing the side  911 , and are arranged away from the RF input terminal  110 . 
     The ground terminals GND are arranged between the RF input terminal  110  and each of the RF output terminals  121  and  122 . In  FIG.  2 B , two ground terminals GND, which are larger than the other RF input terminal  110 , are arranged in a central region on the main surface  91   b,  positioned between the regions  912  and  914 . 
     [1.3 Effects] 
     As described above, the RF module  1  according to the present embodiment includes: the module substrate  91  having the main surfaces  91   a  and  91   b  facing each other and having an outline that is rectangular in plan view; the external connection terminals  150  arranged on the main surface  91   b  and including the RF input terminal  110  for receiving an amplified transmission signal from the outside, the RF output terminals  121  and  124  for supplying a reception signal to the outside, and the antenna connection terminal  100 ; the filter  64  arranged on the main surface  91   a,  connected between the RF input terminal  110 /the RF output terminal  124  and the antenna connection terminal  100 , and having a passband including communication band D for TDD; and the filter  61  arranged on the main surface  91   a,  connected between the RF output terminal  121  and the antenna connection terminal  100 , and having a passband including at least part of communication band A allowed for simultaneous communication with communication band D. The RF input terminal  110  is arranged in the region  912  on the main surface  91   b,  extending along the side  911  among the four sides forming the rectangular outline of the module substrate  91 . The RF output terminal  121  is arranged in the region  914  on the main surface  91   b,  extending along the side  913  facing the side  911 , among the four sides forming the rectangular outline of the module substrate  91 . 
     Accordingly, the RF input terminal  110 , to which an amplified transmission signal in communication band D is input, can be arranged in the vicinity of the side  911  of the module substrate  91 , and the RF output terminal  121 , from which a reception signal in communication band A allowed for simultaneous communication with communication band D is output, can be arranged in the vicinity of the side  913  facing the side  911  of the module substrate  91 . Therefore, the distance between the RF input terminal  110  and the RF output terminal  121  can be increased on the main surface  91   b  of the module substrate  91 , thereby improving the isolation of the RF input terminal  110  and the RF output terminal  121 . As a result, in the case where simultaneous communication is performed in communication bands A and D, the interference between an amplified transmission signal flowing through the RF input terminal  110  and a reception signal flowing through the RF output terminal  121  can be suppressed, thereby improving the reception sensitivity. In particular, in the present embodiment, since an amplified transmission signal flows through the RF input terminal  110 , the improvement in the reception sensitivity due to the suppression of the interference between a transmission signal and a reception signal is remarkable. 
     Moreover, for example, in the RF module  1  according to the present embodiment, the external connection terminals  150  may further include the ground terminal GND arranged between the RF input terminal  110  and the RF output terminal  121 . 
     Accordingly, since the ground terminal GND is arranged between the RF input terminal  110  and the RF output terminal  121 , the interference between an amplified transmission signal flowing through the RF input terminal  110  and a reception signal flowing through the RF output terminal  121  can be further suppressed. 
     Furthermore, for example, the RF module  1  according to the present embodiment may further include the semiconductor IC  20  arranged on the main surface  91   a  or  91   b  and having an outline that is rectangular in plan view. The semiconductor IC  20  includes: the switch  51  connected between the antenna connection terminal  100  and the filters  61  and  64 ; the low noise amplifier  21  connected between the filter  61  and the RF output terminal  121 ; the terminal  201  connected to the antenna connection terminal  100  and connected to the switch  51  in the semiconductor IC  20 ; and the terminal  206  connected to the RF output terminal  121  and connected to the output of the low noise amplifier  21  in the semiconductor IC  20 . The terminal  201  may be arranged in the region  212  extending along the side  211  among the four sides forming the rectangular outline of the semiconductor IC  20 , and the terminal  206  may be arranged in the region  214  extending along the side  213  facing the side  211 , among the four sides forming the rectangular outline of the semiconductor IC  20 . 
     Accordingly, the terminal  201  through which a transmission signal in communication band D flows can be arranged in the vicinity of the side  211  of the semiconductor IC  20 , and the terminal  206  through which a reception signal in communication band A flows can be arranged in the vicinity of the side  213  facing the side  211  of the semiconductor IC  20 . Therefore, the distance between the terminals  201  and  206  can be increased in the semiconductor IC  20 , thereby improving the isolation of the terminals  201  and  206 . As a result, in the case where simultaneous communication is performed in communication bands A and D, the interference between an amplified transmission signal flowing through the terminal  201  and a reception signal flowing through the terminal  206  can be suppressed, thereby improving the reception sensitivity. 
     Meanwhile, for example, the RF module  1  according to the present embodiment may further include the filter  63  arranged on the main surface  91   a,  connected between the RF output terminal  123  for supplying a reception signal to the outside and the antenna connection terminal  100 , and having a passband including at least part of communication band C not allowed for simultaneous communication with communication band D. Each of the wire  84  connecting the filter  64  and the switch  51  and the wire  81  connecting the filter  61  and the switch  51  may be shorter than the wire  83  connecting the filter  63  and the switch  51 . 
     Accordingly, the length of the wires  81  and  84  between the filter  61 /the filter  64  and the switch  51  used in simultaneous communication can be reduced. Therefore, the wiring loss and mismatching loss due to the wires  81  and  84  can be reduced, and the electrical characteristics (such as noise figure (NF)) of the RF module  1  in simultaneous communication can be improved. 
     Moreover, for example, the RF module  1  according to the present embodiment may further include a conductive component arranged between the filter  61  and the filter  64 . 
     Accordingly, a conductive component may be arranged between the filter  61  through which a reception signal in communication band A flows and the filter  64  through which a transmission signal and a reception signal in communication band D flow. Therefore, the isolation of the filters  61  and  64  can be improved, and the interference between a transmission signal in communication band D and a reception signal in communication band A can be suppressed, thereby improving the reception sensitivity. 
     Furthermore, for example, in the RF module  1  according to the present embodiment, the conductive component may include the filter  63 , which is connected between the RF output terminal  123  for supplying a reception signal to the outside and the antenna connection terminal  100 , and which has a passband including at least part of communication band C not allowed for simultaneous communication with communication band D. 
     Accordingly, the filter  63  passing a reception signal in communication band C not allowed for simultaneous communication with communication band A can be used as a conductive component arranged between the filter  61  and the filter  64 . 
     In addition, for example, in the RF module  1  according to the present embodiment, communication band D may be Band  41  for LTE or n41 for 5GNR. 
     Accordingly, Band  41  or n41 can be used as communication band D. 
     Moreover, for example, in the RF module  1  according to the present embodiment, communication band A may be Band  1  or Band  3  for LTE or n75 or n76 for 5GNR. 
     Accordingly, Band  1 , Band  3 , n75, or n76 can be used as communication band A. 
     Furthermore, for example, in the RF module  1  according to the present embodiment, communication band C may be Band  7  or Band  40  for LTE. 
     Accordingly, Band  7  or Band  40  can be used as communication band C. 
     The communication device  5  according to the present embodiment includes the RFIC  3  processing an RF signal and the RF module  1  transmitting an RF signal between the RFIC  3  and the antenna  2 . 
     Accordingly, the communication device  5  can achieve effects that are the same as or similar to those of the RF module  1 . 
     Other Embodiments 
     As described above, although the RF module and the communication device according to the present disclosure have been described based on the embodiment, the RF module and the communication device according to the present disclosure are not limited to the above embodiment. Another embodiment realized by combining any components in the above embodiment, a modification obtained by applying various modifications conceivable to those skilled in the art to the above embodiment without necessarily departing from the gist of the present disclosure, and various devices with the built-in RF module and communication device are also included in the present disclosure. 
     For example, in the circuit configuration of the RF module and the communication device according to the above embodiment, another circuit element and wire may be inserted in a path connecting the circuit elements and signal paths illustrated in the drawings. For example, in the above embodiment, a filter may be inserted between the antenna connection terminal  100  and the switch  51 . Alternatively, for example, matching circuits may be inserted between the filters  61  to  64  and the low noise amplifiers  21  to  24 . 
     Although the filter  63  is arranged between the filters  61  and  62  and the filter  64  in the above embodiment, the filter  63  is not the only possible component arranged between the filters  61  and  62  and the filter  64 . For example, the matching circuit  73 , a control circuit (not illustrated), a power supply circuit (not illustrated), or a metal wall may be arranged between at least one of the filters  61  and  62  and the filter  64 . That is, another conductive component may be arranged between the filters  61  and  62  and the filter  64 . In addition, no conductive component may be arranged between the filters  61  and  62  and the filter  64 . 
     Note that, although the main surfaces  91   a  and  91   b  of the module substrate  91  are not molded with a resin member in the above embodiment, this is not the only possible case. That is, the main surfaces  91   a  and/or  91   b  of the module substrate  91  may be molded with a resin member. In this case, the surface of the resin member may be covered with a shield electrode layer. 
     Note that, although the ground terminals GND are arranged between the RF input terminal  110  and the RF output terminals  121 / 122  in the above embodiment, this is not the only possible case. That is, no ground terminal GND may be arranged between the RF input terminal  110  and the RF output terminals  121 / 122 . 
     Note that, although the low noise amplifiers  21  to  24  and the switches  51  and  52  are built into the single semiconductor IC  20  in the above embodiment, this is not the only possible case. For example, neither low noise amplifier nor switch may be provided. Each of the low noise amplifiers  21  to  24  and the switches  51  and  52  may be a separate surface mount device. In addition, the low noise amplifiers  21  to  24  and the switches  51  and  52  may be built in any combination into multiple semiconductor ICs. 
     Note that, although the semiconductor IC  20  is arranged on the main surface  91   a  of the module substrate  91  in the above embodiment, the semiconductor IC  20  may be arranged on the main surface  91   b.    
     Note that, although each of the wires  81 ,  82 , and  84  is shorter than the wire  83  in the above embodiment, this is not the only possible case. For example, at least one of the wires  81 ,  82 , and  84  may be longer than the wire  83 . 
     INDUSTRIAL APPLICABILITY 
     The present disclosure can be widely used as an RF module arranged in a front-end portion in communication devices such as mobile phones. 
     REFERENCE SIGNS LIST 
     
         
         
           
               1  RF module 
               2  antenna 
               3  RFIC 
               4  BBIC 
               5  communication device 
               20  semiconductor IC 
               21 ,  22 ,  23 , and  24  low noise amplifiers 
               51  and  52  switches 
               61 ,  62 ,  63 , and  64  filters 
               71 ,  72 , and  73  matching circuits 
               91  module substrate 
               91   a  and  91   b  main surfaces 
               100  antenna connection terminal 
               110  RF input terminal 
               121 ,  122 ,  123 , and  124  RF output terminals 
               150  external connection terminals 
               201 ,  202 ,  203 ,  204 ,  205 ,  206 ,  511 ,  512 ,  513 ,  514 ,  521 ,  522 , and  523  terminals 
               611 ,  621 , and  631  input terminals 
               612 ,  622 , and  632  output terminals 
               641  and  642  input/output terminals 
               911  and  913  sides 
               912  and  914  regions 
             GND ground terminals